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  • 11g R2 RAC Expert ????????? ~Blog??????~

    - by user763243
    ?????????????????5?????????????????????????????????????????????????????????????????????????????????????????????30??????????????6??????8?????????????????????????????????????????????????????????????????????????????????????????????????????????????????Blog?????????? ??????????????????????????????????????(500?)?RAC?????????????????????????????????????????????????????????? http://oracletech.jp/seminar/event/000557.html ??????????????RAC??????????????????????????????????????????????????????????????????Oracle ??????·??????????2???????????????????Grid Infrastructure 11g R2: ????&ASM??? ???????????????????Oracle ??????·???????????????????????????????????????????????5???????????? ??????Activate?????????????????????????????Activate?????????? Oracle ??????·????????????????????????????????????????????!

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  • Game engine deployment strategy for the Android?

    - by Jeremy Bell
    In college, my senior project was to create a simple 2D game engine complete with a scripting language which compiled to bytecode, which was interpreted. For fun, I'd like to port the engine to android. I'm new to android development, so I'm not sure which way to go as far as deploying the engine on the phone. The easiest way I suppose would be to require the engine/interpreter to be bundled with every game that uses it. This solves any versioning issues. There are two problems with this. One: this makes each game app larger and two: I originally released the engine under the LGPL license (unfortunately), but this deployment strategy makes it difficult to conform to the rules of that license, particularly with respect to allowing users to replace the lib easily with another version. So, my other option is to somehow have the engine stand alone as an Activity or service that somehow responds to intents raised by game apps, and somehow give the engine app permissions to read the scripts and other assets to "run" the game. The user could then be able to replace the engine app with a different version (possibly one they made themselves). Is this even possible? What would you recommend? How could I handle it in a secure way?

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  • Google App Engine application instance recycling and response times...

    - by Konrad
    Hi, I posted this on GAE for Java group, but I hope to get some answers here quicker :) I decided to do some long-run performance tests on my application. I created some small client hitting app every 5-30 minutes and I run 3-5 of threads with such client. I noticed huge differenced in response times and started to investigate issue. I found reason very quick. I am experiencing same issues as described in following topics: Uneven response time between connection to server to first byte sent Application instances seem to be too aggressively recycled Getting 'Request was aborted after waiting too long to attempt to service your request.' after application idle I am using Springframework, it tkes around 18-20s to start app instance, which is causing response times to take from 1s (when requests hits running app - very rare) to 22s when fresh application is created. Is there any solution for this? I was thinking about creating most basic servlet performing critical tasks (serving API call) and leave UI as is. But then I would loose all benefits of Springframework. Is there any solution for this? After solving (hacking) numerous constrains of App Engine which I hit while developing my app that is the one I think will make me move out of App Engine... that's simply to much to all the time think how to win with GAE problems than how to solve my application problems... Any help? Regards Konrad

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  • Can I compare a template variable to an integer in App Engine templates?

    - by matt b
    Using Django templates in Google App Engine (on Python), is it possible to compare a template variable to an integer in an {% if %} block? views.py: class MyHandler(webapp.RequestHandler): def get(self): foo_list = db.GqlQuery(...) ... template_values['foos'] = foo_list template_values['foo_count'] = len(foo_list) handler.response.out.write(template.render(...)) My template: {% if foo_count == 1 %} There is one foo. {% endif %} This blows up with 'if' statement improperly formatted. What I was attempting to do in my template was build a simple if/elif/else tree to be grammatically correct to be able to state #foo_count == 0: There are no foos. #foo_count == 1: There is one foo. #else: There are {{ foos|length }} foos. Browsing the Django template documents (this link provided in the GAE documentation appears to be for versions of Django far newer than what is supported on GAE), it appears as if I can only actually use boolean operators (if in fact boolean operators are supported in this older version of Django) with strings or other template variables. Is it not possible to compare variables to integers or non-strings with Django templates? I'm sure there is an easy way to workaround this - built up the message string on the Python side rather than within the template - but this seems like such a simple operation you ought to be able to handle in a template. It sounds like I should be switching to a more advanced templating engine, but as I am new to Django (templates or any part of it), I'd just like some confirmation first.

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  • Can I compare a template variable to an integer in Django/App Engine templates?

    - by matt b
    Using Django templates in Google App Engine (on Python), is it possible to compare a template variable to an integer in an {% if %} block? views.py: class MyHandler(webapp.RequestHandler): def get(self): foo_list = db.GqlQuery(...) ... template_values['foos'] = foo_list template_values['foo_count'] = len(foo_list) handler.response.out.write(template.render(...)) My template: {% if foo_count == 1 %} There is one foo. {% endif %} This blows up with 'if' statement improperly formatted. What I was attempting to do in my template was build a simple if/elif/else tree to be grammatically correct to be able to state #foo_count == 0: There are no foos. #foo_count == 1: There is one foo. #else: There are {{ foos|length }} foos. Browsing the Django template documents (this link provided in the GAE documentation appears to be for versions of Django far newer than what is supported on GAE), it appears as if I can only actually use boolean operators (if in fact boolean operators are supported in this older version of Django) with strings or other template variables. Is it not possible to compare variables to integers or non-strings with Django templates? I'm sure there is an easy way to workaround this - built up the message string on the Python side rather than within the template - but this seems like such a simple operation you ought to be able to handle in a template. It sounds like I should be switching to a more advanced templating engine, but as I am new to Django (templates or any part of it), I'd just like some confirmation first.

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  • Welcome To The Nashorn Blog

    - by jlaskey
    Welcome to all.  Time to break the ice and instantiate The Nashorn Blog.  I hope to contribute routinely, but we are very busy, at this point, preparing for the next development milestone and, of course, getting ready for open source. So, if there are long gaps between postings please forgive. We're just coming back from JavaOne and are stoked by the positive response to all the Nashorn sessions. It was great for the team to have the front and centre slide from Georges Saab early in the keynote. It seems we have support coming from all directions. Most of the session videos are posted. Check out the links. Nashorn: Optimizing JavaScript and Dynamic Language Execution on the JVM. Unfortunately, Marcus - the code generation juggernaut,  got saddled with the first session of the first day. Still, he had a decent turnout. The talk focused on issues relating to optimizations we did to get good performance from the JVM. Much yet to be done but looking good. Nashorn: JavaScript on the JVM. This was the main talk about Nashorn. I delivered the little bit of this and a little bit of that session with an overview, a follow up on the open source announcement, a run through a few of the Nashorn features and some demos. The room was SRO, about 250±. High points: Sam Pullara, from Twitter, came forward to describe how painless it was to get Mustache.js up and running (20x over Rhino), and,  John Ceccarelli, from NetBeans came forward to describe how Nashorn has become an integral part of Netbeans. A healthy Q & A at the end was very encouraging. Meet the Nashorn JavaScript Team. Michel, Attila, Marcus and myself hosted a Q & A. There was only a handful of people in the room (we assume it was because of a conflicting session ;-) .) Most of the questions centred around Node.jar, which leads me to believe, Nashorn + Node.jar is what has the most interest. Akhil, Mr. Node.jar, sitting in the audience, fielded the Node.jar questions. Nashorn, Node, and Java Persistence. Doug Clarke, Akhil and myself, discussed the title topics, followed by a lengthy Q & A (security had to hustle us out.) 80 or so in the room. Lots of questions about Node.jar. It was great to see Doug's use of Nashorn + JPA. Nashorn in action, with such elegance and grace. Putting the Metaobject Protocol to Work: Nashorn’s Java Bindings. Attila discussed how he applied Dynalink to Nashorn. Good turn out for this session as well. I have a feeling that once people discover and embrace this hidden gem, great things will happen for all languages running on the JVM. Finally, there were quite a few JavaOne sessions that focused on non-Java languages and their impact on the JVM. I've always believed that one's tool belt should carry a variety of programming languages, not just for domain/task applicability, but also to enhance your thinking and approaches to problem solving. For the most part, future blog entries will focus on 'how to' in Nashorn, but if you have any suggestions for topics you want discussed, please drop a line.  Cheers. 

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  • Blogging tips for SQL Server professionals

    - by jamiet
    For some time now I have been intending to put some material together relating my blogging experiences since I began blogging in 2004 and that led to me submitting a session for SQLBits recently where I intended to do just that. That didn’t get enough votes to allow me to present however so instead I resolved to write a blog post about it and Simon Sabin’s recent post Blogging – how do you do it? has prompted me to get around to completing it. So, here I present a compendium of tips that I’ve picked up from authoring a fair few blog posts over the past 6 years. Feedburner Feedburner.com is a service that can consume your blog’s default RSS feed and provide another, replacement, feed that has exactly the same content. You can then supply that replacement feed on your blog site for other people to consume in their RSS readers. Why would you want to do this? Well, two reasons actually: It makes your blog portable. If you ever want to move your blog to a different URL you don’t have to tell your subscribers to move to a different feed. The feedburner feed is a pointer to your blog content rather than being a copy of it. Feedburner will collect stats telling you how many people are subscribed to your feed, which RSS readers they use, stuff like that. Here’s a sample screenshot for http://sqlblog.com/blogs/jamie_thomson/: It also tells you what your most viewed posts are: Web stats like these are notoriously inaccurate but then again the method of measurement here is not important, what IS important is that it gives you a trustworthy ranking of your blog posts and (in my opinion) knowing which are your most popular posts is more important than knowing exactly how many views each post has had. This is just the tip of the iceberg of what Feedburner provides and I recommend every new blogger to try it! Monitor subscribers using Google Reader If for some reason Feedburner is not to your taste or (more likely) you already have an established RSS feed that you do not want to change then Google provide another way in which you can monitor your readership in the shape of their online RSS reader, Google Reader. It provides, for every RSS feed, a collection of stats including the number of Google Reader users that have subscribed to that RSS feed. This is really valuable information and in fact I have been recording this statistic for mine and a number of other blogs for a few years now and as such I can produce the following chart that indicates how readership is trending for those blogs over time: [Good news for my fellow SQLBlog bloggers.] As Stephen Few readily points out, its not the numbers that are important but the trend. Search Engine Optimisation (SEO) SEO (or “How do I get my blog to show up in Google”) is a massive area of expertise which I don’t want (and am unable) to cover in much detail here but there are some simple rules of thumb that will help: Tags – If your blog engine offers the ability to add tags to your blog post, use them. Invariably those tags go into the meta section of the page HTML and search engines lap that stuff up. For example, from my recent post Microsoft publish Visual Studio 2010 Database Project Guidance: Title – Search engines take notice of web page titles as well so make them specific and descriptive (e.g. “Configuring dtsConfig connection strings”) rather than esoteric and meaningless in a vain attempt to be humorous (e.g. “Last night a DJ saved my ETL batch”)! Title(2) – Make your title even more search engine friendly by mentioning high level subject areas, not dissimilar to Twitter hashtags. For example, if you look at all of my posts related to SSIS you will notice that nearly all contain the word “SSIS” in the title even if I had to shoehorn it in there by putting it in square brackets or similar. Another tip, if you ARE putting words into your titles in this artificial manner then put them at the end so that they’re not that prominent in search engine results; they’re there for the search engines to consume, not for human beings. Images – Always add titles and alternate text (ALT attribute) to images in your blog post. If you use Windows 7 or Windows Vista then you can use Live Writer (which Simon recommended) makes this easy for you. Headings – If you want to highlight section headings use heading tags (e.g. <H1>, <H2>, <H3> etc…) rather than just formatting the text appropriately – again, Live makes this easy. These tags give your blog posts structure that is understood by search engines and RSS readers alike. (I believe it makes them more amenable to CSS as well – though that’s not something I know too much about). If you check the HTML source for the blog post you’re reading right now you’ll be able to scan through and see where I have used heading tags. Microsoft provide a free tool called the SEO Toolkit that will analyse your blog site (for free) and tell you what things you should change to improve SEO. Go read more and download for free at Search Engine Optimization Toolkit. Did I mention that it was free? Miscellaneous Tips If you are including code in your blog post then ensure it is formatted correctly. Use SQL Server Central’s T-SQL prettifier for formatting T-SQL code. Use images and videos. Personally speaking there’s nothing I like less when reading a blog than paragraph after paragraph of text. Images make your blog more appealing which means people are more likely to read what you have written. Be original. Don’t plagiarise other people’s content and don’t simply rewrite the contents of Books Online. Every time you publish a blog post tweet a link to it. Include hashtags in your tweet that are more likely to grab people’s attention. That’s probably enough for now - I hope this blog post proves useful to someone out there. If you would appreciate a related session at a forthcoming SQLBits conference then please let me know. This will likely be my last blog post for 2010 so I would like to take this opportunity to thank everyone that has commented on, linked to or read any of my blog posts in that time. 2011 is shaping up to be a very interesting for SQL Server observers with the impending release of SQL Server code-named Denali and I promise I’ll have lots more content on that as the year progresses. Happy New Year. @Jamiet

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  • Where to start with game development?

    - by steven_desu
    Searching for related questions I found a number of very specific questions, but I'm afraid the specifics have proved fruitless for me and after 4 hours on Google I'm no closer than I started, so I felt reaching out to a community might be in order. First, my goal: I've never made a game before, although I've muddled over the possibility several times. I decided to finally sit down and start learning how to code games, use game engines, etc. All so that one day (hopefully soon) I'll be able to make functional (albeit simple) games. I can start adding complexity later, for now I'd be glad to have a keyboard-controlled camera moving in a 3D world with no interaction beyond that. My background: I've worked in SEVERAL programming languages ranging from PHP to C++ to Java to ASM. I'm not afraid of any challenges that come with learning the new syntax or limitations inherent in a new language. All of my past programming experience, however, has been strictly non-graphical and usually with little or extremely simple interaction during execution. I've created extensive and brilliant algorithms for solving logical and mathematical problems. However in every case input was either defined in a file, passed form an HTML form, or typed into the console. Real-time interaction with the user is something with which I have no experience. My question: Where should I start in trying to make games? Better yet- where should I start in trying to create a keyboard-navigable 3D environment? In searching online I've found several resources linking to game engines, graphics engines, and physics engines. Here's a brief summary of my experiences with a few engines I tried: Unreal SDK: The tutorial videos assume that you already have in-depth knowledge of 3D modeling, graphics engines, animations, etc. The "Getting Started" page offers no formal explanation of game development but jumps into how Unreal can streamline processes it assumes you're already familiar with. After downloading the SDK and launching it to see if the tools were as intuitive as they claimed, I was greeted with about 60 buttons and a blank void for my 3D modeling. Clicking on "add volume" (to attempt to add a basic cube) I was met with a menu of 30 options. Panicking, I closed the editor. Crystal Space: The website seemed rather informative, explaining that Crystal Space was just for graphics and the companion software, CEL, provided entity logic for making games. A demo game was provided, which was built using "CELStart", their simple tool for people with no knowledge of game programming. I launched the game to see what I might look forward to creating. It froze several times, the menus were buggy, there were thousands of graphical glitches, enemies didn't respond to damage, and when I closed the game it locked up. Gave up on that engine. IrrLicht: The tutorial assumes I have Visual Studio 6.0 (I have Visual Studio 2010). Following their instructions I was unable to properly import the library into Visual Studio and unable to call any of the functions that they kept using. Manually copying header files, class files, and DLLs into my project's folder - the project failed to properly compile. Clearly I'm not off to a good start and I'm going in circles. Can someone point me in the right direction? Should I start by downloading a program like Blender and learning 3D modeling, or should I be learning how to use a graphics engine? Should I look for an all-inclusive game engine, or is it better to try and code my own game logic? If anyone has actually made their own games, I would prefer to hear how they got their start. Also- taking classes at my school is not an option. Nothing is offered.

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  • C++ property system interface for game editors (reflection system)

    - by Cristopher Ismael Sosa Abarca
    I have designed an reusable game engine for an project, and their functionality is like this: Is a completely scripted game engine instead of the usual scripting languages as Lua or Python, this uses Runtime-Compiled C++, and an modified version of Cistron (an component-based programming framework).to be compatible with Runtime-Compiled C++ and so on. Using the typical GameObject and Component classes of the Component-based design pattern, is serializable via JSON, BSON or Binary useful for selecting which objects will be loaded the next time. The main problem: We want to use our custom GameObjects and their components properties in our level editor, before used hardcoded functions to access GameObject base class virtual functions from the derived ones, if do you want to modify an property specifically from that class you need inside into the code, this situation happens too with the derived classes of Component class, in little projects there's no problem but for larger projects becomes tedious, lengthy and error-prone. I've researched a lot to find a solution without luck, i tried with the Ogitor's property system (since our engine is Ogre-based) but we find it inappropiate for the component-based design and it's limited only for the Ogre classes and can lead to performance overhead, and we tried some code we find in the Internet we tested it and worked a little but we considered the macro and lambda abuse too horrible take a look (some code omitted): IWE_IMPLEMENT_PROP_BEGIN(CBaseEntity) IWE_PROP_LEVEL_BEGIN("Editor"); IWE_PROP_INT_S("Id", "Internal id", m_nEntID, [](int n) {}, true); IWE_PROP_LEVEL_END(); IWE_PROP_LEVEL_BEGIN("Entity"); IWE_PROP_STRING_S("Mesh", "Mesh used for this entity", m_pModelName, [pInst](const std::string& sModelName) { pInst->m_stackMemUndoType.push(ENT_MEM_MESH); pInst->m_stackMemUndoStr.push(pInst->getModelName()); pInst->setModel(sModelName, false); pInst->saveState(); }, false); IWE_PROP_VECTOR3_S("Position", m_vecPosition, [pInst](float fX, float fY, float fZ) { pInst->m_stackMemUndoType.push(ENT_MEM_POSITION); pInst->m_stackMemUndoVec3.push(pInst->getPosition()); pInst->saveState(); pInst->m_vecPosition.Get()[0] = fX; pInst->m_vecPosition.Get()[1] = fY; pInst->m_vecPosition.Get()[2] = fZ; pInst->setPosition(pInst->m_vecPosition); }, false); IWE_PROP_QUATERNION_S("Orientation (Quat)", m_quatOrientation, [pInst](float fW, float fX, float fY, float fZ) { pInst->m_stackMemUndoType.push(ENT_MEM_ROTATE); pInst->m_stackMemUndoQuat.push(pInst->getOrientation()); pInst->saveState(); pInst->m_quatOrientation.Get()[0] = fW; pInst->m_quatOrientation.Get()[1] = fX; pInst->m_quatOrientation.Get()[2] = fY; pInst->m_quatOrientation.Get()[3] = fZ; pInst->setOrientation(pInst->m_quatOrientation); }, false); IWE_PROP_LEVEL_END(); IWE_IMPLEMENT_PROP_END() We are finding an simplified way to this, without leading confusing the programmers, (will be released to the public) i find ways to achieve this but they are only available for the common scripting as Lua or editors using C#. also too portable, we can write "wrappers" for different GUI toolkits as Qt or GTK, also i'm thinking to using Boost.Wave to get additional macro functionality without creating my own compiler. The properties designed to use in the editor they are removed in the game since the save file contains their data and loads it using an simple 'load' function to reduce unnecessary code bloat may will be useful if some GameObject property wants to be hidden instead. In summary, there's a way to implement an reflection(property) system for a level editor based in properties from derived classes? Also we can use C++11 and Boost (restricted only to Wave and PropertyTree)

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  • Gizmodo Made No Money On Their iPhone 4G Scoop Blog Posts

    - by Gopinath
    Amit Agarwal of Labnol reported couple of days ago that Gizmodo would have made $150,000 from the iPhone 4G scoop that revealed  all the secrets about iPhone 4G. But the reality seems to be entirely different. Gawker Media owner Nick Denton says that "There were no immediate revenue benefits whatsoever — in fact, only costs,"(via businessinsider) Gizmodo paid $5,000 to get hold of iPhone 4G which was lost by an Apple Engineer at a bar after his birthday party. Plus an additional amount of $7000 is spent on keeping the servers up to server 23 page views attracted by the iPhone 4G blog posts. Irrespective of whether Gizmodo made profits or not, they got huge publicity. But at the same time Apple should be very angry with Gizmodo for derailing it’s planned unveiling of the product. We have to wait and see what action Apple is going to take against Gizmodo. Join us on Facebook to read all our stories right inside your Facebook news feed.

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  • James Atkinson - New Blog Home

    - by jatkinson
    I'm migrating my blog that is currently hosted over at vbCity.com (which is an outstanding developer community!) to a new home at geekswithblogs.net. I truly appreciate the comradery of Serge B, Ged Mead, and the other team members at the "City". What you can expect to find here (my interests): Most .NET programming topics General computing Language examples in C#, VB.NET, and Boo WCF WPF Mathematical / GPS solutions F# (in progress... if you can say that much) Obsessed with code performance (speed) Some photography My background: Kansas State University Grad (Agriculture Technology Management) From Richmond, VA Self taught programmer (started with C# in VS2002) NOT a professional programmer (enables free thinking?!)  I'm no Jeff Atwood or Beth Massi, but you should expect to see some interesting stuff to follow.

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  • John Burke's Weclome to the Applications Strategy Blog

    - by Tony Ouk
    Hi I'm John Burke and I'm the group Vice President of Oracle's Applications Business Unit.  Thanks for stopping by our Applications blog today.  The purpose of this site is to provide you, our customers, with timely, relevant, and balanced information about the state of the applications business, both here at Oracle and industry-wide. So on this site, you'll find information about Oracle's application products, how our customers have used those products to transform their businesses, and general industry trends which might help you craft YOUR applications roadmap.  So right now I'm walking to meet with one of Oracle's development executives.  I also plan to talk to Oracle customers and leading industry analysts.  I plan to provide a complete and balanced view of the total applications landscape.  I hope you check back often and view our updates.

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  • Simple Java networking game engine [on hold]

    - by Florian Peschka
    I want to create a simple java networking game and search a networking engine that eases use of sockets etc. I have already read some questions on here and the internet about java networking for games, but many of them were over 10 years old or not really answered. I have no idea whatsoever about what exactly I need to send in terms of messages, but I figured simple strings or integers will be enough for my purposes. It's basically a peer to peer game, so I don't need a centralized server structure. Messaging doesn't have to have an extremely low ping, yet of course all players need to have a synchronized view. What are the possibilities I have here?

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  • ASP.NET 4.0 meta tags and Search engine optimisation

    - by nikolaosk
    I am thinking to create a new series of posts regarding ASP.NET and SEO (Search Engine Optimisation). I am going to start with this post , talking about some new features that make our asp.net apps more SEO friendly. At the end of the day, there is no point having a great application and somehow "scare" the search engines away. This is going to be a short post so let's quickly have a look at meta keywords and ASP.NET 4.0. Meta keywords and description are important elements of a page and make it...(read more)

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  • The Expert Secret to Search Engine Optimization - Effective Website Optimization

    Throwing keywords into a program that shows you how popular they are and then using those keywords without doing a little bit of preliminary research and answering some very important questions can just spell disaster. There are three questions that are extremely important to ask yourself before just doing random search engine optimization. And believe it or not those three questions are not, "What are the most popular keywords for my particular website?" Those questions are much more fundamental and strategic and they can be much more important to your overall efforts in getting your site ranked on the search engines.

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  • New Survey 1.2.0 release - The open source web survey and form engine

    New Survey 1.2.0 release published today at http://survey.codeplex.com including multilanguage features and many new additions. Survey is a free web based survey and form engine toolkit for Microsoft's .net. written in asp.net and C#. The Survey project is a restart of the open source websurvey solution NSurvey. A demosite is available at http://survey.dotnetnukes.com New Survey 1.2.0 release published today at http://survey.codeplex.com including multilanguage features and many new additions.Survey...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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  • New Survey 1.2.0 release - The open source web survey and form engine

    New Survey 1.2.0 release published today at http://survey.codeplex.com including multilanguage features and many new additions. Survey is a free web based survey and form engine toolkit for Microsoft's .net. written in asp.net and C#. The Survey project is a restart of the open source websurvey solution NSurvey. A demosite is available at http://survey.dotnetnukes.com New Survey 1.2.0 release published today at http://survey.codeplex.com including multilanguage features and many new additions.Survey...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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  • Yet another blog about IValueConverter

    - by codingbloke
    After my previous blog on a Generic Boolean Value Converter I thought I might as well blog up another IValueConverter implementation that I use. The Generic Boolean Value Converter effectively converters an input which only has two possible values to one of two corresponding objects.  The next logical step would be to create a similar converter that can take an input which has multiple (but finite and discrete) values to one of multiple corresponding objects.  To put it more simply a Generic Enum Value Converter. Now we already have a tool that can help us in this area, the ResourceDictionary.  A simple IValueConverter implementation around it would create a StringToObjectConverter like so:- StringToObjectConverter using System; using System.Windows; using System.Windows.Data; using System.Linq; using System.Windows.Markup; namespace SilverlightApplication1 {     [ContentProperty("Items")]     public class StringToObjectConverter : IValueConverter     {         public ResourceDictionary Items { get; set; }         public string DefaultKey { get; set; }                  public StringToObjectConverter()         {             DefaultKey = "__default__";         }         public virtual object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)         {             if (value != null && Items.Contains(value.ToString()))                 return Items[value.ToString()];             else                 return Items[DefaultKey];         }         public virtual object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)         {             return Items.FirstOrDefault(kvp => value.Equals(kvp.Value)).Key;         }     } } There are some things to note here.  The bulk of managing the relationship between an object instance and the related string key is handled by the Items property being an ResourceDictionary.  Also there is a catch all “__default__” key value which allows for only a subset of the possible input values to mapped to an object with the rest falling through to the default. We can then set one of these up in Xaml:-             <local:StringToObjectConverter x:Key="StatusToBrush">                 <ResourceDictionary>                     <SolidColorBrush Color="Red" x:Key="Overdue" />                     <SolidColorBrush Color="Orange" x:Key="Urgent" />                     <SolidColorBrush Color="Silver" x:Key="__default__" />                 </ResourceDictionary>             </local:StringToObjectConverter> You could well imagine that in the model being bound these key names would actually be members of an enum.  This still works due to the use of ToString in the Convert method.  Hence the only requirement for the incoming object is that it has a ToString implementation which generates a sensible string instead of simply the type name. I can’t imagine right now a scenario where this converter would be used in a TwoWay binding but there is no reason why it can’t.  I prefer to avoid leaving the ConvertBack throwing an exception if that can be be avoided.  Hence it just enumerates the KeyValuePair entries to find a value that matches and returns the key its mapped to. Ah but now my sense of balance is assaulted again.  Whilst StringToObjectConverter is quite happy to accept an enum type via the Convert method it returns a string from the ConvertBack method not the original input enum type that arrived in the Convert.  Now I could address this by complicating the ConvertBack method and examining the targetType parameter etc.  However I prefer to a different approach, deriving a new EnumToObjectConverter class instead. EnumToObjectConverter using System; namespace SilverlightApplication1 {     public class EnumToObjectConverter : StringToObjectConverter     {         public override object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)         {             string key = Enum.GetName(value.GetType(), value);             return base.Convert(key, targetType, parameter, culture);         }         public override object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)         {             string key = (string)base.ConvertBack(value, typeof(String), parameter, culture);             return Enum.Parse(targetType, key, false);         }     } }   This is a more belts and braces solution with specific use of Enum.GetName and Enum.Parse.  Whilst its more explicit in that the a developer has to  choose to use it, it is only really necessary when using TwoWay binding, in OneWay binding the base StringToObjectConverter would serve just as well. The observant might note that there is actually no “Generic” aspect to this solution in the end.  The use of a ResourceDictionary eliminates the need for that.

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  • First Blog Entry & OracleWebLogic YouTube Channel

    - by Jeffrey West
    This is my fist blog post ever!  I'll be blogging about WebLogic, Exalogic and other... logics...In the meantime check out our Oracle WebLogic YouTube Channel!  We have 50+ subscribers and growing!  We really want to hear feedback from our WebLogic users so let us know how we are doing.  Leave a comment on our WebLogic channel, comment on one of our videos or comment on our blogs and let us know what you want to see from us!

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  • [Blog] N'utilisez jamais try {} catch {}

    C'est en somme le conseil donn? par Karl Seguin sur son blog. Pour lui, l'utilisation du try/catch pour g?rer une exception est une mauvaise pratique : "If an exception happens, you need to know about it. If a truly unexpected exception happens, you're better off (most of the time) crashing than letting the application continue (...) The best way to achieve both is let the exception go unhandled and log the exception in a global exception handler". Pour paraphraser une ?mission c?l?bre, ?a se discute ...

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