Latest Articles: AJAX

Last week I stumbled upon some pretty neat functionality of the out-of-the-box List View Web Part in SharePoint 2010: the AJAX Options. When you add a Web Part from the List and Libraries category (that basically shows you every List and Document Library you have on the SharePoint site) behind the scenes the Data View Web Part is being used to display the List or Document Library data.

Interesting, with MOSS 2010 you can make some controls just AJAX enabled with a mouse click.

Originally the Autocomplete Extender lacked very important functionality - ability to operate with key-value pairs. If you think about that, the Google search auto complete serves its purpose - the resulting string IS the value which is important for the postback, but it is scarcely the case for the 98% of non-search applications. We need control to mimic dropdown list - so gimme ya money let me keep the value for the entered text! Such a functionality was added some time ago but regretfully the feature was left undocumented.

The right way to have a key / value combination on an AutocompleteExtender (asp .net AJAX toolkit).

Great article, easy to apply in your real code.

It’s important to remember that a partial postback is just that: A postback.

The UpdatePanel’s way of abstracting AJAX functionality behind standard WebForm methodology provides us with flexibility and familiarity. However, this also means that using an UpdatePanel requires careful attention to the ASP.NET Page Life Cycle.

When you start developing using Microsoft AJAX ASP .net, you can think that Partial Rendering and UpdatePanels are the magic soluton to all the problems, Watch out !! Is quite important to know the inners of this technology in order to know in which scenario you can use them.

Beware... everything will perform fast in your local development environments, headaches come when you move to a production enviroment...

Now, after the very futile example which accompanied the introduction to JavaScript Object Notation in my last post (by the way, I forgot to mention that this is what the fancy acronym stands for, but I'm sure you already knew that), let's go straight to the fun part, and see how we can leverage the flexibility of JSON (and ASP.NET AJAX, of course) to achieve some less trivial result. When developing a web application, we often need to aggregate data from different sources. You might argue this is no big news, as we've all used web services in a way or the other, and "mashup" is surely not an uncommon word these days. But probably, for most of us, the natural way to think of data returned from a web service call is XML. But XML is not exactly the easiest thing to parse on the client, nor a very succinct format. That's why a number of JSON web services have flourished lately. Probably the first that comes to mind is Google Maps' Geocoder (see here), but there are a lot more. If you are looking for inspiration you can have a look at xmethods. But today, we are focusing on some very, very interesting web methods kindly offered by Geonames.

Quite good stuff, AJAX ASP .net + JSON at low level.

Most of us are used to let the AJAX ASP .net framework to do all the magic for us (JSON serialization / deserialization) in this post series you will learn the internals, and how to do it by your self, interesting thing to, for instance, serialize an array on a hidden field

Microsoft has premier partners to provide hosted ASP.NET services.

If you are looking for ASP .net hosting,this can be a good starting point, it lists Microsoft partners that offers ASP .net and AJAX hosting

You can check and compare prices and conditions

It does not guarantee the best hosting for your site, but at least you can get an idea of costs and features

When rolled into the page life cycle of an ASP.NET WebForm, that red bar is one of your application’s greatest enemies. No matter how well you optimize the rest of the page, even one slow task can become the sole factor determining a user’s perception of the entire page’s performance.

In this post, I’m going to show you one way to circumvent that problem. By placing ancillary content in user controls and delaying their load until the core page content has been displayed, you can drastically improve perceived performance.

Simple and nice sample about how to combine javascript calls to server side web services /script services in order to get an HTML and inject it using javascript / DOM inside a DIV using the property innerHTML.

If you just want to show readonly data this solution is excellent, users can keep on working on the page and once you get the info it will be loaded in background, if it's something that the users need to edit and post, things get a bit more difficult

In my previous column, I discussed the technologies on which AJAX relies, how you can create custom AJAX scripts to perform asynchronous postbacks, and productivity gains that the ASP.NET AJAX Extensions provide in general. In this column, I'll focus on ASP.NET AJAX configuration entries in web.config as well as on the role new HttpHandler and HttpModule classes play in AJAX-enabling Web sites.

Interesting info about how to play with web.config settings on AJAX, no more "blac magic" on such settings :-).

I've tried to investigate slow load of UpdatePanel. It works quick enough in FireFox, slow in IE 7 and even more slower in IE6.

A must read AJAX ASP .net trouble shooter bunch of links

How to play with compression, issues with IE6,issues with UpdatePanel, and magic web.config settings that will boost up you AJAX ASP .net application performance (compression, compilation debug, ...)

Microsoft’s recent announcement that ASP.NET will soon get an alternate engine in the ASP.NET Model View Controller framework (MVC-see last month’s editorial) has brought out some renewed discussion of the merits and shortcomings of Web Forms and the potential need for an alternate mechanism of building Web applications that provide a closer and purer model to raw Web development. This is true especially in light of the different development style that AJAX/Web 2.0 applications are introducing and some of the complications that it raises with the Web Forms development lifestyle.

Ms is going to release this year their implementation of the MVC pattern... this means: do not use web forms anymore, do not use updatepanel or partial rendering, do not use viewstate... do not use anything that can postback :-).

Are Web forms dead? Do Web forms sucks? What are the advantages and drawbacks?

Quite interesting topic and article.

ViewState is a hugely useful feature of ASP.NET, but it's easy to misuse. It's also a little difficult to apprehend for ASP.NET beginners as it's working behind the scenes. The only thing you see at first is this huge blob on your page source.

Viewstate plus UpdatePanel: performance killer, sucks, slow pages, ...

Well, yes... UpdatePanel sends the full viewstate on each request, if you have a huge viewstate you will have a lot of problems (I have seen 1 Mb and 2 Mb pages due to ViewState, think about that big chunk travelling on every single partial rendering post).

Good news are... you don't need to rewrite your app using Script Services / Web Services (a bit complex), you can just disable the ViewState control by control and keep that data to bind in session, by using that you can reduce the ViewState to the max (and reduce the cases where you need to use Script Services), the most usual performance killer is the combination of GridView + ViewState.

One of the selling points of the Microsoft® .NET Framework is that it makes programming easier—not just Web programming, but application programming in general. Few would argue that it doesn't live up to the hype. The .NET Framework Class Library (FCL), which provides the API that managed applications write to, is so rich and diverse that tasks requiring hundreds of lines of code in unmanaged applications are often accomplished with just one or two lines of managed code. If you don't believe it, compare a Windows®-based app that displays a JPEG with one that does the same using the .NET Framework (see http://samples.gotdotnet.com/quickstart/ winforms/doc/WinformsGDIPlus.aspx). With such a rich class library to fall back on, you might be misled into believing that the .NET Framework presents fewer opportunities for clever coders to do great things. On the contrary, the sheer size of the .NET Framework means that nuggets of opportunity are everywhere. To illustrate, here are five little gems to help ASP.NET programmers code their way to programming excellence. They're from my personal grab bag of favorite ASP.NET programming tricks. I think you'll find them as useful as I do.

The most interesting part of this article is how to make an image "live / refresh" without having to perform a full postback.

Imagine that you have chart bar (displayed as a fixed image, dynamically generated on the server side), and you let the user modify values using textboxes, you can just pickup the values of this boxes and using DOM/DHTML/Javascript change the URL of the image to a new one where you specify the new parameter values. You can do that implementing on the server side a custom HTTP Handler.

Very interesting, approach, it would help you to add AJAX like style to your site, without having to put lot of effort on it.