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  • alt-tab sort of web design

    - by sureshgl
    I am thinking of designing a web site having multiple related services. For every action of the user in a service there will be some computation going on in each of the other services. I want to display the service in action (chosen by the user) in the middle of the page in enlarged mode and rest of the services as small sized (shrunk) versions around the enlarged mode. The services which are shown in the shrunk version, should actually show what is happening in that service, at run time as if that was the chosen service. A close match to this sort of behavior I know is in Reliance BigTV, where all the small images of all the channels will be going on, and we can choose the one that we want to watch. After choosing that one image will become big and occupy the screen. Please, let me know if I can do some thing like this using css, html, ajax & php.

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  • 12.04 on Pentium Dual Core with 1GB or ram running slow

    - by Alex
    hey i have a Lenovo Thinkpad Laptop with Ubuntu 12.04 installed. It runs slow. I tried "System profiler and Benchmark" to test the computer. but the application quits and closes after the first few benchmark test. before it even gets to the other tests. So i tried "Hardinfo" that installed on the Puppy Linux live cd. that did the same thing (the apps look just a like). the memory usage isnt the problem on this pc. its the cpu processes. just running the "system profiler" app that comes with ubuntu uses about 34% on each core, default with nothing running its 5-10% on each core. i cant really find what the deal is other than that ubuntu is a cpu hog. so im testing unity2D at the moment to see how it goes. if you have any other suggestions, feel free to answer this question. thanks

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  • The next step & technology towards web services.

    - by webzide
    Hi, My name is Dennis and I am pretty ambitious of creating the next big thing for the web. I have ideas but now I gotta get to work to learn the tools. I am learning Javascript. I don't know if next step for me to take is PHP or some suggests RUBY on Rails. What are the pros and cons. With your experience, I wish you could hint me to the right direction. Thanks. I don't mind working hard. My goal is to create a comprehensive and secure web service platform as well as a fast and user friendly UI.

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  • Web development for people who mainly do client side..

    - by kamziro
    Okay, I'm sure there are a lot of us that has plenty of experience developing c++/opengl/objective C on the iPhone, java development on android, python games, etc (any client side stuff) while having little to no experience on web-based development. So what skillset should one learn in order to be able to work on web projects, say, to make a facebook clone (I kid), or maybe a startup that specializes on connecting random fashionistas with pics etc. I actualy do have some experience with C#/VB.net back-end development a while back, but as part of a team, I had a lot of support from the senior devs. Is C# considered a decent web development language?

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  • Web Services Example - Part 2: Programmatic

    - by Denis T
    In this edition of the ADF Mobile blog we'll tackle part 2 of our Web Service examples.  In this posting we'll take a look at using a SOAP Web Service but calling it programmatically in code and parsing the return into a bean. Getting the sample code: Just click here to download a zip of the entire project.  You can unzip it and load it into JDeveloper and deploy it either to iOS or Android.  Please follow the previous blog posts if you need help getting JDeveloper or ADF Mobile installed.  Note: This is a different workspace than WS-Part1 Defining our Web Service: Just like our first installment, we are using the same public weather forecast web service provided free by CDYNE Corporation.  Sometimes this service goes down so please ensure you know it's up before reporting this example isn't working. We're going to concentrate on the same two web service methods, GetCityForecastByZIP and GetWeatherInformation. Defing the Application: The application setup is identical to the Weather1 version.  There are some improvements to the data that is displayed as part of this example though.  Now we are able to show the associated image along with each forecast line when using the Forecast By Zip feature.  We've also added the temperature Hi/Low values into the UI. Summary of Fundamental Changes In This Application The most fundamental change is that we're binding the UI to the Bean Data Controls instead of directly to the Web Service Data Controls.  This gives us much more flexibility to control the shape of the data and allows us to do caching of the data outside of the Web Service.  This way if your application is, say offline, your bean could still populate with data from a local cache and still show you some UI as opposed to completely failing because you don't have any connectivity. In general we promote this type of programming technique with ADF Mobile to insulate your application from any issues with network connectivity. What's different with this example? We have setup the Web Service DC the same way but now we have managed beans to process the data.  The following classes define the "Model" of our application:  CityInformation-CityForecast-Forecast, WeatherInformation-WeatherDescription.  We use WeatherBean for UI interaction to the model layer.  If you look through this example, we don't really do that much with the java code except use it to grab the image URL from the weather description.  In a more realistic example, you might be using some JDBC classes to persist the data to a local database. To have a good architecture it is always good to keep your model and UI layers separate.  This gets muddied if you start to use bindings on a page invoked from Java code and this java code starts to become your "model" layer.  Since bindings are page specific, your model layer starts to become entwined with your UI.  Not good!  To help with this, we've added some utility functions that let you invoke DC methods without having a binding and thus execute methods from your "model" layer without requiring a binding in your page definition.  We do this with the invokeDataControlMethod of the AdfmfJavaUtilities class.  An example of this method call is available in line 95 of WeatherInformation.java and line 93 of CityInformation.Java. What's a GenericType? Because Web Service Data Controls (and also URL Data Controls AKA REST) use generic name/value pairs to define their structure and don't have strongly typed objects, these are actually stored internally as GenericType objects.  The GenericType class is simply a property map of name/value pairs that can be hierarchical.  There are methods like getAttribute where you supply the index of the attribute or it's string property name.  Why is this important to know?  Because invokeDataControlMethod returns GenericType objects and developers either need to parse these GenericType objects themselves or use one of our helper functions. GenericTypeBeanSerializationHelper This class does exactly what it's name implies.  It's a helper class for developers to aid in serialization of GenericTypes to/from java objects.  This is extremely handy if you have a large GenericType object with many attributes (or you're just lazy like me!) and you just want to parse it out into a real java object you can use more easily.  Here you would use the fromGenericType method.  This method takes the class of the Java object you wish to return and the GenericType as parameters.  The method then parses through each attribute in the GenericType and uses reflection to set that same attribute in the Java class.  Then the method returns that new object of the class you specified.  This is obviously very handy to avoid a lot of shuffling code between GenericType and your own Java classes.  The reverse method, toGenericType is also available when you want to go the other way.  In this case you supply the string that represents the package location in the DataControl definition (Example: "MyDC.myParams.MyCollection") and then pass in the Java object you have that holds the data and a GenericType is returned to you.  Again, it will use reflection to calculate the attributes that match between the java class and the GenericType and call the getters/setters on those. Issues and Possible Improvements: In the next installment we'll show you how to make your web service calls asynchronously so your UI will fill dynamically when the service call returns but in the meantime you show the data you have locally in your bean fed from some local cache.  This gives your users instant delivery of some data while you fetch other data in the background.

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  • Are these jobs for developer or designers or for client itself? for a web-site projects

    - by jitendra
    Spell checking grammar checking Descriptive alt text for big chart , graph images, technical images To write Table summary and caption Descriptive Link text Color Contrast checking Deciding in content what should be H2 ,H3, H4... and what should be <strong> or <span class="boldtext"> Meta Description and keywords for each pages Image compression To decide Filenames for images,PDf etc To decide Page's <title> for each page

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  • What does a node.js web application's setup look like on a real production server?

    - by joe
    Being new to node js magic world, i'm wondering how does a web application's setup look like on a real production server? So far all tutorials, create the js file that is started from a console...and that's it. Anyone has created a real world web app that uses node js in the back end? Can you please describe how is it setup, and how reliable this infrastructure is ? I'm coming from the asp.net and php world that require heavy web servers...and can't have a clear idea about node stuff.

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  • Implementing Multitasking on an iPhone/iOS4 Web App

    - by Peter Watts
    I am looking to build a web app that implements background audio and fast app switching. These features work out of the box, when run as regular Safari web pages, but as soon as you add the web-app-capable tag, and try to run in full screen mode, this functionality breaks. I did some testing and even the most basic web app will reload every time when you switch back to it. And seeing as it's a web app, we can't exactly implement the multitasking API. Has anyone found a work around? This isn't a deal-breaker, as you can just avoid full screen mode, but then you also lose the ability to use your own icon in the app switch tray. Perhaps this explains a lack of full screen mode in YouTube's new web app....

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  • How to manage unprivileged administration of system services using Debian?

    - by ypnos
    At our lab, we have several services handled by different phd students (like myself). Fluctuation is high and people do the job next to their research duties. Until now, services were running on different machines, with different OS setups that can result in administration hell quickly. We want to consolidate our service setup. Our main idea is that the guys responsible for the services should not meddle with the underlying system anymore. Apart from core systems like NFS and kerberos, a typical service is able to run as non-root already. I'm talking about apache, mysql, subversion, mail with openxchange, and so on. Redirecting privileged ports is also no issue (source). What is left is the configuration of the service and its payload. One scenario we envisioned is that every service has its own user and home directory, accessable by the corresponding admins. Backup and fallback of the service is easy, as everything needed for the service to run is found in one place. Are there established ways to create such a setup? Does a mostly unique method exist to make services find their files (other than in system directories) while still using the corresponding debian packages? Are there any catches with our idea that we may have overlooked? Would you maybe claim that virtualization is the answer to our problem? (In our POV, it wouldn't help us keeping system setup strictly separated from service setup.) Thank you for any advice!

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  • Running Server With minimum core OS with VM

    - by user170019
    I want to start a server but all my application will be in a virtual partition. Therefore, I need just a very minimal core OS that can support virtualbox as there will no usage of core OS other than start up the virtualbox. Any OS that is suitable for this situation? Tried JEOS and Fedora minimal installation which is only CLI. However, I cant make those 2 OS to support virtualbox. Please help. Sorry Im totally new to Unix and CLI. Thanks

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  • How do I temporarily reference a new web host using my existing domain name?

    - by Alex Angas
    On provider A I have an existing web hosting account running my site. On provider B I have my domain name registered pointing to the web hosting on provider A. I've just purchased a web hosting account with provider B and want to move my site there. Is there a way to temporarily use my domain name to point to provider B while I set up the site (e.g. just from my computer)? I tried to change the HOSTS file (Windows) and while pings resolved to what I set, HTTP requests don't.

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  • Web hosting announced downtime and how it affects FORWARD domain names?

    - by maple_shaft
    Our web hosting provider that holds our FORWARD domain names announced that at some point in the next couple weeks they will be migrating servers and that this will cause a 5-10 minute downtime at some point in that week during what happens to be our core business hours. They cite for technical reasons it is impossible to give an exact date or time when this downtime will occur. My questions are: If my domains are set to FORWARD to a static IP on servers not hosted by the web hosting provider in question then will this affect the DNS servers correctly routing to my website? Are their legitimate technical reasons for such a wide window of time, or could this just be a blanket statement to cover laziness in not being more organized with their server migrations? Are such downtimes normal for web hosting providers, or should I start to consider other providers?

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  • core.* files eating up server space (~50MB)

    - by skytreader
    I'm renting server space from someone and, upon logging in my control panel after quite sometime, noticed an abnormal spike (~50MB) in the disk usage. Upon investigating, I found a lot of core.* files scattered around my public_html directory. Each one is more than 5MB in size but no more than 6MB. The * part is all numbers (in programming regex, that should be core\.\d+). I downloaded one and checked the contents. There was a lot of balderdash characters (NUL mostly, but also a scattering of ETB, ETX, STX) but there's this block of readable text which says: This text is part of the internal format of your mail folder, and is not a real message. It is created automatically by the mail system software. If deleted, important folder data will be lost, and it will be re-created with the data reset to initial values. Pretty self-explanatory. A few blocks above the text are some more readable messages that look like logs but is sandwiched in between non printable characters. I've extracted some below. Scan not valid for mh mailboxes Bogus character 0x%x in news state Can't rewrite news state %.80s Error closing backup news state %.80s No state for newsgroup %.80s found Now, a few concerns: Am I under attack? The messages seem to be about my webmail but I don't use my personal webmail that much---only for a vanity email address and an inbox for an outdated comments system. However, lately, I seem to notice a spike in the spam for my vanity mail. (Note: the comments system is covered by a captcha but every now and then some get through. My vanity email has a spam filter but it isn't as good as I'd like). Next, if this is a feature, can I turn it off? Is it advisable to? I've only 150MB so you see why I'm fretting over a 50MB spike. Some final details: my only server-side scripts are in PHP. The directory which accumulated the most number of these core files is the one containing the Wordpress-managed subdomain of my site. I manage my server through CPanel. Lastly, I decided to delete this files and after some checking nothing seems amiss in my websites nor in my mail. They are indeed the ones responsible for the ~50MB spike as my disk space usage is back to expected.

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  • Where should i save my images that user uploads? java web application

    - by Nitesh Panchal
    Hello, I am saving the image at this location :- private static String photoGalleryPath = "/Common/PhotoGallery/"; In PhotoGallery. I create userid wise folders and save images. Everything works fine. But when i clean and build my project. The whole folder of PhotoGallery gets deleted. This looks very funny to me :). Why does it delete my whole folder everytime? And what more should i do to tell the extra smart Glassfish to not to delete my folders?

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  • gwt seperate modules with no code sharing

    - by Code freak
    Hi, I have to make a web application using GWT. The project has a core module that'll expose a set of apis to be used by other apps; each of these app are unrelated. Each shall be loaded in a separate iframe. My idea was to compile core into core.js and each app shall have its own app1.js app2.js and so on... App1 script type="text/javascript" src="core.js" ></script> script type="text/javascript" src="app1.js" ></script> with this design, due to browser caching, each app laod only the app.js which should be smaller ~20kb in size. Making a core module is straightforward but the apps are problematic. The reason being after compilation, each app contains the entire GWT library - this substantially increases the download size of the complete webapp. Can anyone suggest a way to get aroung this problem ? I've checked similar questions on SO, but failed to find a simple working answer fr the problem. Thanks for any help.

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  • Will .NET 4.0 apps work on Win 2008 R2 Server Core?

    - by markus
    When Windows Server 2008 R2 was launched, the "server core" edition started to become useful to me, because it lets me deploy .NET background applications isolated on their own virtual machine instance with only a small fraction of all the disk space overhead of a default Windows Server installation, and very few Windows Updates. It comes with a subset of .NET 3.5 SP1 integrated (as an optional feature). Now that .NET 4.0 is released, the redistributables explicitly state that it's not support on Server Core. Any chance that there will be a separate download available for Server Core (e. g. without WPF) any time soon, has anybody heard about it?

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  • Running my web site in a 32-bit application pool on a 64-bit OS.

    - by Jeremy H
    Here is my setup: Dev: - Windows Server 2008 64-bit - Visual Studio 2008 - Solution with 3 class libraries, 1 web application Staging Web Server: - Windows Server 2008 R2 64-bit - IIS7.5 Integrated Application Pool with 32-bit Applications Enabled In Visual Studio I have set all 4 of my projects to compile to 'Any CPU' but when I run this web application on the web server with the 32-bit application pool it times out and crashes. When I run the application pool in 64-bit mode it works fine. The production web server requires me to run 32-bit application pool in 64-bit OS which is why I have this configured in this way on the staging web server. (I considered posting on ServerFault but the server part seems to be working fine. It is my code specifically that doesn't seem to want to run in 32-bit application pool which is why I am posting here.)

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  • Compact web server with Lua support?

    - by OverTheRainbow
    Hello, I need to find a very compact, cross-platform web server that can run Lua scripts, ie. either a regular web server like Mongoose that will forward queries to a Lua program in eg. FastCGI, or a web server itself written in Lua which will save the need to provide a separate web server. I recently started learning about Lua so am still in the dark about what is available out there, save for the three I came accross: Barracuda Embedded Web Server http://barracudaserver.com/ba/doc/ Xavante - Lua HTTP 1.1 Web server http://keplerproject.github.com/xavante/ Haserl http://haserl.sourceforge.net/ If someone's already done this recently, what solution would you recommend along with any tutorial/article that would get me started? Thank you.

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  • Installed 12.04 from CD problems with compiz-core - wont continue - just

    - by user70886
    Installed 12.04 from CD to clean hard drive but on first boot up says problems with compiz-core. Clicked continue with it not installed. After I sent info for help; it came back with some packages are not up to date. Said I need to update compiz-core and libylib2.0-0 Cancelled the process to send info (after second time) but it wont cancel and it wont load the desktop. What do I do now? Right click will let me create a new folder/document or organise desktop by name etc but I cannot see the usual system bar or left menu items. Is there a way to load the terminal and reload the desktop. If this was windows I'd use cntrl alt delete and run explorer to fix the desktop.

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  • What's the reason why core data takes care of the life-cycle of modeled properties?

    - by mystify
    The docs say that I should not release any modeled property in -dealloc. For me, that feels like violating the big memory management rules. I see a big retain in the header and no -release, because Core Data seems to do it at any other time. Is it because Core Data may drop the value of a property dynamically, at any time when needed? And what's Core Data doing when dropping an managed object? If there's no -dealloc, then how and when are the properties getting freed up?

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  • Unity and web service

    - by zachary
    I had this awesome idea... but I am afraid maybe it is actually a bad idea.... we use unity for dependency injection. I make interfaces from my web services using partial classes for the purpose of mocking and web services.... What I want to do is put my web services into unity and get them via dependency injection... What do you think? Is there too much overhead somewhere? Memory leaks? Is this a bad idea?

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  • Web UI element to represent two different micro-views of data in the same spot?

    - by Chris McCall
    I've been tasked with laying out a portion of a screen for a customer care (call center) app that serves as sort of a header/summary block at the top of the screen. Here's what it looks like: The important part is in the red box. That little tooltip is the biz's vision for how to represent both the numeric SiteId and the textual Site Name all in the same piece of screen real estate. I asked, and the business thinks the Name is more important than the ID, but lists the Id by default, because the Name can't be truncated in the display, and there's only so much horizontal room to put the data. So they go with the Id, because it's fewer characters, and then they have the user mouse-over the Id to display the name (presumably because the tooltip can be of unlimited width and since it's floating over the rest of the screen, the full name will always be displayed. So, here's my question: Is there some better UI metaphor that I don't know about that could get this job done, while meeting the following constraints?: Does not require the mouse (uses a keyboard shortcut to do the "reveal") Allows the user to copy and paste the name Will not truncate the name Provides for the display of both the ID and name in the same spot Works with IE7

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  • Will this web service accept both raw xml and an object?

    - by ChadNC
    We have a web service that provides auto insurance quotes and a company that provides an insurance agency management system would like to use the web service for thier client but they want to pass the web service raw xml instead of using the wsdl to create a port, the object the service expects and calling the web method. The web service has performed flawlessly by creating an object like so com.insurance.quotesvc.AgencyQuote service = new com.insurance.quotesvc.AgencyQuote(); com.insurance.quotesvc.QuotePortType port = service.getQuotePortType(); com.insurance.quotesvc.schemas.request.ACORD parameter = null; Then create initialize the request object with the other objects that make up the response. parameter = factory.createACORD(); parameter.setSignonRq(signOn); parameter.setInsurancesSvcRq(svcRq); And send the request to the web service. com.insurance.quotesvc.schemas.response.ACORD result = null; result = port.requestQuote(parameter); By doing that I am able to easily marshall the request and the result into an xml file and do with them as I wish. So if a client was to send the web service via an http post as raw xml inside of a soap envelope. Would the web service be able to handle the xml without any changes being made to the web service or would there need to be changes made to the web service in order for it to handle a request of that type? The web service is a JAX_WS and we currently have both Java and C# clients consuming the web service using the method described above but now there is another client who wants to send raw xml inside of a soap envelope instead of creating the objects. I feel pretty sure that they will be making the call to the web service using vb. I'm sure I'm missing something obvious but it is eluding me at the moment and any help is greatly appreciated.

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  • Using the West Wind Web Toolkit to set up AJAX and REST Services

    - by Rick Strahl
    I frequently get questions about which option to use for creating AJAX and REST backends for ASP.NET applications. There are many solutions out there to do this actually, but when I have a choice - not surprisingly - I fall back to my own tools in the West Wind West Wind Web Toolkit. I've talked a bunch about the 'in-the-box' solutions in the past so for a change in this post I'll talk about the tools that I use in my own and customer applications to handle AJAX and REST based access to service resources using the West Wind West Wind Web Toolkit. Let me preface this by saying that I like things to be easy. Yes flexible is very important as well but not at the expense of over-complexity. The goal I've had with my tools is make it drop dead easy, with good performance while providing the core features that I'm after, which are: Easy AJAX/JSON Callbacks Ability to return any kind of non JSON content (string, stream, byte[], images) Ability to work with both XML and JSON interchangeably for input/output Access endpoints via POST data, RPC JSON calls, GET QueryString values or Routing interface Easy to use generic JavaScript client to make RPC calls (same syntax, just what you need) Ability to create clean URLS with Routing Ability to use standard ASP.NET HTTP Stack for HTTP semantics It's all about options! In this post I'll demonstrate most of these features (except XML) in a few simple and short samples which you can download. So let's take a look and see how you can build an AJAX callback solution with the West Wind Web Toolkit. Installing the Toolkit Assemblies The easiest and leanest way of using the Toolkit in your Web project is to grab it via NuGet: West Wind Web and AJAX Utilities (Westwind.Web) and drop it into the project by right clicking in your Project and choosing Manage NuGet Packages from anywhere in the Project.   When done you end up with your project looking like this: What just happened? Nuget added two assemblies - Westwind.Web and Westwind.Utilities and the client ww.jquery.js library. It also added a couple of references into web.config: The default namespaces so they can be accessed in pages/views and a ScriptCompressionModule that the toolkit optionally uses to compress script resources served from within the assembly (namely ww.jquery.js and optionally jquery.js). Creating a new Service The West Wind Web Toolkit supports several ways of creating and accessing AJAX services, but for this post I'll stick to the lower level approach that works from any plain HTML page or of course MVC, WebForms, WebPages. There's also a WebForms specific control that makes this even easier but I'll leave that for another post. So, to create a new standalone AJAX/REST service we can create a new HttpHandler in the new project either as a pure class based handler or as a generic .ASHX handler. Both work equally well, but generic handlers don't require any web.config configuration so I'll use that here. In the root of the project add a Generic Handler. I'm going to call this one StockService.ashx. Once the handler has been created, edit the code and remove all of the handler body code. Then change the base class to CallbackHandler and add methods that have a [CallbackMethod] attribute. Here's the modified base handler implementation now looks like with an added HelloWorld method: using System; using Westwind.Web; namespace WestWindWebAjax { /// <summary> /// Handler implements CallbackHandler to provide REST/AJAX services /// </summary> public class SampleService : CallbackHandler { [CallbackMethod] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } } } Notice that the class inherits from CallbackHandler and that the HelloWorld service method is marked up with [CallbackMethod]. We're done here. Services Urlbased Syntax Once you compile, the 'service' is live can respond to requests. All CallbackHandlers support input in GET and POST formats, and can return results as JSON or XML. To check our fancy HelloWorld method we can now access the service like this: http://localhost/WestWindWebAjax/StockService.ashx?Method=HelloWorld&name=Rick which produces a default JSON response - in this case a string (wrapped in quotes as it's JSON): (note by default JSON will be downloaded by most browsers not displayed - various options are available to view JSON right in the browser) If I want to return the same data as XML I can tack on a &format=xml at the end of the querystring which produces: <string>Hello Rick. Time is: 11/1/2011 12:11:13 PM</string> Cleaner URLs with Routing Syntax If you want cleaner URLs for each operation you can also configure custom routes on a per URL basis similar to the way that WCF REST does. To do this you need to add a new RouteHandler to your application's startup code in global.asax.cs one for each CallbackHandler based service you create: protected void Application_Start(object sender, EventArgs e) { CallbackHandlerRouteHandler.RegisterRoutes<StockService>(RouteTable.Routes); } With this code in place you can now add RouteUrl properties to any of your service methods. For the HelloWorld method that doesn't make a ton of sense but here is what a routed clean URL might look like in definition: [CallbackMethod(RouteUrl="stocks/HelloWorld/{name}")] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } The same URL I previously used now becomes a bit shorter and more readable with: http://localhost/WestWindWebAjax/HelloWorld/Rick It's an easy way to create cleaner URLs and still get the same functionality. Calling the Service with $.getJSON() Since the result produced is JSON you can now easily consume this data using jQuery's getJSON method. First we need a couple of scripts - jquery.js and ww.jquery.js in the page: <!DOCTYPE html> <html> <head> <link href="Css/Westwind.css" rel="stylesheet" type="text/css" /> <script src="scripts/jquery.min.js" type="text/javascript"></script> <script src="scripts/ww.jquery.min.js" type="text/javascript"></script> </head> <body> Next let's add a small HelloWorld example form (what else) that has a single textbox to type a name, a button and a div tag to receive the result: <fieldset> <legend>Hello World</legend> Please enter a name: <input type="text" name="txtHello" id="txtHello" value="" /> <input type="button" id="btnSayHello" value="Say Hello (POST)" /> <input type="button" id="btnSayHelloGet" value="Say Hello (GET)" /> <div id="divHelloMessage" class="errordisplay" style="display:none;width: 450px;" > </div> </fieldset> Then to call the HelloWorld method a little jQuery is used to hook the document startup and the button click followed by the $.getJSON call to retrieve the data from the server. <script type="text/javascript"> $(document).ready(function () { $("#btnSayHelloGet").click(function () { $.getJSON("SampleService.ashx", { Method: "HelloWorld", name: $("#txtHello").val() }, function (result) { $("#divHelloMessage") .text(result) .fadeIn(1000); }); });</script> .getJSON() expects a full URL to the endpoint of our service, which is the ASHX file. We can either provide a full URL (SampleService.ashx?Method=HelloWorld&name=Rick) or we can just provide the base URL and an object that encodes the query string parameters for us using an object map that has a property that matches each parameter for the server method. We can also use the clean URL routing syntax, but using the object parameter encoding actually is safer as the parameters will get properly encoded by jQuery. The result returned is whatever the result on the server method is - in this case a string. The string is applied to the divHelloMessage element and we're done. Obviously this is a trivial example, but it demonstrates the basics of getting a JSON response back to the browser. AJAX Post Syntax - using ajaxCallMethod() The previous example allows you basic control over the data that you send to the server via querystring parameters. This works OK for simple values like short strings, numbers and boolean values, but doesn't really work if you need to pass something more complex like an object or an array back up to the server. To handle traditional RPC type messaging where the idea is to map server side functions and results to a client side invokation, POST operations can be used. The easiest way to use this functionality is to use ww.jquery.js and the ajaxCallMethod() function. ww.jquery wraps jQuery's AJAX functions and knows implicitly how to call a CallbackServer method with parameters and parse the result. Let's look at another simple example that posts a simple value but returns something more interesting. Let's start with the service method: [CallbackMethod(RouteUrl="stocks/{symbol}")] public StockQuote GetStockQuote(string symbol) { Response.Cache.SetExpires(DateTime.UtcNow.Add(new TimeSpan(0, 2, 0))); StockServer server = new StockServer(); var quote = server.GetStockQuote(symbol); if (quote == null) throw new ApplicationException("Invalid Symbol passed."); return quote; } This sample utilizes a small StockServer helper class (included in the sample) that downloads a stock quote from Yahoo's financial site via plain HTTP GET requests and formats it into a StockQuote object. Lets create a small HTML block that lets us query for the quote and display it: <fieldset> <legend>Single Stock Quote</legend> Please enter a stock symbol: <input type="text" name="txtSymbol" id="txtSymbol" value="msft" /> <input type="button" id="btnStockQuote" value="Get Quote" /> <div id="divStockDisplay" class="errordisplay" style="display:none; width: 450px;"> <div class="label-left">Company:</div> <div id="stockCompany"></div> <div class="label-left">Last Price:</div> <div id="stockLastPrice"></div> <div class="label-left">Quote Time:</div> <div id="stockQuoteTime"></div> </div> </fieldset> The final result looks something like this:   Let's hook up the button handler to fire the request and fill in the data as shown: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").show().fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, HH:mm EST")); }, onPageError); }); So we point at SampleService.ashx and the GetStockQuote method, passing a single parameter of the input symbol value. Then there are two handlers for success and failure callbacks.  The success handler is the interesting part - it receives the stock quote as a result and assigns its values to various 'holes' in the stock display elements. The data that comes back over the wire is JSON and it looks like this: { "Symbol":"MSFT", "Company":"Microsoft Corpora", "OpenPrice":26.11, "LastPrice":26.01, "NetChange":0.02, "LastQuoteTime":"2011-11-03T02:00:00Z", "LastQuoteTimeString":"Nov. 11, 2011 4:20pm" } which is an object representation of the data. JavaScript can evaluate this JSON string back into an object easily and that's the reslut that gets passed to the success function. The quote data is then applied to existing page content by manually selecting items and applying them. There are other ways to do this more elegantly like using templates, but here we're only interested in seeing how the data is returned. The data in the object is typed - LastPrice is a number and QuoteTime is a date. Note about the date value: JavaScript doesn't have a date literal although the JSON embedded ISO string format used above  ("2011-11-03T02:00:00Z") is becoming fairly standard for JSON serializers. However, JSON parsers don't deserialize dates by default and return them by string. This is why the StockQuote actually returns a string value of LastQuoteTimeString for the same date. ajaxMethodCallback always converts dates properly into 'real' dates and the example above uses the real date value along with a .formatDate() data extension (also in ww.jquery.js) to display the raw date properly. Errors and Exceptions So what happens if your code fails? For example if I pass an invalid stock symbol to the GetStockQuote() method you notice that the code does this: if (quote == null) throw new ApplicationException("Invalid Symbol passed."); CallbackHandler automatically pushes the exception message back to the client so it's easy to pick up the error message. Regardless of what kind of error occurs: Server side, client side, protocol errors - any error will fire the failure handler with an error object parameter. The error is returned to the client via a JSON response in the error callback. In the previous examples I called onPageError which is a generic routine in ww.jquery that displays a status message on the bottom of the screen. But of course you can also take over the error handling yourself: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); }, function (error, xhr) { $("#divErrorDisplay").text(error.message).fadeIn(1000); }); }); The error object has a isCallbackError, message and  stackTrace properties, the latter of which is only populated when running in Debug mode, and this object is returned for all errors: Client side, transport and server side errors. Regardless of which type of error you get the same object passed (as well as the XHR instance optionally) which makes for a consistent error retrieval mechanism. Specifying HttpVerbs You can also specify HTTP Verbs that are allowed using the AllowedHttpVerbs option on the CallbackMethod attribute: [CallbackMethod(AllowedHttpVerbs=HttpVerbs.GET | HttpVerbs.POST)] public string HelloWorld(string name) { … } If you're building REST style API's this might be useful to force certain request semantics onto the client calling. For the above if call with a non-allowed HttpVerb the request returns a 405 error response along with a JSON (or XML) error object result. The default behavior is to allow all verbs access (HttpVerbs.All). Passing in object Parameters Up to now the parameters I passed were very simple. But what if you need to send something more complex like an object or an array? Let's look at another example now that passes an object from the client to the server. Keeping with the Stock theme here lets add a method called BuyOrder that lets us buy some shares for a stock. Consider the following service method that receives an StockBuyOrder object as a parameter: [CallbackMethod] public string BuyStock(StockBuyOrder buyOrder) { var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } public class StockBuyOrder { public string Symbol { get; set; } public int Quantity { get; set; } public DateTime BuyOn { get; set; } public StockBuyOrder() { BuyOn = DateTime.Now; } } This is a contrived do-nothing example that simply echoes back what was passed in, but it demonstrates how you can pass complex data to a callback method. On the client side we now have a very simple form that captures the three values on a form: <fieldset> <legend>Post a Stock Buy Order</legend> Enter a symbol: <input type="text" name="txtBuySymbol" id="txtBuySymbol" value="GLD" />&nbsp;&nbsp; Qty: <input type="text" name="txtBuyQty" id="txtBuyQty" value="10" style="width: 50px" />&nbsp;&nbsp; Buy on: <input type="text" name="txtBuyOn" id="txtBuyOn" value="<%= DateTime.Now.ToString("d") %>" style="width: 70px;" /> <input type="button" id="btnBuyStock" value="Buy Stock" /> <div id="divStockBuyMessage" class="errordisplay" style="display:none"></div> </fieldset> The completed form and demo then looks something like this:   The client side code that picks up the input values and assigns them to object properties and sends the AJAX request looks like this: $("#btnBuyStock").click(function () { // create an object map that matches StockBuyOrder signature var buyOrder = { Symbol: $("#txtBuySymbol").val(), Quantity: $("#txtBuyQty").val() * 1, // number Entered: new Date() } ajaxCallMethod("SampleService.ashx", "BuyStock", [buyOrder], function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError); }); The code creates an object and attaches the properties that match the server side object passed to the BuyStock method. Each property that you want to update needs to be included and the type must match (ie. string, number, date in this case). Any missing properties will not be set but also not cause any errors. Pass POST data instead of Objects In the last example I collected a bunch of values from form variables and stuffed them into object variables in JavaScript code. While that works, often times this isn't really helping - I end up converting my types on the client and then doing another conversion on the server. If lots of input controls are on a page and you just want to pick up the values on the server via plain POST variables - that can be done too - and it makes sense especially if you're creating and filling the client side object only to push data to the server. Let's add another method to the server that once again lets us buy a stock. But this time let's not accept a parameter but rather send POST data to the server. Here's the server method receiving POST data: [CallbackMethod] public string BuyStockPost() { StockBuyOrder buyOrder = new StockBuyOrder(); buyOrder.Symbol = Request.Form["txtBuySymbol"]; ; int qty; int.TryParse(Request.Form["txtBuyQuantity"], out qty); buyOrder.Quantity = qty; DateTime time; DateTime.TryParse(Request.Form["txtBuyBuyOn"], out time); buyOrder.BuyOn = time; // Or easier way yet //FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } Clearly we've made this server method take more code than it did with the object parameter. We've basically moved the parameter assignment logic from the client to the server. As a result the client code to call this method is now a bit shorter since there's no client side shuffling of values from the controls to an object. $("#btnBuyStockPost").click(function () { ajaxCallMethod("SampleService.ashx", "BuyStockPost", [], // Note: No parameters - function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError, // Force all page Form Variables to be posted { postbackMode: "Post" }); }); The client simply calls the BuyStockQuote method and pushes all the form variables from the page up to the server which parses them instead. The feature that makes this work is one of the options you can pass to the ajaxCallMethod() function: { postbackMode: "Post" }); which directs the function to include form variable POST data when making the service call. Other options include PostNoViewState (for WebForms to strip out WebForms crap vars), PostParametersOnly (default), None. If you pass parameters those are always posted to the server except when None is set. The above code can be simplified a bit by using the FormVariableBinder helper, which can unbind form variables directly into an object: FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); which replaces the manual Request.Form[] reading code. It receives the object to unbind into, a string of properties to skip, and an optional prefix which is stripped off form variables to match property names. The component is similar to the MVC model binder but it's independent of MVC. Returning non-JSON Data CallbackHandler also supports returning non-JSON/XML data via special return types. You can return raw non-JSON encoded strings like this: [CallbackMethod(ReturnAsRawString=true,ContentType="text/plain")] public string HelloWorldNoJSON(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } Calling this method results in just a plain string - no JSON encoding with quotes around the result. This can be useful if your server handling code needs to return a string or HTML result that doesn't fit well for a page or other UI component. Any string output can be returned. You can also return binary data. Stream, byte[] and Bitmap/Image results are automatically streamed back to the client. Notice that you should set the ContentType of the request either on the CallbackMethod attribute or using Response.ContentType. This ensures the Web Server knows how to display your binary response. Using a stream response makes it possible to return any of data. Streamed data can be pretty handy to return bitmap data from a method. The following is a method that returns a stock history graph for a particular stock over a provided number of years: [CallbackMethod(ContentType="image/png",RouteUrl="stocks/history/graph/{symbol}/{years}")] public Stream GetStockHistoryGraph(string symbol, int years = 2,int width = 500, int height=350) { if (width == 0) width = 500; if (height == 0) height = 350; StockServer server = new StockServer(); return server.GetStockHistoryGraph(symbol,"Stock History for " + symbol,width,height,years); } I can now hook this up into the JavaScript code when I get a stock quote. At the end of the process I can assign the URL to the service that returns the image into the src property and so force the image to display. Here's the changed code: $("#btnStockQuote").click(function () { var symbol = $("#txtSymbol").val(); ajaxCallMethod("SampleService.ashx", "GetStockQuote", [symbol], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); // display a stock chart $("#imgStockHistory").attr("src", "stocks/history/graph/" + symbol + "/2"); },onPageError); }); The resulting output then looks like this: The charting code uses the new ASP.NET 4.0 Chart components via code to display a bar chart of the 2 year stock data as part of the StockServer class which you can find in the sample download. The ability to return arbitrary data from a service is useful as you can see - in this case the chart is clearly associated with the service and it's nice that the graph generation can happen off a handler rather than through a page. Images are common resources, but output can also be PDF reports, zip files for downloads etc. which is becoming increasingly more common to be returned from REST endpoints and other applications. Why reinvent? Obviously the examples I've shown here are pretty basic in terms of functionality. But I hope they demonstrate the core features of AJAX callbacks that you need to work through in most applications which is simple: return data, send back data and potentially retrieve data in various formats. While there are other solutions when it comes down to making AJAX callbacks and servicing REST like requests, I like the flexibility my home grown solution provides. Simply put it's still the easiest solution that I've found that addresses my common use cases: AJAX JSON RPC style callbacks Url based access XML and JSON Output from single method endpoint XML and JSON POST support, querystring input, routing parameter mapping UrlEncoded POST data support on callbacks Ability to return stream/raw string data Essentially ability to return ANYTHING from Service and pass anything All these features are available in various solutions but not together in one place. I've been using this code base for over 4 years now in a number of projects both for myself and commercial work and it's served me extremely well. Besides the AJAX functionality CallbackHandler provides, it's also an easy way to create any kind of output endpoint I need to create. Need to create a few simple routines that spit back some data, but don't want to create a Page or View or full blown handler for it? Create a CallbackHandler and add a method or multiple methods and you have your generic endpoints.  It's a quick and easy way to add small code pieces that are pretty efficient as they're running through a pretty small handler implementation. I can have this up and running in a couple of minutes literally without any setup and returning just about any kind of data. Resources Download the Sample NuGet: Westwind Web and AJAX Utilities (Westwind.Web) ajaxCallMethod() Documentation Using the AjaxMethodCallback WebForms Control West Wind Web Toolkit Home Page West Wind Web Toolkit Source Code © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery  AJAX   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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