MSDN Magazine - June 2008 - (Page 33)

other tasks while it retrieves stock quotes and the service call is not aborted if the user clicks to start some other task. What’s the point? Remember that with partial rendering, you can only have one request pending at a time per session—just like in a normal non-AJAX page. Of course, you can have any number of simultaneous calls if you control them directly through XMLHttpRequest. Furthermore, if you make direct service calls, you have no view state around and no worries about keeping it consistent across multiple partial rendering calls (which is the real reason why the partial rendering implementation prevents you from executing concurrent operations). The HTML Message Pattern To top off this column, let me just make a quick comment on another pattern that really deserves more attention in a future column—it’s called the HTML Message pattern. The goal of the HTML Message pattern is to have the server generate blocks of HTML markup to be displayed in the browser. As you can see, it falls somewhere between partial rendering and other models for building true AJAX applications. How would you use this pattern? One possible implementation The point of the HTML Message pattern is to have the server generate blocks of HTML markup to be displayed in the browser. would be to make a call to a remote URL (either a service or an ad hoc HTTP handler) and receive an HTML snippet ready for display. Note that it generates more traffic than plain service calls but also less traffic than partial rendering. On the server, you can use fresh instances of server controls (no view state) to assemble any output you need, styled as you like. I’ll return to this pattern in a future column. In the meantime, remember that when you’re working with ASP.NET AJAX, you need programming tools to define an AJAX service layer and call it from the client browser. In addition, you need powerful tools to manipulate data on the client effectively, such as JavaScript-based data binding and templates. Hopefully when you take a look at the sample implementation of the BST AJAX pattern I presented in this column and compare it to solutions based on partial rendering, you will inevitably come to the same conclusions that I did. DINO ESPOSITO is the author of Programming ASP.NET 3.5 Core References. Based in Italy, Dino is a frequent speaker at industry events worldwide. You can join his blog at weblogs.asp.net/despos. NCache TM Clustered Object Cache for .NET Boost your .NET application performance! If your .NET application runs in a server-farm and has large number of users, then use NCache to boost its performance and scalability. NCache is an extremely fast distributed object cache for .NET. Enterprise Distributed Object Cache Cache data, reduce database trips, and boost performance Scale up thru Replicated, Partitioned, and Client Cache topologies Distributed ASP.NET Session Cache Faster & more scalable session storage Integrate without any code change Distributed ASP.NET Output Cache Cache rendered pages and serve content without re-rendering Integrate without any code change Ph: +1-925-236-3830 msdnmagazine.com Download FREE Trial www.alachisoft.com June 2008 33 http://weblogs.asp.net/despos http://www.alachisoft.com http://www.alachisoft.com

Table of Contents Feed for the Digital Edition of MSDN Magazine - June 2008

MSDN Magazine - June 2008 Contents Toolbox CLR Inside Out Cutting Edge Patterns In Practice SAAS Concurrency Robotics Form Filler GUI Library Service Station Foundations Windows With C++ Concurrent Affairs Going Places { End Bracket }

MSDN Magazine - June 2008

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