Category Archives: AJAX - Page 3

Ajax Data Transfer Methods – XMLHttpRequest Alternatives

Posted by on October 11, 2007 No comments

XMLHttpRequest is not the only way to implement Ajax – in fact it is not even the most popular one. Take a quick look at the various transport methods in Ajax…

XMLHttpRequest

This is the W3C standard – most modern browsers supports this – browsers like…

* Firefox
* Opera
* Konquror
* Internet Explorer 7
* etc.

ActiveX(XMLHTTP)

This is the preferred method in Internet Explorer. Currently this is the most used method for ajax calls – due to the simple fact that IE has the majority market share. This is basically a different name for XMLHttpRequest – except for the initilization, all the API calls are the same as in XMLHttpRequest(thank God for that).

IE did not have a native XMLHttpRequest object(dispite the fact that they invented the concept). XMLHttpRequest was first introduced to the world as an ActiveX control in Internet Explorer 5.0. Fortunatly, they have native support for XMLHttpRequest from IE 7 onwards.

IFrame

This is used as a fallback for older browsers by some ajax libraries. In this method you load the URL in a (typically) hidden iframe element. Once the iframe has compleated loading, you can read the contents of the iframe. That way, you have a working Ajax system even in very old browsers.

One of the main advantages of this method is that it does not have the cross-domain issue(also known as the same origin restriction).

Image Source

This is not a popular transfer method – in fact, I have seen it in use only once. The basic concept is that you can point an image’s src to a server-side script. That script can do the necessary operation on the server and then return the image.

The major disadvantage of this method is that data can only be passed to the server – the server cannot pass data back to the client. Well, it is possible – if you set a cookie on the server and then read it in the client side. Trust me, you don’t need that kind of headaches – Ajax development is enough trouble as it is.

But it has a few advantages too…

* No cross domain issue
* Works with old browsers

Script Tag

This uses the same principle as the Image method – the only difference is that you use a script instead of an Image tag. That way, the server can return data to the client side as well.

This is a very popular method in the mashup scene. The main reason is this method don’t have the cross domain issue. For example del.icio.us offers this as a choice to get data from their site.

This method is also possible using a stylesheet – but I don’t want to go into that.

Non Javascript methods
Flash

Flash can be used to get data from the server and pass it to the javascript code.

Java Applets

I am sure that Java Applets can be used for this too – can anyone confirm this?

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Ajax and Javascript resources

Posted by on October 1, 2007 No comments

Ajax and Javascript resources

You probably remember MiniAjax about which I posted way back in March.
Well now I finally got the chance to update with two not really new, but must visit web sites. The first one is AjaxRain.com, the site dedicated to aggregating Ajax, JavaScript and RIA controls & libraries. On the web site it says that should contain 755 + Ajax/Javascript/Dhtml examples and demos to download.
logo Ajax and Javascript resources

The second one is WebAppers – Only the Best and Free Resources for Web Application Developers. This one also contains significant amount of controls and plugins segmented into different categories.
logo Ajax and Javascript resources

World of Solitaire

Posted by on August 28, 2007 1 comment

Recently I came across this piece of software, it a solitaire game build on top of YUI. It is developed by Robert Schultz and over here you can read an interview with him.
Here is the game itself.
solitaire World of Solitaire

Using ASP.NET AJAX Control Extenders in VS 2008

Posted by on August 20, 2007 No comments

Scott Guthrie again shows one of the new feature of the new Visual Studio 2008 which is the improved designer support for ASP.NET AJAX Control Extenders.

What are ASP.NET Control Extenders?

ASP.NET Control Extenders are controls that derive from the System.Web.UI.ExtenderControl base class, and which can be used to add additional functionality (usually AJAX or JavaScript support) to existing controls already declared on a page. They enable developers to nicely encapsulate UI behavior, and make it really easy to add richer functionality to an application.

The ASP.NET AJAX Control Toolkit is a great example of a project that takes advantage of this control extender functionality. It includes more than 40+ free control extenders that you can easily download and use to add AJAX functionality to your applications.

For example, let’s assume we wanted to have a textbox on a page where a user could enter a date:

step1 Using ASP.NET AJAX Control Extenders in VS 2008

If the browser has JavaScript enabled, we might want to have a nice client-side calendar date picker appear when the user sets the focus on the date textbox to help with selecting the date:

step2 Using ASP.NET AJAX Control Extenders in VS 2008

Enabling this is trivial using the ASP.NET AJAX Control Toolkit. Just add the “CalendarExtender” control that ships with it to the page and point its “TargetControlID” property at the :

step3 Using ASP.NET AJAX Control Extenders in VS 2008

The CalendarExtender now automatically emits an ASP.NET AJAX javascript client script that adds the client-side calendar behavior to the TextBox at runtime. No additional code is required.


Using ASP.NET AJAX Control Extenders in VS 2008

With VS 2005 you had to manually wire-up control extenders yourself (either via source-view or via the property grid).

VS 2008 makes it even easier to discover and attach control extenders to your controls.
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Building Ajax Applications on AIR

Posted by on August 8, 2007 No comments

Folks at ajaxian.com had this post today:

The Adobe bus tour has published some videos from the first leg of the tour.

Andre Charland spoke on how to build Ajax applications on Air. The talk has good demos and examples, such as the Salesforce.com demo.

Kevin Hoyt also gave some good JavaScript-y talks such as:

The second leg of the bus kicks off next week, and you can check out if it hits a city near you. I am hoping to be on the third leg at some point.

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VS 2008 and .NET 3.5 Beta 2 Released

Posted by on July 30, 2007 7 comments

I have been away for 10 days and during that time the new VS 2008 and .NET 3.5 Beta2. Here is what Scott Guthrie writes about this news:
You can download the Visual Studio 2008 product here. You can alternatively download the smaller VS 2008 Express Editions here.

VS 2008 and Visual Web Developer 2008 Express can be installed side-by-side with VS 2005. .NET 3.5 Beta2 also includes a go-live license which allows you to build and deploy applications into production.

Very Important: Please read my “Installation Notes” at the bottom of this blog post for a few post-installation steps you must make to ensure everything runs well. One of these steps fixes a side-by-side issue we found with ASP.NET AJAX.


Quick Tour of Some of the New Features for Web Development

Over the last few months I’ve written several blog posts that discuss some of the new improvements in this release. Below is a quick summary list of several of them that I have already published. This list is by no means exhaustive – there are a lot more things I haven’t had a chance to blog about yet (stay tuned for more posts!):

VS 2008 Multi-Targeting Support

VS 2008 enables you to build applications that target multiple versions of the .NET Framework. You can learn more about how this works from my blog post here:

VS 2008 Web Designer and CSS Support

VS 2008 includes a significantly improved HTML web designer. This delivers support for split-view editing, nested master pages, and great CSS integration. Below are two articles I’ve written that discuss this more:

ASP.NET also has a new control that I’ll be blogging about in the near future. It delivers very flexible support for data UI scenarios, and allows full customization of the markup emitted. It works nicely with the new CSS support in VS 2008.

ASP.NET AJAX and JavaScript Support

.NET 3.5 has ASP.NET AJAX built-in (and adds new features like UpdatePanel support with WebParts, WCF support for JSON, and a number of bug fixes and performance improvements). VS 2008 also has great support for integrating JavaScript and AJAX into your applications:

I will be doing a blog post in the next few days that talks more about some of the ASP.NET AJAX specific improvements, as well as how to upgrade existing ASP.NET AJAX 1.0 applications to use them.

Language Improvements and LINQ

The new VB and C# compilers in VS 2008 deliver significant improvements to the languages. Both add functional programming concepts that enable you to write cleaner, terser, and more expressive code. These features also enable a new programming model we call LINQ (language integrated query) that makes querying and working with data a first-class programming concept with .NET.

Below are some of the articles I’ve written that explore these new language features using C#:

Data Access Improvements with LINQ to SQL

LINQ to SQL is a built-in OR/M (object relational mapper) in .NET 3.5. It enables you to model relational databases using a .NET object model. You can then query the database using LINQ, as well as update/insert/delete data from it. LINQ to SQL fully supports transactions, views, and stored procedures. It also provides an easy way to integrate business logic and validation rules into your data model. Below are some of the articles I’ve written that explore how to use it:

I’ll be adding several more articles to my series above in the weeks ahead. I think you’ll find that LINQ to SQL makes it dramatically easier to build much cleaner data models, and write much cleaner data code.

Lots of other improvements

The list above is only a small set of the improvements coming. For client development VS 2008 includes WPF designer and project support. ClickOnce and WPF XBAPs now work with FireFox. WinForms and WPF projects can also now use the ASP.NET Application Services (Membership, Roles, Profile) for roaming user data. Office development is much richer – including support for integrating with the Office 2007 ribbon. WCF and Workflow projects and designers are included in VS 2008. Unit testing support is now much faster and included in VS Professional (and no longer just VSTS). Continuous Integration support is now built-in with TFS. AJAX web testing (unit and load) is now supported in the VS Test SKU. And there is much, much more…


Important Installation Notes – PLEASE READ!

There are two important things you should do immediately after installing VS 2008 and .NET 3.5 Beta2:

1) You should download and run this batch file. This takes only a few seconds to run, and fixes an issue we found earlier this week with the version policy of System.Web.Extensions.dll – which is the assembly that contains ASP.NET AJAX. If you don’t run this batch file, then existing ASP.NET 2.0 projects built with ASP.NET AJAX 1.0 and VS 2005 will end up automatically picking up the new version of ASP.NET AJAX that ships in .NET 3.5 Beta2. This will work and run fine – but cause you to inadvertently introduce a .NET 3.5 dependency in the applications you build with VS 2005. Running the batch file will change the version binding policy of the new System.Web.Extensions.dll assembly and ensure that you only use the new .NET 3.5 ASP.NET AJAX version with projects that you are explicitly building for .NET 3.5.

2) If you have ever installed a previous version of “Orcas” or VS 2008 on your machine (either Beta1 or one of the CTP versions), you need to reset your VS 2008 settings after installing Beta2. If you don’t do this, you’ll have an odd set of settings configured (some windows will be in the wrong place), and you’ll potentially see some IDE performance slowness. You can reset your settings by typing “DevEnv /resetsettings” on the command-line against the VS 2008 version of the IDE:

step1 VS 2008 and .NET 3.5 Beta 2 Released


Summary

There are a lot of new improvements and enhancements that I hope you’ll find really useful with VS 2008 and .NET 3.5. Stay tuned to my blog over the next few weeks as I’ll be posting more about some of the new features and how to get the most out of them.

Here is the original

ASP.NET, ASP.NET AJAX, Visual Studio, Silverlight and IIS7

Posted by on July 6, 2007 No comments

This is last list published by Scott, in which he presents latest articles and posts relating ASP.NET, ASP.NET AJAX, Visual Studio, Silverlight and IIS7. Check it out here, at the bottom is a link to the original:

ASP.NET

  • ASP.NET RSSToolkit 2.0 Released: One of the cool projects for ASP.NET 2.0 that was released last year was this free RSS Toolkit – which makes consuming and exposing RSS feeds in ASP.NET super easy (you can even databind any ASP.NET control against them). The team working on the CodePlex project has recently released V2 of the RSSToolkit. You can learn all about it and download it here.

  • Building a Custom Database Driven Site Map Provider: Scott Mitchell has written a great article on how to implement your own site map provider for ASP.NET that is populated from a database (instead of statically from an XML file). You can learn more about the ASP.NET 2.0 SiteMap system from this older blog post of mine here.

  • .NET DateTime and Number Format String Cheat Sheet: If you are like me, you might have trouble remembering all of the standard format strings you can pass to the String.Format() method and/or the Eval() databinding method in ASP.NET to generate the appropriate string output from a DateTime or Numeric datatype. This PDF cheatsheet is a useful one to download and save to quickly look these format strings up. John has some other really useful .NET PDF cheatsheets he has also created that you might like to download here.

  • Profile Support for ASP.NET Web Application Projects: VS 2005 Web Application Projects can’t directly access the strongly-typed ASP.NET “Profile” object that web site projects support. This VS add-in supports the ability to generate a strongly typed profile class to accomplish this. You can read this great series of posts to learn more about how to use the ASP.NET 2.0 Profile system. I have it on my list of tips/tricks posts to-do to cover using this VS add-on as well.

  • ASP.NET Photo Handler: Bertrand has posted a cool photo album HttpHandler for ASP.NET that allows you to easily drop images into a web directory and automatically generate a nice photo album of them (complete with EXIF information, stack sorting icons, etc). Might be very useful for people enjoying holidays this summer. Download the code here.

  • BlogEngine.NET: This is a new open source blog engine for ASP.NET that Mads Kristensen has helped start up, and which I’ve heard a lot of good things about. You can read about its features here, and download it here.


ASP.NET AJAX

  • ScriptDoc 1.0 Available: Bertrand Le Roy has published a cool ScriptDoc utility that extracts documentation from JavaScript files and packages it into XML that can be consumed by documentation building tools. A very useful tool as you start to build up your own JavaScript libraries.


Visual Studio

  • GhostDoc 2.1.1 Released: GhostDoc is a free add-in for Visual Studio 2005 (and now 2008) that automatically generates default XML documentation comments for code you write in C# or VB. It can automatically re-use existing documentation inherited from base classes or implemented interfaces, or generate initial documentation by deducing comments from the name and type of the member signature. You can learn more about it and download it for free here.


Silverlight

  • Silverlight Tutorials: Michael Schwarz has a great blog where he writes regularly about Silverlight. This tutorials link points to a bunch of great Silverlight content.


IIS 7

  • IIS 7.0 is now running all of Microsoft.com: One of the things we push at Microsoft is to “dogfood” our products on our high volume sites when they enter the beta cycle. As of a few weeks ago, all of the web servers running www.microsoft.com are now running on IIS7 and Windows 2008 Server Beta3. These servers host 500+ virtual roots and 350 ASP.NET applications, and handle 300,000 concurrent connections. IIS7 is going to be an awesome release.

  • IIS 7.0 on Server Core: Bill Staples blogs about some of the new IIS7 enhancements that appear with the June CTP of Windows 2008 Server. One of the big features that is now supported is the ability to install IIS7 on “server core” – which is a low footprint installation of Windows 2008 Server that lays down just the minimal footprint needed to boot (meaning no GUI shell). This lowers the resources required on servers, and even more importantly means that servers don’t need to be updated if a patch is released for a component not installed on the server (which lowers the downtime of servers). ASP.NET and the .NET Framework aren’t supported yet in server core configurations – but will be in the future.

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Updated ASP.NET AJAX Control Toolkit Release and New ASP.NET AJAX Videos/Articles

Posted by on June 26, 2007 No comments

Scott Guthrie put all these links together! Check them out here, thanks Scott!

Last week the ASP.NET AJAX Control Toolkit team released Build 10618 of the ASP.NET AJAX Control Toolkit. This fixed a few issues discovered with the release earlier this month including:

  • A fix for the Tabs naming container
  • A fix for a VS design-time dependency
  • FilteredTextBox Navigation and control key issues

This build also contains additional performance optimizations for the new “script combining” feature provided by the new ToolkitScriptManager control. This feature can help significantly improve performance for pages with multiple AJAX scripts that previously needed to be downloaded separately. David Anson has a nice blog post that talks about these improvements here.


New ASP.NET AJAX Videos

Joe Stagner has recently posted five new (free) ASP.NET AJAX videos on www.asp.net:

step1 Updated ASP.NET AJAX Control Toolkit Release and New ASP.NET AJAX Videos/Articles

You can download and watch the videos here. These new videos are available to download in a variety of video and audio formats including: WMV, Zune, iPod, PSP, MPEG-4, and 3GP.


New ASP.NET AJAX Articles

Here are a few recent ASP.NET AJAX articles you might also want to check out:

  • ASP.NET AJAX UpdatePanel Tips and Tricks: This is a great MSDN Magazine article by Jeff Prosise that covers: update highlighting, how to cancel updatepanel updates, optimizing with conditional updatepanels, and using page methods.

  • AJAX Control Toolkit Patch Utility: If you are not an official contributor to the ASP.NET AJAX Control Toolkit project, but would like to submit a bug fix or small feature into the toolkit, you can read this article to learn how to create and submit a patch to the team for them to review and potentially include.

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