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  • [css only gradient background] problems with ff < 3.6

    - by Luca
    hi! :) anyone know if is possible to reproduce this effect background-image: -moz-linear-gradient(top, #666666, #000000); background-image: -webkit-gradient(linear,left bottom,left top,color-stop(0, #000000),color-stop(1, #666666)); also on ff < 3.6? im tryin' to generate a gradient background without images! thanks a lot in advance for any advice.

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  • I can't click the links in Firefox and Chrome (they work in IE7)

    - by janoChen
    Its the weirdest thing I've ever seen. I can't click the last 3 links in the following code (when I use FF or Chrome): HTML: <div id="leftmanulist"> <div class="abouttop"> <ul class="aboutlist"> <li class="index"><a>????</a></li> <li><a href="instruments.html">????</a></li> <li><a href="performance.html">????</a></li> <li><a href="clothes.html">????</a></li> <li><a href="aboutfalundafa.html">??????</a></li> <li><a href="awards.html">????</a></li> </ul> </div> <div class="aboutbutton"></div> </div> CSS: #leftmanulist{ background:url("images/abouttop.gif") no-repeat; float: left; margin: 2px 2px 5px 30px; padding:39px 0 0 0; width:237px;} #leftmanulist ul li{line-height:35px;text-align:left; text-decoration:none;} #leftmanulist ul li a{ text-decoration:none;} #leftmanulist ul li:hover{ color:#0068FF;} #leftmanulist ul li a:hover{ color:#0068FF;} #leftmanulist ul li.index{ color:#0068FF;} #leftmanulist ul li.index a{ color:#0068FF;} .abouttop{background:url("images/leftmanulist_z.gif") repeat-y ; padding:0 6px; position:relative; z-index:0; width:237px;} .aboutlist{position:relative;left:28px;} .aboutbutton{background:url("images/leftmanulist_b.gif") no-repeat; width:237px; height:20px; position:relative; top:-17px; z-index:2;}

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  • Pattern match and replace in Javascript

    - by T_t
    There is something in my mind: In a web page,there are lots of things we can see from our browser.One of them is text. Now i have some patterns,"abc","hello",or some other strings.In the text, i want to find all the patterns and change the color or background-color of them. Like this: text: what a wonderful day! pattern: "a","day" resulet: what a wonderful day! How can solve this whit Javascript?

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  • What does the $1$2$4 mean in this preg_replace?

    - by Taylor
    Got this function for ammending the query string and was wondering what the replacement part of the pre_replace meant (ie- $1$2$4). function add_querystring_var($url, $key, $value) { $url = preg_replace('/(.*)(\?|&)' . $key . '=[^&]+?(&)(.*)/i', '$1$2$4', $url . '&'); $url = substr($url, 0, -1); if (strpos($url, '?') === false) { return ($url . '?' . $key . '=' . $value); } else { return ($url . '&' . $key . '=' . $value); } } Not too familiar with regular expression stuff. I get the various parts to preg_replace but not 100% about the use of '$1$2$4' in the replacement part.

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  • AutoMapper MappingFunction from Source Type of NameValueCollection

    - by REA_ANDREW
    I have had a situation arise today where I need to construct a complex type from a source of a NameValueCollection.  A little while back I submitted a patch for the Agatha Project to include REST (JSON and XML) support for the service contract.  I realized today that as useful as it is, it did not actually support true REST conformance, as REST should support GET so that you can use JSONP from JavaScript directly meaning you can query cross domain services.  My original implementation for POX and JSON used the POST method and this immediately rules out JSONP as from reading, JSONP only works with GET Requests. This then raised another issue.  The current operation contract of Agatha and one of its main benefits is that you can supply an array of Request objects in a single request, limiting the about of server requests you need to make.  Now, at the present time I am thinking that this will not be the case for the REST imlementation but will yield the benefits of the fact that : The same Request objects can be used for SOAP and RST (POX, JSON) The construct of the JavaScript functions will be simpler and more readable It will enable the use of JSONP for cross domain REST Services The current contract for the Agatha WcfRequestProcessor is at time of writing the following: [ServiceContract] public interface IWcfRequestProcessor { [OperationContract(Name = "ProcessRequests")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] Response[] Process(params Request[] requests); [OperationContract(Name = "ProcessOneWayRequests", IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] void ProcessOneWayRequests(params OneWayRequest[] requests); }   My current proposed solution, and at the very early stages of my concept is as follows: [ServiceContract] public interface IWcfRestJsonRequestProcessor { [OperationContract(Name="process")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] [WebGet(UriTemplate = "process/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] Response[] Process(string name, NameValueCollection parameters); [OperationContract(Name="processoneway",IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [WebGet(UriTemplate = "process-one-way/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] void ProcessOneWayRequests(string name, NameValueCollection parameters); }   Now this part I have not yet implemented, it is the preliminart step which I have developed which will allow me to take the name of the Request Type and the NameValueCollection and construct the complex type which is that of the Request which I can then supply to a nested instance of the original IWcfRequestProcessor  and work as it should normally.  To give an example of some of the urls which you I envisage with this method are: http://www.url.com/service.svc/json/process/getweather/?location=london http://www.url.com/service.svc/json/process/getproductsbycategory/?categoryid=1 http://www.url.om/service.svc/json/process/sayhello/?name=andy Another reason why my direction has gone to a single request for the REST implementation is because of restrictions which are imposed by browsers on the length of the url.  From what I have read this is on average 2000 characters.  I think that this is a very acceptable usage limit in the context of using 1 request, but I do not think this is acceptable for accommodating multiple requests chained together.  I would love to be corrected on that one, I really would but unfortunately from what I have read I have come to the conclusion that this is not the case. The mapping function So, as I say this is just the first pass I have made at this, and I am not overly happy with the try catch for detecting types without default constructors.  I know there is a better way but for the minute, it escapes me.  I would also like to know the correct way for adding mapping functions and not using the anonymous way that I have used.  To achieve this I have used recursion which I am sure is what other mapping function use. As you do have to go as deep as the complex type is. public static object RecurseType(NameValueCollection collection, Type type, string prefix) { try { var returnObject = Activator.CreateInstance(type); foreach (var property in type.GetProperties()) { foreach (var key in collection.AllKeys) { if (String.IsNullOrEmpty(prefix) || key.Length > prefix.Length) { var propertyNameToMatch = String.IsNullOrEmpty(prefix) ? key : key.Substring(property.Name.IndexOf(prefix) + prefix.Length + 1); if (property.Name == propertyNameToMatch) { property.SetValue(returnObject, Convert.ChangeType(collection.Get(key), property.PropertyType), null); } else if(property.GetValue(returnObject,null) == null) { property.SetValue(returnObject, RecurseType(collection, property.PropertyType, String.Concat(prefix, property.PropertyType.Name)), null); } } } } return returnObject; } catch (MissingMethodException) { //Quite a blunt way of dealing with Types without default constructor return null; } }   Another thing is performance, I have not measured this in anyway, it is as I say the first pass, so I hope this can be the start of a more perfected implementation.  I tested this out with a complex type of three levels, there is no intended logical meaning to the properties, they are simply for the purposes of example.  You could call this a spiking session, as from here on in, now I know what I am building I would take a more TDD approach.  OK, purists, why did I not do this from the start, well I didn’t, this was a brain dump and now I know what I am building I can. The console test and how I used with AutoMapper is as follows: static void Main(string[] args) { var collection = new NameValueCollection(); collection.Add("Name", "Andrew Rea"); collection.Add("Number", "1"); collection.Add("AddressLine1", "123 Street"); collection.Add("AddressNumber", "2"); collection.Add("AddressPostCodeCountry", "United Kingdom"); collection.Add("AddressPostCodeNumber", "3"); AutoMapper.Mapper.CreateMap<NameValueCollection, Person>() .ConvertUsing(x => { return(Person) RecurseType(x, typeof(Person), null); }); var person = AutoMapper.Mapper.Map<NameValueCollection, Person>(collection); Console.WriteLine(person.Name); Console.WriteLine(person.Number); Console.WriteLine(person.Address.Line1); Console.WriteLine(person.Address.Number); Console.WriteLine(person.Address.PostCode.Country); Console.WriteLine(person.Address.PostCode.Number); Console.ReadLine(); }   Notice the convention that I am using and that this method requires you do use.  Each property is prefixed with the constructed name of its parents combined.  This is the convention used by AutoMapper and it makes sense. I can also think of other uses for this including using with ASP.NET MVC ModelBinders for creating a complex type from the QueryString which is itself is a NameValueCollection. Hope this is of some help to people and I would welcome any code reviews you could give me. References: Agatha : http://code.google.com/p/agatha-rrsl/ AutoMapper : http://automapper.codeplex.com/   Cheers for now, Andrew   P.S. I will have the proposed solution for a more complete REST implementation for AGATHA very soon. 

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  • How to subscribe to the free Oracle Linux errata yum repositories

    - by Lenz Grimmer
    Now that updates and errata for Oracle Linux are available for free (both as in beer and freedom), here's a quick HOWTO on how to subscribe your Oracle Linux system to the newly added yum repositories on our public yum server, assuming that you just installed Oracle Linux from scratch, e.g. by using the installation media (ISO images) available from the Oracle Software Delivery Cloud You need to download the appropriate yum repository configuration file from the public yum server and install it in the yum repository directory. For Oracle Linux 6, the process would look as follows: as the root user, run the following command: [root@oraclelinux62 ~]# wget http://public-yum.oracle.com/public-yum-ol6.repo \ -P /etc/yum.repos.d/ --2012-03-23 00:18:25-- http://public-yum.oracle.com/public-yum-ol6.repo Resolving public-yum.oracle.com... 141.146.44.34 Connecting to public-yum.oracle.com|141.146.44.34|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 1461 (1.4K) [text/plain] Saving to: “/etc/yum.repos.d/public-yum-ol6.repo” 100%[=================================================>] 1,461 --.-K/s in 0s 2012-03-23 00:18:26 (37.1 MB/s) - “/etc/yum.repos.d/public-yum-ol6.repo” saved [1461/1461] For Oracle Linux 5, the file name would be public-yum-ol5.repo in the URL above instead. The "_latest" repositories that contain the errata packages are already enabled by default — you can simply pull in all available updates by running "yum update" next: [root@oraclelinux62 ~]# yum update Loaded plugins: refresh-packagekit, security ol6_latest | 1.1 kB 00:00 ol6_latest/primary | 15 MB 00:42 ol6_latest 14643/14643 Setting up Update Process Resolving Dependencies --> Running transaction check ---> Package at.x86_64 0:3.1.10-43.el6 will be updated ---> Package at.x86_64 0:3.1.10-43.el6_2.1 will be an update ---> Package autofs.x86_64 1:5.0.5-39.el6 will be updated ---> Package autofs.x86_64 1:5.0.5-39.el6_2.1 will be an update ---> Package bind-libs.x86_64 32:9.7.3-8.P3.el6 will be updated ---> Package bind-libs.x86_64 32:9.7.3-8.P3.el6_2.2 will be an update ---> Package bind-utils.x86_64 32:9.7.3-8.P3.el6 will be updated ---> Package bind-utils.x86_64 32:9.7.3-8.P3.el6_2.2 will be an update ---> Package cvs.x86_64 0:1.11.23-11.el6_0.1 will be updated ---> Package cvs.x86_64 0:1.11.23-11.el6_2.1 will be an update [...] ---> Package yum.noarch 0:3.2.29-22.0.1.el6 will be updated ---> Package yum.noarch 0:3.2.29-22.0.2.el6_2.2 will be an update ---> Package yum-plugin-security.noarch 0:1.1.30-10.el6 will be updated ---> Package yum-plugin-security.noarch 0:1.1.30-10.0.1.el6 will be an update ---> Package yum-utils.noarch 0:1.1.30-10.el6 will be updated ---> Package yum-utils.noarch 0:1.1.30-10.0.1.el6 will be an update --> Finished Dependency Resolution Dependencies Resolved ===================================================================================== Package Arch Version Repository Size ===================================================================================== Installing: kernel x86_64 2.6.32-220.7.1.el6 ol6_latest 24 M kernel-uek x86_64 2.6.32-300.11.1.el6uek ol6_latest 21 M kernel-uek-devel x86_64 2.6.32-300.11.1.el6uek ol6_latest 6.3 M Updating: at x86_64 3.1.10-43.el6_2.1 ol6_latest 60 k autofs x86_64 1:5.0.5-39.el6_2.1 ol6_latest 470 k bind-libs x86_64 32:9.7.3-8.P3.el6_2.2 ol6_latest 839 k bind-utils x86_64 32:9.7.3-8.P3.el6_2.2 ol6_latest 178 k cvs x86_64 1.11.23-11.el6_2.1 ol6_latest 711 k [...] xulrunner x86_64 10.0.3-1.0.1.el6_2 ol6_latest 12 M yelp x86_64 2.28.1-13.el6_2 ol6_latest 778 k yum noarch 3.2.29-22.0.2.el6_2.2 ol6_latest 987 k yum-plugin-security noarch 1.1.30-10.0.1.el6 ol6_latest 36 k yum-utils noarch 1.1.30-10.0.1.el6 ol6_latest 94 k Transaction Summary ===================================================================================== Install 3 Package(s) Upgrade 96 Package(s) Total download size: 173 M Is this ok [y/N]: y Downloading Packages: (1/99): at-3.1.10-43.el6_2.1.x86_64.rpm | 60 kB 00:00 (2/99): autofs-5.0.5-39.el6_2.1.x86_64.rpm | 470 kB 00:01 (3/99): bind-libs-9.7.3-8.P3.el6_2.2.x86_64.rpm | 839 kB 00:02 (4/99): bind-utils-9.7.3-8.P3.el6_2.2.x86_64.rpm | 178 kB 00:00 [...] (96/99): yelp-2.28.1-13.el6_2.x86_64.rpm | 778 kB 00:02 (97/99): yum-3.2.29-22.0.2.el6_2.2.noarch.rpm | 987 kB 00:03 (98/99): yum-plugin-security-1.1.30-10.0.1.el6.noarch.rpm | 36 kB 00:00 (99/99): yum-utils-1.1.30-10.0.1.el6.noarch.rpm | 94 kB 00:00 ------------------------------------------------------------------------------------- Total 306 kB/s | 173 MB 09:38 warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY Retrieving key from http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 Importing GPG key 0xEC551F03: Userid: "Oracle OSS group (Open Source Software group) " From : http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 Is this ok [y/N]: y Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Updating : yum-3.2.29-22.0.2.el6_2.2.noarch 1/195 Updating : xorg-x11-server-common-1.10.4-6.el6_2.3.x86_64 2/195 Updating : kernel-uek-headers-2.6.32-300.11.1.el6uek.x86_64 3/195 Updating : 12:dhcp-common-4.1.1-25.P1.el6_2.1.x86_64 4/195 Updating : tzdata-java-2011n-2.el6.noarch 5/195 Updating : tzdata-2011n-2.el6.noarch 6/195 Updating : glibc-common-2.12-1.47.el6_2.9.x86_64 7/195 Updating : glibc-2.12-1.47.el6_2.9.x86_64 8/195 [...] Cleanup : kernel-firmware-2.6.32-220.el6.noarch 191/195 Cleanup : kernel-uek-firmware-2.6.32-300.3.1.el6uek.noarch 192/195 Cleanup : glibc-common-2.12-1.47.el6.x86_64 193/195 Cleanup : glibc-2.12-1.47.el6.x86_64 194/195 Cleanup : tzdata-2011l-4.el6.noarch 195/195 Installed: kernel.x86_64 0:2.6.32-220.7.1.el6 kernel-uek.x86_64 0:2.6.32-300.11.1.el6uek kernel-uek-devel.x86_64 0:2.6.32-300.11.1.el6uek Updated: at.x86_64 0:3.1.10-43.el6_2.1 autofs.x86_64 1:5.0.5-39.el6_2.1 bind-libs.x86_64 32:9.7.3-8.P3.el6_2.2 bind-utils.x86_64 32:9.7.3-8.P3.el6_2.2 cvs.x86_64 0:1.11.23-11.el6_2.1 dhclient.x86_64 12:4.1.1-25.P1.el6_2.1 [...] xorg-x11-server-common.x86_64 0:1.10.4-6.el6_2.3 xulrunner.x86_64 0:10.0.3-1.0.1.el6_2 yelp.x86_64 0:2.28.1-13.el6_2 yum.noarch 0:3.2.29-22.0.2.el6_2.2 yum-plugin-security.noarch 0:1.1.30-10.0.1.el6 yum-utils.noarch 0:1.1.30-10.0.1.el6 Complete! At this point, your system is fully up to date. As the kernel was updated as well, a reboot is the recommended next action. If you want to install the latest release of the Unbreakable Enterprise Kernel Release 2 as well, you need to edit the .repo file and enable the respective yum repository (e.g. "ol6_UEK_latest" for Oracle Linux 6 and "ol5_UEK_latest" for Oracle Linux 5) manually, by setting enabled to "1". The next yum update run will download and install the second release of the Unbreakable Enterprise Kernel, which will be enabled after the next reboot. -Lenz

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  • Make your CHM Help Files show HTML5 and CSS3 content

    - by Rick Strahl
    The HTML Help 1.0 specification aka CHM files, is pretty old. In fact, it's practically ancient as it was introduced in 1997 when Internet Explorer 4 was introduced. Html Help 1.0 is basically a completely HTML based Help system that uses a Help Viewer that internally uses Internet Explorer to render the HTML Help content. Because of its use of the Internet Explorer shell for rendering there were many security issues in the past, which resulted in locking down of the Web Browser control in Windows and also the Help Engine which caused some unfortunate side effects. Even so, CHM continues to be a popular help format because it is very easy to produce content for it, using plain HTML and because it works with many Windows application platforms out of the box. While there have been various attempts to replace CHM help files CHM files still seem to be a popular choice for many applications to display their help systems. The biggest alternative these days is no system based help at all, but links to online documentation. For Windows apps though it's still very common to see CHM help files and there are still a ton of CHM help out there and lots of tools (including our own West Wind Html Help Builder) that produce output for CHM files as well as Web output. Image is Everything and you ain't got it! One problem with the CHM engine is that it's stuck with an ancient Internet Explorer version for rendering. For example if you have help content that uses HTML5 or CSS3 content you might have an HTML Help topic like the following shown here in a full Web Browser instance of Internet Explorer: The page clearly uses some CSS3 features like rounded corners and box shadows that are rendered using plain CSS 3 features. Note that I used Internet Explorer on purpose here to demonstrate that IE9 on Windows 7 can properly render this content using some of the new features of CSS, but the same is true for all other recent versions of the major browsers (FireFox 3.1+, Safari 4.5+, WebKit 9+ etc.). Unfortunately if you take this nice and simple CSS3 content and run it through the HTML Help compiler to produce a CHM file the resulting output on the same machine looks a bit less flashy: All the CSS3 styling is gone and although the page display and functionality still works, but all the extra styling features are gone. This even though I am running this on a Windows 7 machine that has IE9 that should be able to render these CSS features. Bummer. Web Browser Control - perpetually stuck in IE 7 Mode The problem is the Web Browser/Shell Components in Windows. This component is and has been part of Windows for as long as Internet Explorer has been around, but the Web Browser control hasn't kept up with the latest versions of IE. In a nutshell the control is stuck in IE7 rendering mode for engine compatibility reasons by default. However, there is at least one way to fix this explicitly using Registry keys on a per application basis. The key point from that blog article is that you can override the IE rendering engine for a particular executable by setting one (or more) registry flags that tell the Windows Shell which version of the Internet Explorer rendering engine to load. An application that wishes to use a more recent version of Internet Explorer can then register itself during installation for the specific IE version desired and from then on the application will use that version of the Web Browser component. If the application is older than the specified version it falls back to the default version (IE 7 rendering). Forcing CHM files to display with IE9 (or later) Rendering Knowing that we can force the IE usage for a given process it's also possible to affect the CHM rendering by setting same keys on the executable that's hosting the CHM file. What that executable file is depends on the type of application as there are a number of ways that can launch the help engine. hh.exeThe standalone Windows CHM Help Viewer that launches when you launch a CHM from Windows Explorer. You can manually add hh.exe to the registry keys. YourApplication.exeIf you're using .NET or any tool that internally uses the hhControl ActiveX control to launch help content your application is your host. You should add your application's exe to the registry during application startup. foxhhelp9.exeIf you're building a FoxPro application that uses the built-in help features, foxhhelp9.exe is used to actually host the help controls. Make sure to add this executable to the registry. What to set You can configure the Internet Explorer version used for an application in the registry by specifying the executable file name and a value that specifies the IE version desired. There are two different sets of keys for 32 bit and 64 bit applications. 32 bit only or 64 bit: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_BROWSER_EMULATION Value Key: hh.exe 32 bit on 64 bit machine: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\MAIN\FeatureControl\FEATURE_BROWSER_EMULATION Value Key: hh.exe Note that it's best to always set both values ideally when you install your application so it works regardless of which platform you run on. The value specified is a DWORD value and the interesting values are decimal 9000 for IE9 rendering mode depending on !DOCTYPE settings or 9999 for IE 9 standards mode always. You can use the same logic for 8000 and 8888 for IE8 and the final value of 7000 for IE7 (one has to wonder what they're going todo for version 10 to perpetuate that pattern). I think 9000 is the value you'd most likely want to use. 9000 means that IE9 will be used for rendering but unless the right doctypes are used (XHTML and HTML5 specifically) IE will still fall back into quirks mode as needed. This should allow existing pages to continue to use the fallback engine while new pages that have the proper HTML doctype set can take advantage of the newest features. Here's an example of how I set the registry keys in my Tarma Installmate registry configuration: Note that I set all three values both under the Software and Wow6432Node keys so that this works regardless of where these EXEs are launched from. Even though all apps are 32 bit apps, the 64 bit (the default one shown selected) key is often used. So, now once I've set the registry key for hh.exe I can now launch my CHM help file from Explorer and see the following CSS3 IE9 rendered display: Summary It sucks that we have to go through all these hoops to get what should be natural behavior for an application to support the latest features available on a system. But it shouldn't be a surprise - the Windows Help team (if there even is such a thing) has not been known for forward looking technologies. It's a pretty big hassle that we have to resort to setting registry keys in order to get the Web Browser control and the internal CHM engine to render itself properly but at least it's possible to make it work after all. Using this technique it's possible to ship an application with a help file and allow your CHM help to display with richer CSS markup and correct rendering using the stricter and more consistent XHTML or HTML5 doctypes. If you provide both Web help and in-application help (and why not if you're building from a single source) you now can side step the issue of your customers asking: Why does my help file look so much shittier than the online help… No more!© Rick Strahl, West Wind Technologies, 2005-2012Posted in HTML5  Help  Html Help Builder  Internet Explorer  Windows   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Dynamically creating a Generic Type at Runtime

    - by Rick Strahl
    I learned something new today. Not uncommon, but it's a core .NET runtime feature I simply did not know although I know I've run into this issue a few times and worked around it in other ways. Today there was no working around it and a few folks on Twitter pointed me in the right direction. The question I ran into is: How do I create a type instance of a generic type when I have dynamically acquired the type at runtime? Yup it's not something that you do everyday, but when you're writing code that parses objects dynamically at runtime it comes up from time to time. In my case it's in the bowels of a custom JSON parser. After some thought triggered by a comment today I realized it would be fairly easy to implement two-way Dictionary parsing for most concrete dictionary types. I could use a custom Dictionary serialization format that serializes as an array of key/value objects. Basically I can use a custom type (that matches the JSON signature) to hold my parsed dictionary data and then add it to the actual dictionary when parsing is complete. Generic Types at Runtime One issue that came up in the process was how to figure out what type the Dictionary<K,V> generic parameters take. Reflection actually makes it fairly easy to figure out generic types at runtime with code like this: if (arrayType.GetInterface("IDictionary") != null) { if (arrayType.IsGenericType) { var keyType = arrayType.GetGenericArguments()[0]; var valueType = arrayType.GetGenericArguments()[1]; … } } The GetArrayType method gets passed a type instance that is the array or array-like object that is rendered in JSON as an array (which includes IList, IDictionary, IDataReader and a few others). In my case the type passed would be something like Dictionary<string, CustomerEntity>. So I know what the parent container class type is. Based on the the container type using it's then possible to use GetGenericTypeArguments() to retrieve all the generic types in sequential order of definition (ie. string, CustomerEntity). That's the easy part. Creating a Generic Type and Providing Generic Parameters at RunTime The next problem is how do I get a concrete type instance for the generic type? I know what the type name and I have a type instance is but it's generic, so how do I get a type reference to keyvaluepair<K,V> that is specific to the keyType and valueType above? Here are a couple of things that come to mind but that don't work (and yes I tried that unsuccessfully first): Type elementType = typeof(keyvalue<keyType, valueType>); Type elementType = typeof(keyvalue<typeof(keyType), typeof(valueType)>); The problem is that this explicit syntax expects a type literal not some dynamic runtime value, so both of the above won't even compile. I turns out the way to create a generic type at runtime is using a fancy bit of syntax that until today I was completely unaware of: Type elementType = typeof(keyvalue<,>).MakeGenericType(keyType, valueType); The key is the type(keyvalue<,>) bit which looks weird at best. It works however and produces a non-generic type reference. You can see the difference between the full generic type and the non-typed (?) generic type in the debugger: The nonGenericType doesn't show any type specialization, while the elementType type shows the string, CustomerEntity (truncated above) in the type name. Once the full type reference exists (elementType) it's then easy to create an instance. In my case the parser parses through the JSON and when it completes parsing the value/object it creates a new keyvalue<T,V> instance. Now that I know the element type that's pretty trivial with: // Objects start out null until we find the opening tag resultObject = Activator.CreateInstance(elementType); Here the result object is picked up by the JSON array parser which creates an instance of the child object (keyvalue<K,V>) and then parses and assigns values from the JSON document using the types  key/value property signature. Internally the parser then takes each individually parsed item and adds it to a list of  List<keyvalue<K,V>> items. Parsing through a Generic type when you only have Runtime Type Information When parsing of the JSON array is done, the List needs to be turned into a defacto Dictionary<K,V>. This should be easy since I know that I'm dealing with an IDictionary, and I know the generic types for the key and value. The problem is again though that this needs to happen at runtime which would mean using several Convert.ChangeType() calls in the code to dynamically cast at runtime. Yuk. In the end I decided the easier and probably only slightly slower way to do this is a to use the dynamic type to collect the items and assign them to avoid all the dynamic casting madness: else if (IsIDictionary) { IDictionary dict = Activator.CreateInstance(arrayType) as IDictionary; foreach (dynamic item in items) { dict.Add(item.key, item.value); } return dict; } This code creates an instance of the generic dictionary type first, then loops through all of my custom keyvalue<K,V> items and assigns them to the actual dictionary. By using Dynamic here I can side step all the explicit type conversions that would be required in the three highlighted areas (not to mention that this nested method doesn't have access to the dictionary item generic types here). Static <- -> Dynamic Dynamic casting in a static language like C# is a bitch to say the least. This is one of the few times when I've cursed static typing and the arcane syntax that's required to coax types into the right format. It works but it's pretty nasty code. If it weren't for dynamic that last bit of code would have been a pretty ugly as well with a bunch of Convert.ChangeType() calls to litter the code. Fortunately this type of type convulsion is rather rare and reserved for system level code. It's not every day that you create a string to object parser after all :-)© Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  CSharp   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Why Fusion Middleware matters to Oracle Applications and Fusion Applications customers?

    - by Harish Gaur
    Did you miss this general session on Monday morning presented by Amit Zavery, VP of Oracle Fusion Middleware Product Management? There will be a recording made available shortly and in the meanwhile, here is a recap. Amit presented 5 strategies customers can leverage today to extend their applications. Figure 1: 5 Oracle Fusion Middleware strategies to extend Oracle Applications & Oracle Fusion Apps 1. Engage Everyone – Provide intuitive and social experience for application users using Oracle WebCenter 2. Extend Enterprise – Extend Oracle Applications to mobile devices using Oracle ADF Mobile 3. Orchestrate Processes – Automate key organization processes across on-premise & cloud applications using Oracle BPM Suite & Oracle SOA Suite 4. Secure the core – Provide single sign-on and self-service provisioning across multiple apps using Oracle Identity Management 5. Optimize Performance – Leverage Exalogic stack to consolidate multiple instance and improve performance of Oracle Applications Session included 3 demonstrations to illustrate these strategies. 1. First demo highlighted significance of mobile applications for unlocking existing investment in Applications such as EBS. Using a native iPhone application interacting with e-Business Suite, demo showed how expense approval can be mobile enabled with enhanced visibility using BI dashboards. 2. Second demo showed how you can extend a banking process in Siebel and Oracle Policy Automation with Oracle BPM Suite.Process starts in Siebel with a customer requesting a loan, and then jumps to OPA for loan recommendations and decision making and loan processing with approvals in handled in BPM Suite. Once approvals are completed Siebel is updated to complete the process. 3. Final demo showcased FMW components inside Fusion Applications, specifically WebCenter. Boeing, Underwriter Laboratories and Electronic Arts joined this quest and discussed 3 different approaches of leveraging Fusion Middleware stack to maximize their investment in Oracle Applications and/or Fusion Applications technology. Let’s briefly review what these customers shared during the session: 1. Extend Fusion Applications We know that Oracle Fusion Middleware is the underlying technology infrastructure for Oracle Fusion Applications. Architecturally, Oracle Fusion Apps leverages several components of Oracle Fusion Middleware from Oracle WebCenter for rich collaborative interface, Oracle SOA Suite & Oracle BPM Suite for orchestrating key underlying processes to Oracle BIEE for dash boarding and analytics. Boeing talked about how they are using Oracle BPM Suite 11g, a key component of Oracle Fusion Middleware with Oracle Fusion Apps to transform their supply chain. Tim Murnin, Director of Supply Chain talked about Boeing’s 5 year supply chain transformation journey. Boeing’s Integrated and Information Management division began with automation of critical RFQ process using Oracle BPM Suite. This 1st phase resulted in 38% reduction in labor costs for RFP. As a next step in this effort, Boeing is now creating a platform to enable electronic Order Management. Fusion Apps are playing a significant role in this phase. Boeing has gone live with Oracle Fusion Product Hub and efforts are underway with Oracle Fusion Distributed Order Orchestration (DOO). So, where does Oracle BPM Suite 11g fit in this equation? Let me explain. Business processes within Fusion Apps are designed using 2 standards: Business Process Execution Language (BPEL) and Business Process Modeling Notation (BPMN). These processes can be easily configured using declarative set of tools. Boeing leverages Oracle BPM Suite 11g (which supports BPMN 2.0) and Oracle SOA Suite (which supports BPEL) to “extend” these applications. Traditionally, customizations are done within an app using native technologies. But, instead of making process changes within Fusion Apps, Boeing has taken an approach of building “extensions” layer on top of the application. Fig 2: Boeing’s use of Oracle BPM Suite to orchestrate key supply chain processes across Fusion Apps 2. Maximize Oracle Applications investment Fusion Middleware appeals not only to Fusion Apps customers, but is also leveraged by Oracle E-Business Suite, PeopleSoft, Siebel and JD Edwards customers significantly. Using Oracle BPM Suite and Oracle SOA Suite is the recommended extension strategy for Oracle Fusion Apps and Oracle Applications Unlimited customers. Electronic Arts, E-Business Suite customer, spoke about their strategy to transform their order-to-cash process using Oracle SOA Suite, Oracle Foundation Packs and Oracle BAM. Udesh Naicker, Sr Director of IT at Elecronic Arts (EA), discussed how growth of social and digital gaming had started to put tremendous pressure on EA’s existing IT infrastructure. He discussed the challenge with millions of micro-transactions coming from several sources – Microsoft Xbox, Paypal, several service providers. EA found Order-2-Cash processes stretched to their limits. They lacked visibility into these transactions across the entire value chain. EA began by consolidating their E-Business Suite R11 instances into single E-Business Suite R12. EA needed to cater to a variety of service requirements, connectivity methods, file formats, and information latency. Their integration strategy was tactical, i.e., using file uploads, TIBCO, SQL scripts. After consolidating E-Business suite, EA standardized their integration approach with Oracle SOA Suite and Oracle AIA Foundation Pack. Oracle SOA Suite is the platform used to extend E-Business Suite R12 and standardize 60+ interfaces across several heterogeneous systems including PeopleSoft, Demantra, SF.com, Workday, and Managed EDI services spanning on-premise, hosted and cloud applications. EA believes that Oracle SOA Suite 11g based extension strategy has helped significantly in the followings ways: - It helped them keep customizations out of E-Business Suite, thereby keeping EBS R12 vanilla and upgrade safe - Developers are now proficient in technology which is also leveraged by Fusion Apps. This has helped them prepare for adoption of Fusion Apps in the future Fig 3: Using Oracle SOA Suite & Oracle e-Business Suite, Electronic Arts built new platform for order processing 3. Consolidate apps and improve scalability Exalogic is an optimal platform for customers to consolidate their application deployments and enhance performance. Underwriter Laboratories talked about their strategy to run their mission critical applications including e-Business Suite on Exalogic. Christian Anschuetz, CIO of Underwriter Laboratories (UL) shared how UL is on a growth path - $1B to $2.5B in 5 years- and planning a significant business transformation from a not-for-profit to a for-profit business. To support this growth, UL is planning to simplify its IT environment and the deployment complexity associated with ERP applications and technology it runs on. Their current applications were deployed on variety of hardware platforms and lacked comprehensive disaster recovery architecture. UL embarked on a mission to deploy E-Business Suite on Exalogic. UL’s solution is unique because it is one of the first to deploy a large number of Oracle applications and related Fusion Middleware technologies (SOA, BI, Analytical Applications AIA Foundation Pack and AIA EBS to Siebel UCM prebuilt integration) on the combined Exalogic and Exadata environment. UL is planning to move to a virtualized architecture toward the end of 2012 to securely host external facing applications like iStore Fig 4: Underwrites Labs deployed e-Business Suite on Exalogic to achieve performance gains Key takeaways are: - Fusion Middleware platform is certified with major Oracle Applications Unlimited offerings. Fusion Middleware is the underlying technological infrastructure for Fusion Apps - Customers choose Oracle Fusion Middleware to extend their applications (Apps Unlimited or Fusion Apps) to keep applications upgrade safe and prepare for Fusion Apps - Exalogic is an optimum platform to consolidate applications deployments and enhance performance

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  • Why Fusion Middleware matters to Oracle Applications and Fusion Applications customers?

    - by Harish Gaur
    Did you miss this general session on Monday morning presented by Amit Zavery, VP of Oracle Fusion Middleware Product Management? There will be a recording made available shortly and in the meanwhile, here is a recap. Amit presented 5 strategies customers can leverage today to extend their applications. Figure 1: 5 Oracle Fusion Middleware strategies to extend Oracle Applications & Oracle Fusion Apps 1. Engage Everyone – Provide intuitive and social experience for application users using Oracle WebCenter 2. Extend Enterprise – Extend Oracle Applications to mobile devices using Oracle ADF Mobile 3. Orchestrate Processes – Automate key organization processes across on-premise & cloud applications using Oracle BPM Suite & Oracle SOA Suite 4. Secure the core – Provide single sign-on and self-service provisioning across multiple apps using Oracle Identity Management 5. Optimize Performance – Leverage Exalogic stack to consolidate multiple instance and improve performance of Oracle Applications Session included 3 demonstrations to illustrate these strategies. 1. First demo highlighted significance of mobile applications for unlocking existing investment in Applications such as EBS. Using a native iPhone application interacting with e-Business Suite, demo showed how expense approval can be mobile enabled with enhanced visibility using BI dashboards. 2. Second demo showed how you can extend a banking process in Siebel and Oracle Policy Automation with Oracle BPM Suite.Process starts in Siebel with a customer requesting a loan, and then jumps to OPA for loan recommendations and decision making and loan processing with approvals in handled in BPM Suite. Once approvals are completed Siebel is updated to complete the process. 3. Final demo showcased FMW components inside Fusion Applications, specifically WebCenter. Boeing, Underwriter Laboratories and Electronic Arts joined this quest and discussed 3 different approaches of leveraging Fusion Middleware stack to maximize their investment in Oracle Applications and/or Fusion Applications technology. Let’s briefly review what these customers shared during the session: 1. Extend Fusion Applications We know that Oracle Fusion Middleware is the underlying technology infrastructure for Oracle Fusion Applications. Architecturally, Oracle Fusion Apps leverages several components of Oracle Fusion Middleware from Oracle WebCenter for rich collaborative interface, Oracle SOA Suite & Oracle BPM Suite for orchestrating key underlying processes to Oracle BIEE for dash boarding and analytics. Boeing talked about how they are using Oracle BPM Suite 11g, a key component of Oracle Fusion Middleware with Oracle Fusion Apps to transform their supply chain. Tim Murnin, Director of Supply Chain talked about Boeing’s 5 year supply chain transformation journey. Boeing’s Integrated and Information Management division began with automation of critical RFQ process using Oracle BPM Suite. This 1st phase resulted in 38% reduction in labor costs for RFP. As a next step in this effort, Boeing is now creating a platform to enable electronic Order Management. Fusion Apps are playing a significant role in this phase. Boeing has gone live with Oracle Fusion Product Hub and efforts are underway with Oracle Fusion Distributed Order Orchestration (DOO). So, where does Oracle BPM Suite 11g fit in this equation? Let me explain. Business processes within Fusion Apps are designed using 2 standards: Business Process Execution Language (BPEL) and Business Process Modeling Notation (BPMN). These processes can be easily configured using declarative set of tools. Boeing leverages Oracle BPM Suite 11g (which supports BPMN 2.0) and Oracle SOA Suite (which supports BPEL) to “extend” these applications. Traditionally, customizations are done within an app using native technologies. But, instead of making process changes within Fusion Apps, Boeing has taken an approach of building “extensions” layer on top of the application. Fig 2: Boeing’s use of Oracle BPM Suite to orchestrate key supply chain processes across Fusion Apps 2. Maximize Oracle Applications investment Fusion Middleware appeals not only to Fusion Apps customers, but is also leveraged by Oracle E-Business Suite, PeopleSoft, Siebel and JD Edwards customers significantly. Using Oracle BPM Suite and Oracle SOA Suite is the recommended extension strategy for Oracle Fusion Apps and Oracle Applications Unlimited customers. Electronic Arts, E-Business Suite customer, spoke about their strategy to transform their order-to-cash process using Oracle SOA Suite, Oracle Foundation Packs and Oracle BAM. Udesh Naicker, Sr Director of IT at Elecronic Arts (EA), discussed how growth of social and digital gaming had started to put tremendous pressure on EA’s existing IT infrastructure. He discussed the challenge with millions of micro-transactions coming from several sources – Microsoft Xbox, Paypal, several service providers. EA found Order-2-Cash processes stretched to their limits. They lacked visibility into these transactions across the entire value chain. EA began by consolidating their E-Business Suite R11 instances into single E-Business Suite R12. EA needed to cater to a variety of service requirements, connectivity methods, file formats, and information latency. Their integration strategy was tactical, i.e., using file uploads, TIBCO, SQL scripts. After consolidating E-Business suite, EA standardized their integration approach with Oracle SOA Suite and Oracle AIA Foundation Pack. Oracle SOA Suite is the platform used to extend E-Business Suite R12 and standardize 60+ interfaces across several heterogeneous systems including PeopleSoft, Demantra, SF.com, Workday, and Managed EDI services spanning on-premise, hosted and cloud applications. EA believes that Oracle SOA Suite 11g based extension strategy has helped significantly in the followings ways: - It helped them keep customizations out of E-Business Suite, thereby keeping EBS R12 vanilla and upgrade safe - Developers are now proficient in technology which is also leveraged by Fusion Apps. This has helped them prepare for adoption of Fusion Apps in the future Fig 3: Using Oracle SOA Suite & Oracle e-Business Suite, Electronic Arts built new platform for order processing 3. Consolidate apps and improve scalability Exalogic is an optimal platform for customers to consolidate their application deployments and enhance performance. Underwriter Laboratories talked about their strategy to run their mission critical applications including e-Business Suite on Exalogic. Christian Anschuetz, CIO of Underwriter Laboratories (UL) shared how UL is on a growth path - $1B to $2.5B in 5 years- and planning a significant business transformation from a not-for-profit to a for-profit business. To support this growth, UL is planning to simplify its IT environment and the deployment complexity associated with ERP applications and technology it runs on. Their current applications were deployed on variety of hardware platforms and lacked comprehensive disaster recovery architecture. UL embarked on a mission to deploy E-Business Suite on Exalogic. UL’s solution is unique because it is one of the first to deploy a large number of Oracle applications and related Fusion Middleware technologies (SOA, BI, Analytical Applications AIA Foundation Pack and AIA EBS to Siebel UCM prebuilt integration) on the combined Exalogic and Exadata environment. UL is planning to move to a virtualized architecture toward the end of 2012 to securely host external facing applications like iStore Fig 4: Underwrites Labs deployed e-Business Suite on Exalogic to achieve performance gains Key takeaways are: - Fusion Middleware platform is certified with major Oracle Applications Unlimited offerings. Fusion Middleware is the underlying technological infrastructure for Fusion Apps - Customers choose Oracle Fusion Middleware to extend their applications (Apps Unlimited or Fusion Apps) to keep applications upgrade safe and prepare for Fusion Apps - Exalogic is an optimum platform to consolidate applications deployments and enhance performance TAGS: Fusion Apps, Exalogic, BPM Suite, SOA Suite, e-Business Suite Integration

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  • Amazon Web Services (AWS) Plug-in for Oracle Enterprise Manager

    - by Anand Akela
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Contributed by Sunil Kunisetty and Daniel Chan Introduction and ArchitectureAs more and more enterprises deploy some of their non-critical workload on Amazon Web Services (AWS), it’s becoming critical to monitor those public AWS resources along side with their on-premise resources. Oracle recently announced Oracle Enterprise Manager Plug-in for Amazon Web Services (AWS) allows you to achieve that goal. The on-premise Oracle Enterprise Manager (EM12c) acts as a single tool to get a comprehensive view of your public AWS resources as well as your private cloud resources.  By deploying the plug-in within your Cloud Control environment, you gain the following management features: Monitor EBS, EC2 and RDS instances on Amazon Web Services Gather performance metrics and configuration details for AWS instances Raise alerts and violations based on thresholds set on monitoring Generate reports based on the gathered data Users of this Plug-in can leverage the rich Enterprise Manager features such as system promotion, incident generation based on thresholds, integration with 3rd party ticketing applications etc. AWS Monitoring via this Plug-in is enabled via Amazon CloudWatch API and the users of this Plug-in are responsible for supplying credentials for accessing AWS and the CloudWatch API. This Plug-in can only be deployed on an EM12C R2 platform and agent version should be at minimum 12c R2.Here is a pictorial view of the overall architecture: Amazon Elastic Block Store (EBS) Amazon Elastic Compute Cloud (EC2) Amazon Relational Database Service (RDS) Here are a few key features: Rich and exhaustive list of metrics. Metrics can be gathered from an Agent running outside AWS. Critical configuration information. Custom Home Pages with charts and AWS configuration information. Generate incidents based on thresholds set on monitoring data. Discovery and Monitoring AWS instances can be added to EM12C either via the EM12c User Interface (UI) or the EM12c Command Line Interface ( EMCLI)  by providing the AWS credentials (Secret Key and Access Key Id) as well as resource specific properties as target properties. Here is a quick mapping of target types and properties for each AWS resources AWS Resource Type Target Type Resource specific properties EBS Resource Amazon EBS Service CloudWatch base URI, EC2 Base URI, Period, Volume Id, Proxy Server and Port EC2 Resource Amazon EC2 Service CloudWatch base URI, EC2 Base URI, Period, Instance  Id, Proxy Server and Port RDS Resource Amazon RDS Service CloudWatch base URI, RDS Base URI, Period, Instance  Id, Proxy Server and Port Proxy server and port are optional and are only needed if the agent is within the firewall. Here is an emcli example to add an EC2 target. Please read the Installation and Readme guide for more details and step-by-step instructions to deploy  the plugin and adding the AWS the instances. ./emcli add_target \       -name="<target name>" \       -type="AmazonEC2Service" \       -host="<host>" \       -properties="ProxyHost=<proxy server>;ProxyPort=<proxy port>;EC2_BaseURI=http://ec2.<region>.amazonaws.com;BaseURI=http://monitoring.<region>.amazonaws.com;InstanceId=<EC2 instance Id>;Period=<data point periond>"  \     -subseparator=properties="=" ./emcli set_monitoring_credential \                 -set_name="AWSKeyCredentialSet"  \                 -target_name="<target name>"  \                 -target_type="AmazonEC2Service" \                 -cred_type="AWSKeyCredential"  \                 -attributes="AccessKeyId:<access key id>;SecretKey:<secret key>" Emcli utility is found under the ORACLE_HOME of EM12C install. Once the instance is discovered, the target will show up under the ‘All Targets’ list under “Amazon EC2 Service’. Once the instances are added, one can navigate to the custom homepages for these resource types. The custom home pages not only include critical metrics, but also vital configuration parameters and incidents raised for these instances.  By mapping the configuration parameters as instance properties, we can slice-and-dice and group various AWS instance by leveraging the EM12C Config search feature. The following configuration properties and metrics are collected for these Resource types. Resource Type Configuration Properties Metrics EBS Resource Volume Id, Volume Type, Device Name, Size, Availability Zone Response: Status Utilization: QueueLength, IdleTime Volume Statistics: ReadBrandwith, WriteBandwidth, ReadThroughput, WriteThroughput Operation Statistics: ReadSize, WriteSize, ReadLatency, WriteLatency EC2 Resource Instance ID, Owner Id, Root Device type, Instance Type. Availability Zone Response: Status CPU Utilization: CPU Utilization Disk I/O:  DiskReadBytes, DiskWriteBytes, DiskReadOps, DiskWriteOps, DiskReadRate, DiskWriteRate, DiskIOThroughput, DiskReadOpsRate, DiskWriteOpsRate, DiskOperationThroughput Network I/O : NetworkIn, NetworkOut, NetworkInRate, NetworkOutRate, NetworkThroughput RDS Resource Instance ID, Database Engine Name, Database Engine Version, Database Instance Class, Allocated Storage Size, Availability Zone Response: Status Disk I/O:  ReadIOPS, WriteIOPS, ReadLatency, WriteLatency, ReadThroughput, WriteThroughput DB Utilization:  BinLogDiskUsage, CPUUtilization, DatabaseConnections, FreeableMemory, ReplicaLag, SwapUsage Custom Home Pages As mentioned above, we have custom home pages for these target types that include basic configuration information,  last 24 hours availability, top metrics and the incidents generated. Here are few snapshots. EBS Instance Home Page: EC2 Instance Home Page: RDS Instance Home Page: Further Reading: 1)      AWS Plugin download 2)      Installation and  Read Me. 3)      Screenwatch on SlideShare 4)      Extensibility Programmer's Guide 5)      Amazon Web Services

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  • GoldenGate 12c Trail Encryption and Credentials with Oracle Wallet

    - by hamsun
    I have been asked more than once whether the Oracle Wallet supports GoldenGate trail encryption. Although GoldenGate has supported encryption with the ENCKEYS file for years, Oracle GoldenGate 12c now also supports encryption using the Oracle Wallet. This helps improve security and makes it easier to administer. Two types of wallets can be configured in Oracle GoldenGate 12c: The wallet that holds the master keys, used with trail or TCP/IP encryption and decryption, stored in the new 12c dirwlt/cwallet.sso file.   The wallet that holds the Oracle Database user IDs and passwords stored in the ‘credential store’ stored in the new 12c dircrd/cwallet.sso file.   A wallet can be created using a ‘create wallet’  command.  Adding a master key to an existing wallet is easy using ‘open wallet’ and ‘add masterkey’ commands.   GGSCI (EDLVC3R27P0) 42> open wallet Opened wallet at location 'dirwlt'. GGSCI (EDLVC3R27P0) 43> add masterkey Master key 'OGG_DEFAULT_MASTERKEY' added to wallet at location 'dirwlt'.   Existing GUI Wallet utilities that come with other products such as the Oracle Database “Oracle Wallet Manager” do not work on this version of the wallet. The default Oracle Wallet can be changed.   GGSCI (EDLVC3R27P0) 44> sh ls -ltr ./dirwlt/* -rw-r----- 1 oracle oinstall 685 May 30 05:24 ./dirwlt/cwallet.sso GGSCI (EDLVC3R27P0) 45> info masterkey Masterkey Name:                 OGG_DEFAULT_MASTERKEY Creation Date:                  Fri May 30 05:24:04 2014 Version:        Creation Date:                  Status: 1               Fri May 30 05:24:04 2014        Current   The second wallet file is used for the credential used to connect to a database, without exposing the user id or password. Once it is configured, this file can be copied so that credentials are available to connect to the source or target database.   GGSCI (EDLVC3R27P0) 48> sh cp ./dircrd/cwallet.sso $GG_EURO_HOME/dircrd GGSCI (EDLVC3R27P0) 49> sh ls -ltr ./dircrd/* -rw-r----- 1 oracle oinstall 709 May 28 05:39 ./dircrd/cwallet.sso   The encryption wallet file can also be copied to the target machine so the replicat has access to the master key to decrypt records that are encrypted in the trail. Similar to the old ENCKEYS file, the master keys wallet created on the source host must either be stored in a centrally available disk or copied to all GoldenGate target hosts. The wallet is in a platform-independent format, although it is not certified for the iSeries, z/OS, and NonStop platforms.   GGSCI (EDLVC3R27P0) 50> sh cp ./dirwlt/cwallet.sso $GG_EURO_HOME/dirwlt   The new 12c UserIdAlias parameter is used to locate the credential in the wallet so the source user id and password does not need to be stored as a parameter as long as it is in the wallet.   GGSCI (EDLVC3R27P0) 52> view param extwest extract extwest exttrail ./dirdat/ew useridalias gguamer table west.*; The EncryptTrail parameter is used to encrypt the trail using the Advanced Encryption Standard and can be used with a primary extract or pump extract. GGSCI (EDLVC3R27P0) 54> view param pwest extract pwest encrypttrail AES256 rmthost easthost, mgrport 15001 rmttrail ./dirdat/pe passthru table west.*;   Once the extracts are running, records can be encrypted using the wallet.   GGSCI (EDLVC3R27P0) 60> info extract *west EXTRACT    EXTWEST   Last Started 2014-05-30 05:26   Status RUNNING Checkpoint Lag       00:00:17 (updated 00:00:01 ago) Process ID           24982 Log Read Checkpoint  Oracle Integrated Redo Logs                      2014-05-30 05:25:53                      SCN 0.0 (0) EXTRACT    PWEST     Last Started 2014-05-30 05:26   Status RUNNING Checkpoint Lag       24:02:32 (updated 00:00:05 ago) Process ID           24983 Log Read Checkpoint  File ./dirdat/ew000004                      2014-05-29 05:23:34.748949  RBA 1483   The ‘info masterkey’ command is used to confirm the wallet contains the key after copying it to the target machine. The key is needed to decrypt the data in the trail before the replicat applies the changes to the target database.   GGSCI (EDLVC3R27P0) 41> open wallet Opened wallet at location 'dirwlt'. GGSCI (EDLVC3R27P0) 42> info masterkey Masterkey Name:                 OGG_DEFAULT_MASTERKEY Creation Date:                  Fri May 30 05:24:04 2014 Version:        Creation Date:                  Status: 1               Fri May 30 05:24:04 2014        Current   Once the replicat is running, records can be decrypted using the wallet.   GGSCI (EDLVC3R27P0) 44> info reast REPLICAT   REAST     Last Started 2014-05-30 05:28   Status RUNNING INTEGRATED Checkpoint Lag       00:00:00 (updated 00:00:02 ago) Process ID           25057 Log Read Checkpoint  File ./dirdat/pe000004                      2014-05-30 05:28:16.000000  RBA 1546   There is no need for the DecryptTrail parameter when using the Oracle Wallet, unlike when using the ENCKEYS file.   GGSCI (EDLVC3R27P0) 45> view params reast replicat reast assumetargetdefs discardfile ./dirrpt/reast.dsc, purge useridalias ggueuro map west.*, target east.*;   Once a record is inserted into the source table and committed, the encryption can be verified using logdump and then querying the target table.   AMER_SQL>insert into west.branch values (50, 80071); 1 row created.   AMER_SQL>commit; Commit complete.   The following encrypted record can be found using logdump. Logdump 40 >n 2014/05/30 05:28:30.001.154 Insert               Len    28 RBA 1546 Name: WEST.BRANCH After  Image:                                             Partition 4   G  s    0a3e 1ba3 d924 5c02 eade db3f 61a9 164d 8b53 4331 | .>...$\....?a..M.SC1   554f e65a 5185 0257                               | UO.ZQ..W  Bad compressed block, found length of  7075 (x1ba3), RBA 1546   GGS tokens: TokenID x52 'R' ORAROWID         Info x00  Length   20  4141 4157 7649 4141 4741 4141 4144 7541 4170 0001 | AAAWvIAAGAAAADuAAp..  TokenID x4c 'L' LOGCSN           Info x00  Length    7  3231 3632 3934 33                                 | 2162943  TokenID x36 '6' TRANID           Info x00  Length   10  3130 2e31 372e 3135 3031                          | 10.17.1501  The replicat automatically decrypted this record from the trail and then inserted the row to the target table using the wallet. This select verifies the row was inserted into the target database and the data is not encrypted. EURO_SQL>select * from branch where branch_number=50; BRANCH_NUMBER                  BRANCH_ZIP -------------                                   ----------    50                                              80071   Book a seat in an upcoming Oracle GoldenGate 12c: Fundamentals for Oracle course now to learn more about GoldenGate 12c new features including how to use GoldenGate with the Oracle wallet, credentials, integrated extracts, integrated replicats, the Oracle Universal Installer, and other new features. Looking for another course? View all Oracle GoldenGate training.   Randy Richeson joined Oracle University as a Senior Principal Instructor in March 2005. He is an Oracle Certified Professional (10g-12c) and a GoldenGate Certified Implementation Specialist (10-11g). He has taught GoldenGate since 2010 and also has experience teaching other technical curriculums including GoldenGate Monitor, Veridata, JD Edwards, PeopleSoft, and the Oracle Application Server.

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  • Building KPIs to monitor your business Its not really about the Technology

    When I have discussions with people about Business Intelligence, one of the questions the inevitably come up is about building KPIs and how to accomplish that. From a technical level the concept of a KPI is very simple, almost too simple in that it is like the tip of an iceberg floating above the water. The key to that iceberg is not really the tip, but the mass of the iceberg that is hidden beneath the surface upon which the tip sits. The analogy of the iceberg is not meant to indicate that the foundation of the KPI is overly difficult or complex. The disparity in size in meant to indicate that the larger thing that needs to be defined is not the technical tip, but the underlying business definition of what the KPI means. From a technical perspective the KPI consists of primarily the following items: Actual Value This is the actual value data point that is being measured. An example would be something like the amount of sales. Target Value This is the target goal for the KPI. This is a number that can be measured against Actual Value. An example would be $10,000 in monthly sales. Target Indicator Range This is the definition of ranges that define what type of indicator the user will see comparing the Actual Value to the Target Value. Most often this is defined by stoplight, but can be any indicator that is going to show a status in a quick fashion to the user. Typically this would be something like: Red Light = Actual Value more than 5% below target; Yellow Light = Within 5% of target either direction; Green Light = More than 5% higher than Target Value Status\Trend Indicator This is an optional attribute of a KPI that is typically used to show some kind of trend. The vast majority of these indicators are used to show some type of progress against a previous period. As an example, the status indicator might be used to show how the monthly sales compare to last month. With this type of indicator there needs to be not only a definition of what the ranges are for your status indictor, but then also what value the number needs to be compared against. So now we have an idea of what data points a KPI consists of from a technical perspective lets talk a bit about tools. As you can see technically there is not a whole lot to them and the choice of technology is not as important as the definition of the KPIs, which we will get to in a minute. There are many different types of tools in the Microsoft BI stack that you can use to expose your KPI to the business. These include Performance Point, SharePoint, Excel, and SQL Reporting Services. There are pluses and minuses to each technology and the right technology is based a lot on your goals and how you want to deliver the information to the users. Additionally, there are other non-Microsoft tools that can be used to expose KPI indicators to your business users. Regardless of the technology used as your front end, the heavy lifting of KPI is in the business definition of the values and benchmarks for that KPI. The discussion about KPIs is very dependent on the history of an organization and how much they are exposed to the attributes of a KPI. Often times when discussing KPIs with a business contact who has not been exposed to KPIs the discussion tends to also be a session educating the business user about what a KPI is and what goes into the definition of a KPI. The majority of times the business user has an idea of what their actual values are and they have been tracking those numbers for some time, generally in Excel and all manually. So they will know the amount of sales last month along with sales two years ago in the same month. Where the conversation tends to get stuck is when you start discussing what the target value should be. The actual value is answering the What and How much questions. When you are talking about the Target values you are asking the question Is this number good or bad. Typically, the user will know whether or not the value is good or bad, but most of the time they are not able to quantify what is good or bad. Their response is usually something like I just know. Because they have been watching the sales quantity for years now, they can tell you that a 5% decrease in sales this month might actually be a good thing, maybe because the salespeople are all waiting until next month when the new versions come out. It can sometimes be very hard to break the business people of this habit. One of the fears generally is that the status indicator is not subjective. Thus, in the scenario above, the business user is going to be fearful that their boss, just looking at a negative red indicator, is going to haul them out to the woodshed for a bad month. But, on the flip side, if all you are displaying is the amount of sales, only a person with knowledge of last month sales and the target amount for this month would have any idea if $10,000 in sales is good or not. Here is where a key point about KPIs needs to be communicated to both the business user and any user who might be viewing the results of that KPI. The KPI is just one tool that is used to report on business performance. The KPI is meant as a quick indicator of one business statistic. It is not meant to tell the entire story. It does not answer the question Why. Its primary purpose is to objectively and quickly expose an area of the business that might warrant more review. There is always going to be the need to do further analysis on any potential negative or neutral KPI. So, hopefully, once you have convinced your business user to come up with some target numbers and ranges for status indicators, you then need to take the next step and help them answer the Why question. The main question here to ask is, Okay, you see the indicator and you need to discover why the number is what is, where do you go?. The answer is usually a combination of sources. A sales manager might have some of the following items at their disposal (Marketing report showing a decrease in the promotional discounts for the month, Pricing Report showing the reduction of prices of older models, an Inventory Report showing the discontinuation of a particular product line, or a memo showing the ending of a large affiliate partnership. The answers to the question Why are never as simple as a single indicator value. Bring able to quickly get to this information is all about designing how a user accesses the KPIs and then also how easily they can get to the additional information they need. This is where a Dashboard mentality can come in handy. For example, the business user can have a dashboard that shows their KPIs, but also has links to some of the common reports that they run regarding Sales Data. The users boss may have the same KPIs on their dashboard, but instead of links to individual reports they are going to have a link to a status report that was created by the user that pulls together all the data about the KPI in a summary format the users boss can review. So some of the key things to think about when building or evaluating KPIs for your organization: Technology should not be the driving factor KPIs are of little value without some indicator for whether a value is good, bad or neutral. KPIs only give an answer to the Is this number good\bad? question Make sure the ability to drill into the Why of a KPI is close at hand and relevant to the user who is viewing the KPI. The KPI is a key business tool when defined properly to help monitor business performance across the enterprise in an objective and consistent manner. At times it might feel like the process of defining the business aspects of a KPI can sometimes be arduous, the payoff in the end can far outweigh the costs. Some of the benefits of going through this process are a better understanding of the key metrics for an organization and the measure of those metrics and a consistent snapshot of business performance that can be utilized across the organization. And I think that these are benefits to any organization regardless of the technology or the implementation.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Scrolling an HTML 5 page using JQuery

    - by nikolaosk
    In this post I will show you how to use JQuery to scroll through an HTML 5 page.I had to help a friend of mine to implement this functionality and I thought it would be a good idea to write a post.I will not use any JQuery scrollbar plugin,I will just use the very popular JQuery Library. Please download the library (minified version) from http://jquery.com/download.Please find here all my posts regarding JQuery.Also have a look at my posts regarding HTML 5.In order to be absolutely clear this is not (and could not be) a detailed tutorial on HTML 5. There are other great resources for that.Navigate to the excellent interactive tutorials of W3School.Another excellent resource is HTML 5 Doctor.Two very nice sites that show you what features and specifications are implemented by various browsers and their versions are http://caniuse.com/ and http://html5test.com/. At this times Chrome seems to support most of HTML 5 specifications.Another excellent way to find out if the browser supports HTML 5 and CSS 3 features is to use the Javascript lightweight library Modernizr.In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like.You can use Visual Studio 2012 Express edition. You can download it here. Let me move on to the actual example.This is the sample HTML 5 page<!DOCTYPE html><html lang="en">  <head>    <title>Liverpool Legends</title>        <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >        <link rel="stylesheet" type="text/css" href="style.css">        <script type="text/javascript" src="jquery-1.8.2.min.js"> </script>     <script type="text/javascript" src="scroll.js">     </script>       </head>  <body>    <header>        <h1>Liverpool Legends</h1>    </header>        <div id="main">        <table>        <caption>Liverpool Players</caption>        <thead>            <tr>                <th>Name</th>                <th>Photo</th>                <th>Position</th>                <th>Age</th>                <th>Scroll</th>            </tr>        </thead>        <tfoot class="footnote">            <tr>                <td colspan="4">We will add more photos soon</td>            </tr>        </tfoot>    <tbody>        <tr class="maintop">        <td>Alan Hansen</td>            <td>            <figure>            <img src="images\Alan-hansen-large.jpg" alt="Alan Hansen">            <figcaption>The best Liverpool Defender <a href="http://en.wikipedia.org/wiki/Alan_Hansen">Alan Hansen</a></figcaption>            </figure>            </td>            <td>Defender</td>            <td>57</td>            <td class="top">Middle</td>        </tr>        <tr>        <td>Graeme Souness</td>            <td>            <figure>            <img src="images\graeme-souness-large.jpg" alt="Graeme Souness">            <figcaption>Souness was the captain of the successful Liverpool team of the early 1980s <a href="http://en.wikipedia.org/wiki/Graeme_Souness">Graeme Souness</a></figcaption>            </figure>            </td>            <td>MidFielder</td>            <td>59</td>        </tr>        <tr>        <td>Ian Rush</td>            <td>            <figure>            <img src="images\ian-rush-large.jpg" alt="Ian Rush">            <figcaption>The deadliest Liverpool Striker <a href="http://it.wikipedia.org/wiki/Ian_Rush">Ian Rush</a></figcaption>            </figure>            </td>            <td>Striker</td>            <td>51</td>        </tr>        <tr class="mainmiddle">        <td>John Barnes</td>            <td>            <figure>            <img src="images\john-barnes-large.jpg" alt="John Barnes">            <figcaption>The best Liverpool Defender <a href="http://en.wikipedia.org/wiki/John_Barnes_(footballer)">John Barnes</a></figcaption>            </figure>            </td>            <td>MidFielder</td>            <td>49</td>            <td class="middle">Bottom</td>        </tr>                <tr>        <td>Kenny Dalglish</td>            <td>            <figure>            <img src="images\kenny-dalglish-large.jpg" alt="Kenny Dalglish">            <figcaption>King Kenny <a href="http://en.wikipedia.org/wiki/Kenny_Dalglish">Kenny Dalglish</a></figcaption>            </figure>            </td>            <td>Midfielder</td>            <td>61</td>        </tr>        <tr>            <td>Michael Owen</td>            <td>            <figure>            <img src="images\michael-owen-large.jpg" alt="Michael Owen">            <figcaption>Michael was Liverpool's top goal scorer from 1997–2004 <a href="http://www.michaelowen.com/">Michael Owen</a></figcaption>            </figure>            </td>            <td>Striker</td>            <td>33</td>        </tr>        <tr>            <td>Robbie Fowler</td>            <td>            <figure>            <img src="images\robbie-fowler-large.jpg" alt="Robbie Fowler">            <figcaption>Fowler scored 183 goals in total for Liverpool <a href="http://en.wikipedia.org/wiki/Robbie_Fowler">Robbie Fowler</a></figcaption>            </figure>            </td>            <td>Striker</td>            <td>38</td>        </tr>        <tr class="mainbottom">            <td>Steven Gerrard</td>            <td>            <figure>            <img src="images\steven-gerrard-large.jpg" alt="Steven Gerrard">            <figcaption>Liverpool's captain <a href="http://en.wikipedia.org/wiki/Steven_Gerrard">Steven Gerrard</a></figcaption>            </figure>            </td>            <td>Midfielder</td>            <td>32</td>            <td class="bottom">Top</td>        </tr>    </tbody></table>          </div>            <footer>        <p>All Rights Reserved</p>      </footer>     </body>  </html>  The markup is very easy to follow and understand. You do not have to type all the code,simply copy and paste it.For those that you are not familiar with HTML 5, please take a closer look at the new tags/elements introduced with HTML 5.When I view the HTML 5 page with Firefox I see the following result. I have also an external stylesheet (style.css). body{background-color:#efefef;}h1{font-size:2.3em;}table { border-collapse: collapse;font-family: Futura, Arial, sans-serif; }caption { font-size: 1.2em; margin: 1em auto; }th, td {padding: .65em; }th, thead { background: #000; color: #fff; border: 1px solid #000; }tr:nth-child(odd) { background: #ccc; }tr:nth-child(even) { background: #404040; }td { border-right: 1px solid #777; }table { border: 1px solid #777;  }.top, .middle, .bottom {    cursor: pointer;    font-size: 22px;    font-weight: bold;    text-align: center;}.footnote{text-align:center;font-family:Tahoma;color:#EB7515;}a{color:#22577a;text-decoration:none;}     a:hover {color:#125949; text-decoration:none;}  footer{background-color:#505050;width:1150px;}These are just simple CSS Rules that style the various HTML 5 tags,classes. The jQuery code that makes it all possible resides inside the scroll.js file.Make sure you type everything correctly.$(document).ready(function() {                 $('.top').click(function(){                     $('html, body').animate({                         scrollTop: $(".mainmiddle").offset().top                     },4000 );                  });                 $('.middle').click(function(){                     $('html, body').animate({                         scrollTop: $(".mainbottom").offset().top                     },4000);                  });                     $('.bottom').click(function(){                     $('html, body').animate({                         scrollTop: $(".maintop").offset().top                     },4000);                  }); });  Let me explain what I am doing here.When I click on the Middle word (  $('.top').click(function(){ ) this relates to the top class that is clicked.Then we declare the elements that we want to participate in the scrolling. In this case is html,body ( $('html, body').animate).These elements will be part of the vertical scrolling.In the next line of code we simply move (navigate) to the element (class mainmiddle that is attached to a tr element.)      scrollTop: $(".mainmiddle").offset().top  Make sure you type all the code correctly and try it for yourself. I have tested this solution will all 4-5 major browsers.Hope it helps!!!

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  • Small adventure game

    - by Nick Rosencrantz
    I'm making a small adventure game where the player can walk through Dungeons and meet scary characters: The whole thing is 20 java classes and I'm making this a standalone frame while it could very well be an applet I don't want to make another applet since I might want to recode this in C/C++ if the game or game engine turns out a success. The engine is the most interesting part of the game, it controls players and computer-controlled characters such as Zombies, Reptile Warriors, Trolls, Necromancers, and other Persons. These persons can sleep or walk around in the game and also pick up and move things. I didn't add many things so I suppose that is the next thing to do is to add things that can get used now that I already added many different types of walking persons. What do you think I should add and do with things in the game? The things I have so far is: package adventure; /** * The data type for things. Subclasses will be create that takes part of the story */ public class Thing { /** * The name of the Thing. */ public String name; /** * @param name The name of the Thing. */ Thing( String name ) { this.name = name; } } public class Scroll extends Thing { Scroll (String name) { super(name); } } class Key extends Thing { Key (String name) { super(name); } } The key is the way to win the game if you figure our that you should give it to a certain person and the scroll can protect you from necromancers and trolls. If I make this game more Dungeons and Dragons-inspired, do you think will be any good? Any other ideas that you think I could use here? The Threadwhich steps time forward and wakes up persons is called simulation. Do you think I could do something more advanced with this class? package adventure; class Simulation extends Thread { private PriorityQueue Eventqueue; Simulation() { Eventqueue = new PriorityQueue(); start(); } public void wakeMeAfter(Wakeable SleepingObject, double time) { Eventqueue.enqueue(SleepingObject, System.currentTimeMillis()+time); } public void run() { while(true) { try { sleep(5); //Sov i en halv sekund if (Eventqueue.getFirstTime() <= System.currentTimeMillis()) { ((Wakeable)Eventqueue.getFirst()).wakeup(); Eventqueue.dequeue(); } } catch (InterruptedException e ) { } } } } And here is the class that makes up the actual world: package adventure; import java.awt.*; import java.net.URL; /** * Subklass to World that builds up the Dungeon World. */ public class DungeonWorld extends World { /** * * @param a Reference to adventure game. * */ public DungeonWorld(Adventure a) { super ( a ); // Create all places createPlace( "Himlen" ); createPlace( "Stairs3" ); createPlace( "IPLab" ); createPlace( "Dungeon3" ); createPlace( "Stairs5" ); createPlace( "C2M2" ); createPlace( "SANS" ); createPlace( "Macsal" ); createPlace( "Stairs4" ); createPlace( "Dungeon2" ); createPlace( "Datorsalen" ); createPlace( "Dungeon");//, "Ljushallen.gif" ); createPlace( "Cola-automaten", "ColaAutomat.gif" ); createPlace( "Stairs2" ); createPlace( "Fable1" ); createPlace( "Dungeon1" ); createPlace( "Kulverten" ); // Create all connections between places connect( "Stairs3", "Stairs5", "Down", "Up" ); connect( "Dungeon3", "SANS", "Down", "Up" ); connect( "Dungeon3", "IPLab", "West", "East" ); connect( "IPLab", "Stairs3", "West", "East" ); connect( "Stairs5", "Stairs4", "Down", "Up" ); connect( "Macsal", "Stairs5", "South", "Norr" ); connect( "C2M2", "Stairs5", "West", "East" ); connect( "SANS", "C2M2", "West", "East" ); connect( "Stairs4", "Dungeon", "Down", "Up" ); connect( "Datorsalen", "Stairs4", "South", "Noth" ); connect( "Dungeon2", "Stairs4", "West", "East" ); connect( "Dungeon", "Stairs2", "Down", "Up" ); connect( "Dungeon", "Cola-automaten", "South", "North" ); connect( "Stairs2", "Kulverten", "Down", "Up" ); connect( "Stairs2", "Fable1", "East", "West" ); connect( "Fable1", "Dungeon1", "South", "North" ); // Add things // --- Add new things here --- getPlace("Cola-automaten").addThing(new CocaCola("Ljummen cola")); getPlace("Cola-automaten").addThing(new CocaCola("Avslagen Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Iskall Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Cola Light")); getPlace("Cola-automaten").addThing(new CocaCola("Cuba Cola")); getPlace("Stairs4").addThing(new Scroll("Scroll")); getPlace("Dungeon3").addThing(new Key("Key")); Simulation sim = new Simulation(); // Load images to be used as appearance-parameter for persons Image studAppearance = owner.loadPicture( "Person.gif" ); Image asseAppearance = owner.loadPicture( "Asse.gif" ); Image trollAppearance = owner.loadPicture( "Loke.gif" ); Image necromancerAppearance = owner.loadPicture( "Necromancer.gif" ); Image skeletonAppearance = owner.loadPicture( "Reptilewarrior.gif" ); Image reptileAppearance = owner.loadPicture( "Skeleton.gif" ); Image zombieAppearance = owner.loadPicture( "Zombie.gif" ); // --- Add new persons here --- new WalkingPerson(sim, this, "Peter", studAppearance); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "John", studAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Sean", studAppearance ); new WalkingPerson(sim, this, "Reptile", reptileAppearance ); new LabAssistant(sim, this, "Kate", asseAppearance); new LabAssistant(sim, this, "Jenna", asseAppearance); new Troll(sim, this, "Troll", trollAppearance); new Necromancer(sim, this, "Necromancer", necromancerAppearance); } /** * * The place where persons are placed by default * *@return The default place. * */ public Place defaultPlace() { return getPlace( "Datorsalen" ); } private void connect( String p1, String p2, String door1, String door2) { Place place1 = getPlace( p1 ); Place place2 = getPlace( p2 ); place1.addExit( door1, place2 ); place2.addExit( door2, place1 ); } } Thanks

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  • Connect to running web role on Azure using Remote Desktop Connection and VS2012

    - by Magnus Karlsson
    We want to be able to collect IntelliTrace information from our running app and also use remote desktop to connect to the IIS and look around(probably debugging). 1. Create certificate 1.1 Right-click the cloud project (marked in red) and select “Configure remote desktop”. 1.2 In the drop down list of certificates, choose <create> at the bottom. 1.3. Follow the instructions, you can set it up with default values. 1.4 When done. Choose the certificate and click “Copy to File…” as seen in the left of the picture above. 1.5. Save the file with any name you want. Now we will save it to local storage to be able to import it to our solution through the azure configuration manager in step 3. 2. Save certificate to local storage Now we need to attach it to our local certificate storage to be able to reach it from our confiuguration manager in visual studio. Microsoft provides the following steps for doing this: http://support.microsoft.com/kb/232137 In order to view the Certificates store on the local computer, perform the following steps: Click Start, and then click Run. Type "MMC.EXE" (without the quotation marks) and click OK. Click Console in the new MMC you created, and then click Add/Remove Snap-in. In the new window, click Add. Highlight the Certificates snap-in, and then click Add. Choose the Computer option and click Next. Select Local Computer on the next screen, and then click OK. Click Close , and then click OK. You have now added the Certificates snap-in, which will allow you to work with any certificates in your computer's certificate store. You may want to save this MMC for later use. Now that you have access to the Certificates snap-in, you can import the server certificate into you computer's certificate store by following these steps: Open the Certificates (Local Computer) snap-in and navigate to Personal, and then Certificates. Note: Certificates may not be listed. If it is not, that is because there are no certificates installed. Right-click Certificates (or Personal if that option does not exist.) Choose All Tasks, and then click Import. When the wizard starts, click Next. Browse to the PFX file you created containing your server certificate and private key. Click Next. Enter the password you gave the PFX file when you created it. Be sure the Mark the key as exportable option is selected if you want to be able to export the key pair again from this computer. As an added security measure, you may want to leave this option unchecked to ensure that no one can make a backup of your private key. Click Next, and then choose the Certificate Store you want to save the certificate to. You should select Personal because it is a Web server certificate. If you included the certificates in the certification hierarchy, it will also be added to this store. Click Next. You should see a summary of screen showing what the wizard is about to do. If this information is correct, click Finish. You will now see the server certificate for your Web server in the list of Personal Certificates. It will be denoted by the common name of the server (found in the subject section of the certificate). Now that you have the certificate backup imported into the certificate store, you can enable Internet Information Services 5.0 to use that certificate (and the corresponding private key). To do this, perform the following steps: Open the Internet Services Manager (under Administrative Tools) and navigate to the Web site you want to enable secure communications (SSL/TLS) on. Right-click on the site and click Properties. You should now see the properties screen for the Web site. Click the Directory Security tab. Under the Secure Communications section, click Server Certificate. This will start the Web Site Certificate Wizard. Click Next. Choose the Assign an existing certificate option and click Next. You will now see a screen showing that contents of your computer's personal certificate store. Highlight your Web server certificate (denoted by the common name), and then click Next. You will now see a summary screen showing you all the details about the certificate you are installing. Be sure that this information is correct or you may have problems using SSL or TLS in HTTP communications. Click Next, and then click OK to exit the wizard. You should now have an SSL/TLS-enabled Web server. Be sure to protect your PFX files from any unwanted personnel. Image of a typical MMC.EXE with the certificates up.   3. Import the certificate to you visual studio project. 3.1 Now right click your equivalent to the MvcWebRole1 (as seen in the first picture under the red oval) and choose properties. 3.2 Choose Certificates. Right click the ellipsis to the right of the “thumbprint” and you should be able to select your newly created certificate here. After selecting it- save the file.   4. Upload the certificate to your Azure subscription. 4.1 Go to the azure management portal, click the services menu icon to the left and choose the service. Click Upload in the bottom menu.     5. Connect to server. Since I tried to use account settings(have to use another name) we have to set up a new name for the connection. No biggie. 5.1 Go to azure management portal, select your service and in the bottom menu, choose “REMOTE”. This will display the configuration for remote connection. It will actually change your ServiceConfiguration.cscfg file. After you change It here it might be good to choose download and replace the one in your project. Set a name that is not your windows azure account name and not Administrator. 5.2 Goto visual studio, click Server Explorer. Choose as selected in the picture below and click “COnnect using remote desktop”.   5.2 You will now be able to log in with the name and password set up in step 5.1. and voila! Windows server 2012, IIS and other nice stuff!   To do this one I’ve been using http://msdn.microsoft.com/en-us/library/windowsazure/ff683671.aspx where you can collect some of this information and additional one.

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 2 – Table per Type (TPT)

    - by mortezam
    In the previous blog post you saw that there are three different approaches to representing an inheritance hierarchy and I explained Table per Hierarchy (TPH) as the default mapping strategy in EF Code First. We argued that the disadvantages of TPH may be too serious for our design since it results in denormalized schemas that can become a major burden in the long run. In today’s blog post we are going to learn about Table per Type (TPT) as another inheritance mapping strategy and we'll see that TPT doesn’t expose us to this problem. Table per Type (TPT)Table per Type is about representing inheritance relationships as relational foreign key associations. Every class/subclass that declares persistent properties—including abstract classes—has its own table. The table for subclasses contains columns only for each noninherited property (each property declared by the subclass itself) along with a primary key that is also a foreign key of the base class table. This approach is shown in the following figure: For example, if an instance of the CreditCard subclass is made persistent, the values of properties declared by the BillingDetail base class are persisted to a new row of the BillingDetails table. Only the values of properties declared by the subclass (i.e. CreditCard) are persisted to a new row of the CreditCards table. The two rows are linked together by their shared primary key value. Later, the subclass instance may be retrieved from the database by joining the subclass table with the base class table. TPT Advantages The primary advantage of this strategy is that the SQL schema is normalized. In addition, schema evolution is straightforward (modifying the base class or adding a new subclass is just a matter of modify/add one table). Integrity constraint definition are also straightforward (note how CardType in CreditCards table is now a non-nullable column). Another much more important advantage is the ability to handle polymorphic associations (a polymorphic association is an association to a base class, hence to all classes in the hierarchy with dynamic resolution of the concrete class at runtime). A polymorphic association to a particular subclass may be represented as a foreign key referencing the table of that particular subclass. Implement TPT in EF Code First We can create a TPT mapping simply by placing Table attribute on the subclasses to specify the mapped table name (Table attribute is a new data annotation and has been added to System.ComponentModel.DataAnnotations namespace in CTP5): public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } [Table("BankAccounts")] public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } } [Table("CreditCards")] public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; } } If you prefer fluent API, then you can create a TPT mapping by using ToTable() method: protected override void OnModelCreating(ModelBuilder modelBuilder) {     modelBuilder.Entity<BankAccount>().ToTable("BankAccounts");     modelBuilder.Entity<CreditCard>().ToTable("CreditCards"); } Generated SQL For QueriesLet’s take an example of a simple non-polymorphic query that returns a list of all the BankAccounts: var query = from b in context.BillingDetails.OfType<BankAccount>() select b; Executing this query (by invoking ToList() method) results in the following SQL statements being sent to the database (on the bottom, you can also see the result of executing the generated query in SQL Server Management Studio): Now, let’s take an example of a very simple polymorphic query that requests all the BillingDetails which includes both BankAccount and CreditCard types: projects some properties out of the base class BillingDetail, without querying for anything from any of the subclasses: var query = from b in context.BillingDetails             select new { b.BillingDetailId, b.Number, b.Owner }; -- var query = from b in context.BillingDetails select b; This LINQ query seems even more simple than the previous one but the resulting SQL query is not as simple as you might expect: -- As you can see, EF Code First relies on an INNER JOIN to detect the existence (or absence) of rows in the subclass tables CreditCards and BankAccounts so it can determine the concrete subclass for a particular row of the BillingDetails table. Also the SQL CASE statements that you see in the beginning of the query is just to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type) TPT ConsiderationsEven though this mapping strategy is deceptively simple, the experience shows that performance can be unacceptable for complex class hierarchies because queries always require a join across many tables. In addition, this mapping strategy is more difficult to implement by hand— even ad-hoc reporting is more complex. This is an important consideration if you plan to use handwritten SQL in your application (For ad hoc reporting, database views provide a way to offset the complexity of the TPT strategy. A view may be used to transform the table-per-type model into the much simpler table-per-hierarchy model.) SummaryIn this post we learned about Table per Type as the second inheritance mapping in our series. So far, the strategies we’ve discussed require extra consideration with regard to the SQL schema (e.g. in TPT, foreign keys are needed). This situation changes with the Table per Concrete Type (TPC) that we will discuss in the next post. References ADO.NET team blog Java Persistence with Hibernate book a { text-decoration: none; } a:visited { color: Blue; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } p.MsoNormal { margin-top: 0in; margin-right: 0in; margin-bottom: 10.0pt; margin-left: 0in; line-height: 115%; font-size: 11.0pt; font-family: "Calibri" , "sans-serif"; }

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  • Mobile Friendly Websites with CSS Media Queries

    - by dwahlin
    In a previous post the concept of CSS media queries was introduced and I discussed the fundamentals of how they can be used to target different screen sizes. I showed how they could be used to convert a 3-column wide page into a more vertical view of data that displays better on devices such as an iPhone:     In this post I'll provide an additional look at how CSS media queries can be used to mobile-enable a sample site called "Widget Masters" without having to change any server-side code or HTML code. The site that will be discussed is shown next:     This site has some of the standard items shown in most websites today including a title area, menu bar, and sections where data is displayed. Without including CSS media queries the site is readable but has to be zoomed out to see everything on a mobile device, cuts-off some of the menu items, and requires horizontal scrolling to get to additional content. The following image shows what the site looks like on an iPhone. While the site works on mobile devices it's definitely not optimized for mobile.     Let's take a look at how CSS media queries can be used to override existing styles in the site based on different screen widths. Adding CSS Media Queries into a Site The Widget Masters Website relies on standard CSS combined with HTML5 elements to provide the layout shown earlier. For example, to layout the menu bar shown at the top of the page the nav element is used as shown next. A standard div element could certainly be used as well if desired.   <nav> <ul class="clearfix"> <li><a href="#home">Home</a></li> <li><a href="#products">Products</a></li> <li><a href="#aboutus">About Us</a></li> <li><a href="#contactus">Contact Us</a></li> <li><a href="#store">Store</a></li> </ul> </nav>   This HTML is combined with the CSS shown next to add a CSS3 gradient, handle the horizontal orientation, and add some general hover effects.   nav { width: 100%; } nav ul { border-radius: 6px; height: 40px; width: 100%; margin: 0; padding: 0; background: rgb(125,126,125); /* Old browsers */ background: -moz-linear-gradient(top, rgba(125,126,125,1) 0%, rgba(14,14,14,1) 100%); /* FF3.6+ */ background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(125,126,125,1)), color-stop(100%,rgba(14,14,14,1))); /* Chrome,Safari4+ */ background: -webkit-linear-gradient(top, rgba(125,126,125,1) 0%, rgba(14,14,14,1) 100%); /* Chrome10+,Safari5.1+ */ background: -o-linear-gradient(top, rgba(125,126,125,1) 0%, rgba(14,14,14,1) 100%); /* Opera 11.10+ */ background: -ms-linear-gradient(top, rgba(125,126,125,1) 0%, rgba(14,14,14,1) 100%); /* IE10+ */ background: linear-gradient(top, rgba(125,126,125,1) 0%, rgba(14,14,14,1) 100%); /* W3C */ filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#7d7e7d', endColorstr='#0e0e0e',GradientType=0 ); /* IE6-9 */ } nav ul > li { list-style: none; float: left; margin: 0; padding: 0; } nav ul > li:first-child { margin-left: 8px; } nav ul > li > a { color: #ccc; text-decoration: none; line-height: 2.8em; font-size: 0.95em; font-weight: bold; padding: 8px 25px 7px 25px; font-family: Arial, Helvetica, sans-serif; } nav ul > li a:hover { background-color: rgba(0, 0, 0, 0.1); color: #fff; }   When mobile devices hit the site the layout of the menu items needs to be adjusted so that they're all visible without having to swipe left or right to get to them. This type of modification can be accomplished using CSS media queries by targeting specific screen sizes. To start, a media query can be added into the site's CSS file as shown next: @media screen and (max-width:320px) { /* CSS style overrides for this screen width go here */ } This media query targets screens that have a maximum width of 320 pixels. Additional types of queries can also be added – refer to my previous post for more details as well as resources that can be used to test media queries in different devices. In that post I emphasize (and I'll emphasize again) that CSS media queries only modify the overall layout and look and feel of a site. They don't optimize the site as far as the size of the images or content sent to the device which is important to keep in mind. To make the navigation menu more accessible on devices such as an iPhone or Android the CSS shown next can be used. This code changes the height of the menu from 40 pixels to 100%, takes off the li element floats, changes the line-height, and changes the margins.   @media screen and (max-width:320px) { nav ul { height: 100%; } nav ul > li { float: none; } nav ul > li a { line-height: 1.5em; } nav ul > li:first-child { margin-left: 0px; } /* Additional CSS overrides go here */ }   The following image shows an example of what the menu look like when run on a device with a width of 320 pixels:   Mobile devices with a maximum width of 480 pixels need different CSS styles applied since they have 160 additional pixels of width. This can be done by adding a new CSS media query into the stylesheet as shown next. Looking through the CSS you'll see that only a minimal override is added to adjust the padding of anchor tags since the menu fits by default in this screen width.   @media screen and (max-width: 480px) { nav ul > li > a { padding: 8px 10px 7px 10px; } }   Running the site on a device with 480 pixels results in the menu shown next being rendered. Notice that the space between the menu items is much smaller compared to what was shown when the main site loads in a standard browser.     In addition to modifying the menu, the 3 horizontal content sections shown earlier can be changed from a horizontal layout to a vertical layout so that they look good on a variety of smaller mobile devices and are easier to navigate by end users. The HTML5 article and section elements are used as containers for the 3 sections in the site as shown next:   <article class="clearfix"> <section id="info"> <header>Why Choose Us?</header> <br /> <img id="mainImage" src="Images/ArticleImage.png" title="Article Image" /> <p> Post emensos insuperabilis expeditionis eventus languentibus partium animis, quas periculorum varietas fregerat et laborum, nondum tubarum cessante clangore vel milite locato per stationes hibernas. </p> </section> <section id="products"> <header>Products</header> <br /> <img id="gearsImage" src="Images/Gears.png" title="Article Image" /> <p> <ul> <li>Widget 1</li> <li>Widget 2</li> <li>Widget 3</li> <li>Widget 4</li> <li>Widget 5</li> </ul> </p> </section> <section id="FAQ"> <header>FAQ</header> <br /> <img id="faqImage" src="Images/faq.png" title="Article Image" /> <p> <ul> <li>FAQ 1</li> <li>FAQ 2</li> <li>FAQ 3</li> <li>FAQ 4</li> <li>FAQ 5</li> </ul> </p> </section> </article>   To force the sections into a vertical layout for smaller mobile devices the CSS styles shown next can be added into the media queries targeting 320 pixel and 480 pixel widths. Styles to target the display size of the images in each section are also included. It's important to note that the original image is still being downloaded from the server and isn't being optimized in any way for the mobile device. It's certainly possible for the CSS to include URL information for a mobile-optimized image if desired. @media screen and (max-width:320px) { section { float: none; width: 97%; margin: 0px; padding: 5px; } #wrapper { padding: 5px; width: 96%; } #mainImage, #gearsImage, #faqImage { width: 100%; height: 100px; } } @media screen and (max-width: 480px) { section { float: none; width: 98%; margin: 0px 0px 10px 0px; padding: 5px; } article > section:last-child { margin-right: 0px; float: none; } #bottomSection { width: 99%; } #wrapper { padding: 5px; width: 96%; } #mainImage, #gearsImage, #faqImage { width: 100%; height: 100px; } }   The following images show the site rendered on an iPhone with the CSS media queries in place. Each of the sections now displays vertically making it much easier for the user to access them. Images inside of each section also scale appropriately to fit properly.     CSS media queries provide a great way to override default styles in a website and target devices with different resolutions. In this post you've seen how CSS media queries can be used to convert a standard browser-based site into a site that is more accessible to mobile users. Although much more can be done to optimize sites for mobile, CSS media queries provide a nice starting point if you don't have the time or resources to create mobile-specific versions of sites.

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  • Using HTML 5 SessionState to save rendered Page Content

    - by Rick Strahl
    HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which  is a simple, string based key value store that has getItem, setItem, removeitem, clear and  key methods. The objects are also pseudo array objects and so can be iterated like an array with  a length property and you have array indexers to set and get values with. Basic usage  for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab:   You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile  (or browse the base url with your browser width under 800px)   Here's what the mobile, non-frames view looks like:   As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings"  entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering  as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds  the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a  full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using  AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript  HTML5  ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Create excel files with GemBox.Spreadsheet .NET component

    - by hajan
    Generating excel files from .NET code is not always a very easy task, especially if you need to make some formatting or you want to do something very specific that requires extra coding. I’ve recently tried the GemBox Spreadsheet and I would like to share my experience with you. First of all, you can install GemBox Spreadsheet library from VS.NET 2010 Extension manager by searching in the gallery: Go in the Online Gallery tab (as in the picture bellow) and write GemBox in the Search box on top-right of the Extension Manager, so you will get the following result: Click Download on GemBox.Spreadsheet and you will be directed to product website. Click on the marked link then you will get to the following page where you have the component download link Once you download it, install the MSI file. Open the installation folder and find the Bin folder. There you have GemBox.Spreadsheet.dll in three folders each for different .NET Framework version. Now, lets move to Visual Studio.NET. 1. Create sample ASP.NET Web Application and give it a name. 2. Reference The GemBox.Spreadsheet.dll file in your project So you don’t need to search for the dll file in your disk but you can simply find it in the .NET tab in ‘Add Reference’ window and you have all three versions. I chose the version for 4.0.30319 runtime. Next, I will retrieve data from my Pubs database. I’m using Entity Framework. Here is the code (read the comments in it):             //get data from pubs database, tables: authors, titleauthor, titles             pubsEntities context = new pubsEntities();             var authorTitles = (from a in context.authors                                join tl in context.titleauthor on a.au_id equals tl.au_id                                join t in context.titles on tl.title_id equals t.title_id                                select new AuthorTitles                                {                                     Name = a.au_fname,                                     Surname = a.au_lname,                                     Title = t.title,                                     Price = t.price,                                     PubDate = t.pubdate                                }).ToList();             //using GemBox library now             ExcelFile myExcelFile = new ExcelFile();             ExcelWorksheet excWsheet = myExcelFile.Worksheets.Add("Hajan's worksheet");             excWsheet.Cells[0, 0].Value = "Pubs database Authors and Titles";             excWsheet.Cells[0, 0].Style.Borders.SetBorders(MultipleBorders.Bottom,System.Drawing.Color.Red,LineStyle.Thin);             excWsheet.Cells[0, 1].Style.Borders.SetBorders(MultipleBorders.Bottom, System.Drawing.Color.Red, LineStyle.Thin);                                      int numberOfColumns = 5; //the number of properties in the authorTitles we have             //for each column             for (int c = 0; c < numberOfColumns; c++)             {                 excWsheet.Columns[c].Width = 25 * 256; //set the width to each column                             }             //header row cells             excWsheet.Rows[2].Cells[0].Value = "Name";             excWsheet.Rows[2].Cells[1].Value = "Surname";             excWsheet.Rows[2].Cells[2].Value = "Title";             excWsheet.Rows[2].Cells[3].Value = "Price";             excWsheet.Rows[2].Cells[4].Value = "PubDate";             //bind authorTitles in the excel worksheet             int currentRow = 3;             foreach (AuthorTitles at in authorTitles)             {                 excWsheet.Rows[currentRow].Cells[0].Value = at.Name;                 excWsheet.Rows[currentRow].Cells[1].Value = at.Surname;                 excWsheet.Rows[currentRow].Cells[2].Value = at.Title;                 excWsheet.Rows[currentRow].Cells[3].Value = at.Price;                 excWsheet.Rows[currentRow].Cells[4].Value = at.PubDate;                 currentRow++;             }             //stylizing my excel file look             CellStyle style = new CellStyle(myExcelFile);             style.HorizontalAlignment = HorizontalAlignmentStyle.Left;             style.VerticalAlignment = VerticalAlignmentStyle.Center;             style.Font.Color = System.Drawing.Color.DarkRed;             style.WrapText = true;             style.Borders.SetBorders(MultipleBorders.Top                 | MultipleBorders.Left | MultipleBorders.Right                 | MultipleBorders.Bottom, System.Drawing.Color.Black,                 LineStyle.Thin);                                 //pay attention on this, we set created style on the given (firstRow, firstColumn, lastRow, lastColumn)             //in my example:             //firstRow = 2; firstColumn = 0; lastRow = authorTitles.Count+1; lastColumn = numberOfColumns-1; variable             excWsheet.Cells.GetSubrangeAbsolute(3, 0, authorTitles.Count+2, numberOfColumns-1).Style = style;             //save my excel file             myExcelFile.SaveXls(Server.MapPath(".") + @"/myFile.xls"); The AuthorTitles class: public class AuthorTitles {     public string Name { get; set; }     public string Surname { get; set; }     public string Title { get; set; }     public decimal? Price { get; set; }     public DateTime PubDate { get; set; } } The excel file will be generated in the root of your ASP.NET Web Application. The result is: There is a lot more you can do with this library. A set of good examples you have in the GemBox.Spreadsheet Samples Explorer application which comes together with the installation and you can find it by default in Start –> All Programs –> GemBox Software –> GemBox.Spreadsheet Samples Explorer. Hope this was useful for you. Best Regards, Hajan

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  • Minecraft Style Chunk building problem

    - by David Torrey
    I'm having some problems with speed in my chunk engine. I timed it out, and in its current state it takes a total ~5 seconds per chunk to fill each face's list. I have a check to see if each face of a block is visible and if it is not visible, it skips it and moves on. I'm using a dictionary (unordered map) because it makes sense memorywise to just not have an entry if there is no block. I've tracked my problem down to testing if there is an entry, and accessing an entry if it does exist. If I remove the tests to see if there is an entry in the dictionary for an adjacent block, or if the block type itself is seethrough, it runs within about 2-4 milliseconds. so here's my question: Is there a faster way to check for an entry in a dictionary than .ContainsKey()? As an aside, I tried TryGetValue() and it doesn't really help with the speed that much. If I remove the ContainsKey() and keep the test where it does the IsSeeThrough for each block, it halves the time, but it's still about 2-3 seconds. It only drops to 2-4ms if I remove BOTH checks. Here is my code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Runtime.InteropServices; using OpenTK; using OpenTK.Graphics.OpenGL; using System.Drawing; namespace Anabelle_Lee { public enum BlockEnum { air = 0, dirt = 1, } [StructLayout(LayoutKind.Sequential,Pack=1)] public struct Coordinates<T1> { public T1 x; public T1 y; public T1 z; public override string ToString() { return "(" + x + "," + y + "," + z + ") : " + typeof(T1); } } public struct Sides<T1> { public T1 left; public T1 right; public T1 top; public T1 bottom; public T1 front; public T1 back; } public class Block { public int blockType; public bool SeeThrough() { switch (blockType) { case 0: return true; } return false ; } public override string ToString() { return ((BlockEnum)(blockType)).ToString(); } } class Chunk { private Dictionary<Coordinates<byte>, Block> mChunkData; //stores the block data private Sides<List<Coordinates<byte>>> mVBOVertexBuffer; private Sides<int> mVBOHandle; //private bool mIsChanged; private const byte mCHUNKSIZE = 16; public Chunk() { } public void InitializeChunk() { //create VBO references #if DEBUG Console.WriteLine ("Initializing Chunk"); #endif mChunkData = new Dictionary<Coordinates<byte> , Block>(); //mIsChanged = true; GL.GenBuffers(1, out mVBOHandle.left); GL.GenBuffers(1, out mVBOHandle.right); GL.GenBuffers(1, out mVBOHandle.top); GL.GenBuffers(1, out mVBOHandle.bottom); GL.GenBuffers(1, out mVBOHandle.front); GL.GenBuffers(1, out mVBOHandle.back); //make new list of vertexes for each face mVBOVertexBuffer.top = new List<Coordinates<byte>>(); mVBOVertexBuffer.bottom = new List<Coordinates<byte>>(); mVBOVertexBuffer.left = new List<Coordinates<byte>>(); mVBOVertexBuffer.right = new List<Coordinates<byte>>(); mVBOVertexBuffer.front = new List<Coordinates<byte>>(); mVBOVertexBuffer.back = new List<Coordinates<byte>>(); #if DEBUG Console.WriteLine("Chunk Initialized"); #endif } public void GenerateChunk() { #if DEBUG Console.WriteLine("Generating Chunk"); #endif for (byte i = 0; i < mCHUNKSIZE; i++) { for (byte j = 0; j < mCHUNKSIZE; j++) { for (byte k = 0; k < mCHUNKSIZE; k++) { Random blockLoc = new Random(); Coordinates<byte> randChunk = new Coordinates<byte> { x = i, y = j, z = k }; mChunkData.Add(randChunk, new Block()); mChunkData[randChunk].blockType = blockLoc.Next(0, 1); } } } #if DEBUG Console.WriteLine("Chunk Generated"); #endif } public void DeleteChunk() { //delete VBO references #if DEBUG Console.WriteLine("Deleting Chunk"); #endif GL.DeleteBuffers(1, ref mVBOHandle.left); GL.DeleteBuffers(1, ref mVBOHandle.right); GL.DeleteBuffers(1, ref mVBOHandle.top); GL.DeleteBuffers(1, ref mVBOHandle.bottom); GL.DeleteBuffers(1, ref mVBOHandle.front); GL.DeleteBuffers(1, ref mVBOHandle.back); //clear all vertex buffers ClearPolyLists(); #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void UpdateChunk() { #if DEBUG Console.WriteLine("Updating Chunk"); #endif ClearPolyLists(); //prepare buffers //for every entry in mChunkData map foreach(KeyValuePair<Coordinates<byte>,Block> feBlockData in mChunkData) { Coordinates<byte> checkBlock = new Coordinates<byte> { x = feBlockData.Key.x, y = feBlockData.Key.y, z = feBlockData.Key.z }; //check for polygonson the left side of the cube if (checkBlock.x > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x - 1, checkBlock.y, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.left); } //check for polygons on the right side of the cube if (checkBlock.x < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x + 1, checkBlock.y, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.right); } if (checkBlock.y > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y - 1, checkBlock.z)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.bottom); } //check for polygons on the right side of the cube if (checkBlock.y < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y + 1, checkBlock.z)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.top); } if (checkBlock.z > 0) { //check to see if there is a key for current x - 1. if not, add the vector if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z - 1)) { //add polygon AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } } else { //polygon is far left and should be added AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.back); } //check for polygons on the right side of the cube if (checkBlock.z < mCHUNKSIZE - 1) { if (!IsVisible(checkBlock.x, checkBlock.y, checkBlock.z + 1)) { //add poly AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } else { //poly for right add AddPoly(checkBlock.x, checkBlock.y, checkBlock.z, mVBOHandle.front); } } BuildBuffers(); #if DEBUG Console.WriteLine("Chunk Updated"); #endif } public void RenderChunk() { } public void LoadChunk() { #if DEBUG Console.WriteLine("Loading Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Deleted"); #endif } public void SaveChunk() { #if DEBUG Console.WriteLine("Saving Chunk"); #endif #if DEBUG Console.WriteLine("Chunk Saved"); #endif } private bool IsVisible(int pX,int pY,int pZ) { Block testBlock; Coordinates<byte> checkBlock = new Coordinates<byte> { x = Convert.ToByte(pX), y = Convert.ToByte(pY), z = Convert.ToByte(pZ) }; if (mChunkData.TryGetValue(checkBlock,out testBlock )) //if data exists { if (testBlock.SeeThrough() == true) //if existing data is not seethrough { return true; } } return true; } private void AddPoly(byte pX, byte pY, byte pZ, int BufferSide) { //create temp array GL.BindBuffer(BufferTarget.ArrayBuffer, BufferSide); if (BufferSide == mVBOHandle.front) { //front face mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.front.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.right) { //back face mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.back.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.top) { //left face mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.left.Add(new Coordinates<byte> { x = (byte)(pX), y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.bottom) { //right face mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ + 1) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY) , z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.right.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); } else if (BufferSide == mVBOHandle.front) { //top face mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ + 1) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY + 1), z = (byte)(pZ) }); mVBOVertexBuffer.top.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY + 1), z = (byte)(pZ) }); } else if (BufferSide == mVBOHandle.back) { //bottom face mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX + 1), y = (byte)(pY), z = (byte)(pZ + 1) }); mVBOVertexBuffer.bottom.Add(new Coordinates<byte> { x = (byte)(pX) , y = (byte)(pY), z = (byte)(pZ + 1) }); } } private void BuildBuffers() { #if DEBUG Console.WriteLine("Building Chunk Buffers"); #endif GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.front); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.front.Count), mVBOVertexBuffer.front.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.back); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.back.Count), mVBOVertexBuffer.back.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.left); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.left.Count), mVBOVertexBuffer.left.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.right); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.right.Count), mVBOVertexBuffer.right.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.top); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.top.Count), mVBOVertexBuffer.top.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer, mVBOHandle.bottom); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Marshal.SizeOf(new Coordinates<byte>()) * mVBOVertexBuffer.bottom.Count), mVBOVertexBuffer.bottom.ToArray(), BufferUsageHint.StaticDraw); GL.BindBuffer(BufferTarget.ArrayBuffer,0); #if DEBUG Console.WriteLine("Chunk Buffers Built"); #endif } private void ClearPolyLists() { #if DEBUG Console.WriteLine("Clearing Polygon Lists"); #endif mVBOVertexBuffer.top.Clear(); mVBOVertexBuffer.bottom.Clear(); mVBOVertexBuffer.left.Clear(); mVBOVertexBuffer.right.Clear(); mVBOVertexBuffer.front.Clear(); mVBOVertexBuffer.back.Clear(); #if DEBUG Console.WriteLine("Polygon Lists Cleared"); #endif } }//END CLASS }//END NAMESPACE

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  • BING Search using ASP.NET and jQuery Ajax

    - by hajan
    The BING API provides extremely simple way to make search queries using BING. It provides nice way to get the search results as XML or JSON. In this blog post I will show one simple example on how to query BING and get the results as JSON in an ASP.NET website with help of jQuery’s getJSON ajax method. Basically we submit an HTTP GET request with the AppID which you can get in the BING Developer Center. To create new AppID, click here. Once you fill the form, submit it and you will get your AppID. Now, lets make this work in several steps. 1. Open VS.NET or Visual Web Developer.NET, create new sample project (or use existing one) and create new ASPX Web Form with name of your choice. 2. Add the following ASPX in your page body <body>     <form id="form1" runat="server">     <asp:TextBox ID="txtSearch" runat="server" /> <asp:Button ID="btnSearch" runat="server" Text="BING Search" />     <div id="result">          </div>     </form> </body> We have text box for search, button for firing the search event and div where we will place the results. 3. Next, I have created simple CSS style for the search result: <style type="text/css">             .item { width:600px; padding-top:10px; }             .title { background-color:#4196CE; color:White; font-size:18px;              font-family:Calibri, Verdana, Tahoma, Sans-Serif; padding:2px 2px 2px 2px; }     .title a { text-decoration:none; color:white}     .date { font-style:italic; font-size:10px; font-family:Verdana, Arial, Sans-Serif;}             .description { font-family:Verdana, Arial, Sans-Serif; padding:2px 2px 2px 2px; font-size:12px; }     .url { font-size: 10px; font-style:italic; font-weight:bold; color:Gray;}     .url a { text-decoration:none; color:gray;}     #txtSearch { width:450px; border:2px solid #4196CE; } </style> 4. The needed jQuery Scripts (v1.4.4 core jQuery and jQuery template plugin) <script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.4.4.min.js" type="text/javascript"></script> <script src="http://ajax.aspnetcdn.com/ajax/jquery.templates/beta1/jquery.tmpl.min.js" type="text/javascript"></script> Note: I use jQuery Templates plugin in order to avoid foreach loop in the jQuery callback function. JQuery Templates also simplifies the code and allows us to create nice template for the end result. You can read more about jQuery Templates here. 5. Now, lets create another script tag where we will write our BING search script <script language="javascript" type="text/javascript">     $(document).ready(function () {         var bingAPIKey = "<Your-BING-AppID-KEY-HERE>";                  //the rest of the script goes here              }); </script> 6. Before we do any searching, we need to take a look at the search URL that we will call from our Ajax function BING Search URL : http://api.search.live.net/json.aspx?JsonType=callback&JsonCallback=?&AppId={appId}&query={query}&sources={sourceType} The URL in our example is as follows: http://api.search.live.net/json.aspx?JsonType=callback&JsonCallback=?&Appid=" + bingAPIKey + "&query=" + keyWords + "&sources=web Lets split it up with brief explanation on each part of the URL http://api.search.live.net/json.aspx – is the main part of the URL which is used to call when we need to retrieve json result set. JsonType=callback&JsonCallback=? – using JsonType, we can control the format of the response. For more info about this, refer here. Appid=” + bingAPIKey +” – the AppID we’ve got from the BING website, explained previously query=” + keyWords + “ – the search query keywords sources=web – the type of source. Possible source types can be found here. 7. Before we continue with writing the last part of the script, lets see what search result BING will send us back: {"SearchResponse":     {         "Version":"2.2",         "Query":             {                 "SearchTerms":"hajan selmani aspnet weblog"             },         "Web":             {                 "Total":16,                 "Offset":0,                 "Results":[                     {                         "Title":"Hajan's Blog",                         "Description":"microsoft asp.net development blog ... Create nice animation on your ASP.NET Menu control using jQuery by hajan",                         "Url":"http:\/\/weblogs.asp.net\/hajan\/",                         "CacheUrl":"http:\/\/cc.bingj.com\/cache.aspx?q=hajan+selmani+aspnet+weblog&d=4760941354158132&w=c9535fb0,d1d66baa",                         "DisplayUrl":"weblogs.asp.net\/hajan",                         "DateTime":"2011-03-03T18:24:00Z"                     },                     {                         "Title":"codeasp.net",                         "Description":"... social community for ASP.NET bloggers - we are one of                                         the largest ASP.NET blog ... 2\/5\/2011 1:41:00 AM by Hajan Selmani - Comments ...",                         "Url":"http:\/\/codeasp.net\/blogs\/hajan",                         "CacheUrl":"http:\/\/cc.bingj.com\/cache.aspx?q=hajan+selmani+aspnet+weblog&d=4826710187311653&w=5b41c930,676a37f8",                         "DisplayUrl":"codeasp.net\/blogs\/hajan",                         "DateTime":"2011-03-03T07:40:00Z"                     }                     ...                         ]             }     } }  To get to the result of the search response, the path is: SearchResponse.Web.Results, where we have array of objects returned back from BING. 8. The final part of the code that performs the search is $("#<%= btnSearch.ClientID %>").click(function (event) {     event.preventDefault();     var keyWords = $("#<%= txtSearch.ClientID %>").val();     var encodedKeyWords = encodeURIComponent(keyWords);     //alert(keyWords);     var url = "http://api.search.live.net/json.aspx?JsonType=callback&JsonCallback=?&Appid="+ bingAPIKey              + "&query=" + encodedKeyWords              + "&sources=web";     $.getJSON(url, function (data) {         $("#result").html("");         $("#bingSearchTemplate").tmpl(data.SearchResponse.Web.Results).appendTo("#result");     }); }); The search happens once we click the Search Button with id btnSearch. We get the keywords from the Text Box with id txtSearch and then we use encodeURIComponent. The encodeURIComponent is used to encode the special characters such as: , / ? : @ & = + $ #, which might be part of the search query string. Then we construct the URL and call it using HTTP GET. The callback function returns the data, where we first clear the html inside div with id result and after that we render the data.SearchResponse.Web.Results array of objects using template with id bingSearchTemplate and append the result into div with id result. 9. The bingSearchTemplate Template <script id="bingSearchTemplate" type="text/html">     <div class="item">         <div class="title"><a href="${Url}" target="_blank">${Title}</a></div>         <div class="date">${DateTime}</div>         <div class="searchresult">             <div class="description">             ${Description}             </div>             <div class="url">                 <a href="${Url}" target="_blank">${Url}</a>             </div>         </div>     </div> </script> If you paid attention on the search result structure that BING creates for us, you have seen properties like Url, Title, Description, DateTime etc. In the above defined template, you see the same wrapped into template tags. Some are combined to create hyperlinked URLs. 10. THE END RESULT   As you see, it’s quite simple to use BING API and make search queries with ASP.NET and jQuery. In addition, if you want to make instant search, replace this line: $(“#<%= btnSearch.ClientID %>”).click(function(event) {        event.preventDefault(); with $(“#<%= txtSearch.ClientID %>”).keyup(function() { This will trigger search on each key up in your keyboard, so if you use this approach, you won’t event need a search button. If it’s your first time working with BING API, it’s very recommended to read the following API Basics PDF document. Hope this was helpful blog post for you.

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  • jQuery Templates - {Supported Tags}

    - by hajan
    I have started with Introduction to jQuery Templates, then jQuery Templates - tmpl(), template() and tmplItem() functions. In this blog we will see what supported tags are available in the jQuery Templates plugin.Template tags can be used inside template together in combination with HTML tags and plain text, which helps to iterate over JSON data. Up to now, there are several supported tags in jQuery Templates plugin: ${expr} or {{= expr}} {{each itemArray}} … {{/each}} {{if condition}} … {{else}} … {{/if}} {{html …}} {{tmpl …}} {{wrap …}} … {{/wrap}}   - ${expr} or {{= expr}} Is used for insertion of data values in the rendered template. It can evaluate fields, functions or expression. Example: <script id="attendeesTemplate" type="text/html">     <li> ${Name} {{= Surname}} </li>         </script> Either ${Name} or {{= Surname}} (with blank space between =<blankspace>Field) will work.   - {{each itemArray}} … {{/each}} each is everywhere the same "(for)each", used to loop over array or collection Example: <script id="attendeesTemplate" type="text/html">     <li>         ${Name} ${Surname}         {{if speaker}}             (<font color="red">speaks</font>)         {{else}}             (attendee)         {{/if}}                 {{each phones}}                             <br />             ${$index}: <em>${$value}</em>         {{/each}}             </li> </script> So, you see we can use ${$index} and ${$value} to get the current index and value while iterating over the item collection. Alternatively, you can add index,value on the following way: {{each(i,v) phones}}     <br />     ${i}: <em>${v}</em> {{/each}} Result would be: Here is complete working example that you can run and see the result: <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">     <title>Nesting and Looping Example :: jQuery Templates</title>     <script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.4.4.min.js" type="text/javascript"></script>     <script src="http://ajax.aspnetcdn.com/ajax/jquery.templates/beta1/jquery.tmpl.js" type="text/javascript"></script>     <script language="javascript" type="text/javascript">         $(function () {             var attendees = [                 { Name: "Hajan", Surname: "Selmani", speaker: true, phones:[070555555, 071888999, 071222333] },                 { Name: "Someone", Surname: "Surname", phones: [070555555, 071222333] },                 { Name: "Third", Surname: "Thirdsurname", phones: [070555555, 071888999, 071222333] },             ];             $("#attendeesTemplate").tmpl(attendees).appendTo("#attendeesList");         });     </script>     <script id="attendeesTemplate" type="text/html">         <li>             ${Name} ${Surname}             {{if speaker}}                 (<font color="red">speaks</font>)             {{else}}                 (attendee)             {{/if}}                     {{each(i,v) phones}}                 <br />                 ${i}: <em>${v}</em>             {{/each}}                 </li>     </script> </head> <body>     <ol id="attendeesList"></ol>     </body> </html>   - {{if condition}} … {{else}} … {{/if}} Standard if/else statement. Of course, you can use it without the {{else}} if you have such condition to check, however closing the {{/if}} tag is required. Example: {{if speaker}}     (<font color="red">speaks</font>) {{else}}     (attendee) {{/if}} You have this same code block in the above complete example showing the 'each' cycle ;).   - {{html …}} Is used for insertion of HTML markup strings in the rendered template. Evaluates the specified field on the current data item, or the specified JavaScript function or expression. Example: - without {{html …}} <script language="javascript" type="text/javascript">   $(function () {   var attendees = [             { Name: "Hajan", Surname: "Selmani", Info: "He <font color='red'>is the speaker of today's</font> session", speaker: true },         ];   $("#myTemplate").tmpl(attendees).appendTo("#speakers"); }); </script> <script id="myTemplate" type="text/html">     ${Name} ${Surname} <br />     ${Info} </script> Result: - with {{html …}} <script language="javascript" type="text/javascript">   $(function () {   var attendees = [             { Name: "Hajan", Surname: "Selmani", Info: "He <font color='red'>is the speaker of today's</font> session", speaker: true },         ];   $("#myTemplate").tmpl(attendees).appendTo("#speakers"); }); </script> <script id="myTemplate" type="text/html">     ${Name} ${Surname} <br />     {{html Info}} </script> Result:   - {{wrap …}} It’s used for composition and incorporation of wrapped HTML. It’s similar to {{tmpl}} Example: <script id="myTmpl" type="text/html">     <div id="personInfo">     <br />     ${Name} ${Surname}     {{wrap "#myWrapper"}}         <h2>${Info}</h2>         <div>             {{if speaker}}                 (speaker)             {{else}}                 (attendee)             {{/if}}         </div>     {{/wrap}}     </div> </script> <script id="myWrapper" type="text/html">     <table><tbody>         <tr>             {{each $item.html("div")}}                 <td>                     {{html $value}}                 </td>             {{/each}}         </tr>     </tbody></table> </script> All the HTMl content inside the {{wrap}} … {{/wrap}} is available to the $item.html(filter, textOnly) method. In our example, we have defined some standard template and created wrapper which calls the other template with id myWrapper. Then using $item.html(“div”) we find the div tag and render the html value (together with the div tag) inside the <td> … </td>. So, here inside td the <div> <speaker or attendee depending of the condition> </div>  will be rendered. The HTML output from this is:   - {{tmpl …}} Used for composition as template items Example: <script id="myTemplate" type="text/html">     <div id="bookItem">         <div id="bookCover">             {{tmpl "#bookCoverTemplate"}}         </div>         <div id="bookDetails">             <div id="book">                             ${title} - ${author}             </div>             <div id="price">$${price}</div>             <div id="Details">${pages} pgs. - ${year} year</div>         </div>     </div> </script> <script id="bookCoverTemplate" type="text/html">     <img src="${image}" alt="${title} Image" /> </script> In this example, using {{tmpl “#bookCoverTemplate”}} I’m calling another template inside the first template. In the other template I’ve created template for a book cover. The rendered HTML of this is: and   So we have seen example for each of the tags that are right now available in the jQuery Templates (beta) plugin which is created by Microsoft as a contribution to the open source jQuery Project. I hope this was useful blog post for you. Regards, HajanNEXT - jQuery Templates with ASP.NET MVC

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  • Inside the Concurrent Collections: ConcurrentDictionary

    - by Simon Cooper
    Using locks to implement a thread-safe collection is rather like using a sledgehammer - unsubtle, easy to understand, and tends to make any other tool redundant. Unlike the previous two collections I looked at, ConcurrentStack and ConcurrentQueue, ConcurrentDictionary uses locks quite heavily. However, it is careful to wield locks only where necessary to ensure that concurrency is maximised. This will, by necessity, be a higher-level look than my other posts in this series, as there is quite a lot of code and logic in ConcurrentDictionary. Therefore, I do recommend that you have ConcurrentDictionary open in a decompiler to have a look at all the details that I skip over. The problem with locks There's several things to bear in mind when using locks, as encapsulated by the lock keyword in C# and the System.Threading.Monitor class in .NET (if you're unsure as to what lock does in C#, I briefly covered it in my first post in the series): Locks block threads The most obvious problem is that threads waiting on a lock can't do any work at all. No preparatory work, no 'optimistic' work like in ConcurrentQueue and ConcurrentStack, nothing. It sits there, waiting to be unblocked. This is bad if you're trying to maximise concurrency. Locks are slow Whereas most of the methods on the Interlocked class can be compiled down to a single CPU instruction, ensuring atomicity at the hardware level, taking out a lock requires some heavy lifting by the CLR and the operating system. There's quite a bit of work required to take out a lock, block other threads, and wake them up again. If locks are used heavily, this impacts performance. Deadlocks When using locks there's always the possibility of a deadlock - two threads, each holding a lock, each trying to aquire the other's lock. Fortunately, this can be avoided with careful programming and structured lock-taking, as we'll see. So, it's important to minimise where locks are used to maximise the concurrency and performance of the collection. Implementation As you might expect, ConcurrentDictionary is similar in basic implementation to the non-concurrent Dictionary, which I studied in a previous post. I'll be using some concepts introduced there, so I recommend you have a quick read of it. So, if you were implementing a thread-safe dictionary, what would you do? The naive implementation is to simply have a single lock around all methods accessing the dictionary. This would work, but doesn't allow much concurrency. Fortunately, the bucketing used by Dictionary allows a simple but effective improvement to this - one lock per bucket. This allows different threads modifying different buckets to do so in parallel. Any thread making changes to the contents of a bucket takes the lock for that bucket, ensuring those changes are thread-safe. The method that maps each bucket to a lock is the GetBucketAndLockNo method: private void GetBucketAndLockNo( int hashcode, out int bucketNo, out int lockNo, int bucketCount) { // the bucket number is the hashcode (without the initial sign bit) // modulo the number of buckets bucketNo = (hashcode & 0x7fffffff) % bucketCount; // and the lock number is the bucket number modulo the number of locks lockNo = bucketNo % m_locks.Length; } However, this does require some changes to how the buckets are implemented. The 'implicit' linked list within a single backing array used by the non-concurrent Dictionary adds a dependency between separate buckets, as every bucket uses the same backing array. Instead, ConcurrentDictionary uses a strict linked list on each bucket: This ensures that each bucket is entirely separate from all other buckets; adding or removing an item from a bucket is independent to any changes to other buckets. Modifying the dictionary All the operations on the dictionary follow the same basic pattern: void AlterBucket(TKey key, ...) { int bucketNo, lockNo; 1: GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, m_buckets.Length); 2: lock (m_locks[lockNo]) { 3: Node headNode = m_buckets[bucketNo]; 4: Mutate the node linked list as appropriate } } For example, when adding another entry to the dictionary, you would iterate through the linked list to check whether the key exists already, and add the new entry as the head node. When removing items, you would find the entry to remove (if it exists), and remove the node from the linked list. Adding, updating, and removing items all follow this pattern. Performance issues There is a problem we have to address at this point. If the number of buckets in the dictionary is fixed in the constructor, then the performance will degrade from O(1) to O(n) when a large number of items are added to the dictionary. As more and more items get added to the linked lists in each bucket, the lookup operations will spend most of their time traversing a linear linked list. To fix this, the buckets array has to be resized once the number of items in each bucket has gone over a certain limit. (In ConcurrentDictionary this limit is when the size of the largest bucket is greater than the number of buckets for each lock. This check is done at the end of the TryAddInternal method.) Resizing the bucket array and re-hashing everything affects every bucket in the collection. Therefore, this operation needs to take out every lock in the collection. Taking out mutiple locks at once inevitably summons the spectre of the deadlock; two threads each hold a lock, and each trying to acquire the other lock. How can we eliminate this? Simple - ensure that threads never try to 'swap' locks in this fashion. When taking out multiple locks, always take them out in the same order, and always take out all the locks you need before starting to release them. In ConcurrentDictionary, this is controlled by the AcquireLocks, AcquireAllLocks and ReleaseLocks methods. Locks are always taken out and released in the order they are in the m_locks array, and locks are all released right at the end of the method in a finally block. At this point, it's worth pointing out that the locks array is never re-assigned, even when the buckets array is increased in size. The number of locks is fixed in the constructor by the concurrencyLevel parameter. This simplifies programming the locks; you don't have to check if the locks array has changed or been re-assigned before taking out a lock object. And you can be sure that when a thread takes out a lock, another thread isn't going to re-assign the lock array. This would create a new series of lock objects, thus allowing another thread to ignore the existing locks (and any threads controlling them), breaking thread-safety. Consequences of growing the array Just because we're using locks doesn't mean that race conditions aren't a problem. We can see this by looking at the GrowTable method. The operation of this method can be boiled down to: private void GrowTable(Node[] buckets) { try { 1: Acquire first lock in the locks array // this causes any other thread trying to take out // all the locks to block because the first lock in the array // is always the one taken out first // check if another thread has already resized the buckets array // while we were waiting to acquire the first lock 2: if (buckets != m_buckets) return; 3: Calculate the new size of the backing array 4: Node[] array = new array[size]; 5: Acquire all the remaining locks 6: Re-hash the contents of the existing buckets into array 7: m_buckets = array; } finally { 8: Release all locks } } As you can see, there's already a check for a race condition at step 2, for the case when the GrowTable method is called twice in quick succession on two separate threads. One will successfully resize the buckets array (blocking the second in the meantime), when the second thread is unblocked it'll see that the array has already been resized & exit without doing anything. There is another case we need to consider; looking back at the AlterBucket method above, consider the following situation: Thread 1 calls AlterBucket; step 1 is executed to get the bucket and lock numbers. Thread 2 calls GrowTable and executes steps 1-5; thread 1 is blocked when it tries to take out the lock in step 2. Thread 2 re-hashes everything, re-assigns the buckets array, and releases all the locks (steps 6-8). Thread 1 is unblocked and continues executing, but the calculated bucket and lock numbers are no longer valid. Between calculating the correct bucket and lock number and taking out the lock, another thread has changed where everything is. Not exactly thread-safe. Well, a similar problem was solved in ConcurrentStack and ConcurrentQueue by storing a local copy of the state, doing the necessary calculations, then checking if that state is still valid. We can use a similar idea here: void AlterBucket(TKey key, ...) { while (true) { Node[] buckets = m_buckets; int bucketNo, lockNo; GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, buckets.Length); lock (m_locks[lockNo]) { // if the state has changed, go back to the start if (buckets != m_buckets) continue; Node headNode = m_buckets[bucketNo]; Mutate the node linked list as appropriate } break; } } TryGetValue and GetEnumerator And so, finally, we get onto TryGetValue and GetEnumerator. I've left these to the end because, well, they don't actually use any locks. How can this be? Whenever you change a bucket, you need to take out the corresponding lock, yes? Indeed you do. However, it is important to note that TryGetValue and GetEnumerator don't actually change anything. Just as immutable objects are, by definition, thread-safe, read-only operations don't need to take out a lock because they don't change anything. All lockless methods can happily iterate through the buckets and linked lists without worrying about locking anything. However, this does put restrictions on how the other methods operate. Because there could be another thread in the middle of reading the dictionary at any time (even if a lock is taken out), the dictionary has to be in a valid state at all times. Every change to state has to be made visible to other threads in a single atomic operation (all relevant variables are marked volatile to help with this). This restriction ensures that whatever the reading threads are doing, they never read the dictionary in an invalid state (eg items that should be in the collection temporarily removed from the linked list, or reading a node that has had it's key & value removed before the node itself has been removed from the linked list). Fortunately, all the operations needed to change the dictionary can be done in that way. Bucket resizes are made visible when the new array is assigned back to the m_buckets variable. Any additions or modifications to a node are done by creating a new node, then splicing it into the existing list using a single variable assignment. Node removals are simply done by re-assigning the node's m_next pointer. Because the dictionary can be changed by another thread during execution of the lockless methods, the GetEnumerator method is liable to return dirty reads - changes made to the dictionary after GetEnumerator was called, but before the enumeration got to that point in the dictionary. It's worth listing at this point which methods are lockless, and which take out all the locks in the dictionary to ensure they get a consistent view of the dictionary: Lockless: TryGetValue GetEnumerator The indexer getter ContainsKey Takes out every lock (lockfull?): Count IsEmpty Keys Values CopyTo ToArray Concurrent principles That covers the overall implementation of ConcurrentDictionary. I haven't even begun to scratch the surface of this sophisticated collection. That I leave to you. However, we've looked at enough to be able to extract some useful principles for concurrent programming: Partitioning When using locks, the work is partitioned into independant chunks, each with its own lock. Each partition can then be modified concurrently to other partitions. Ordered lock-taking When a method does need to control the entire collection, locks are taken and released in a fixed order to prevent deadlocks. Lockless reads Read operations that don't care about dirty reads don't take out any lock; the rest of the collection is implemented so that any reading thread always has a consistent view of the collection. That leads us to the final collection in this little series - ConcurrentBag. Lacking a non-concurrent analogy, it is quite different to any other collection in the class libraries. Prepare your thinking hats!

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