Beginning Web Development, Silverlight, and ASP.NET AJAX

CHAPTER 13
Ajax Scripts and Services
As you saw in Chapter 12, ASP.NET AJAX has both server and client components. You
saw how you use the ScriptManager to create a service reference so that a web service
can be accessed directly from JavaScript.
In this chapter, you will look at some of the server controls and their supporting
classes in some more detail. In particular, you will look at the ScriptManager control and
how it can be used to link your server and client applications neatly. It enables ASP.NET
AJAX applications to work within the browser, along with its partner control, the Script-
ManagerProxy. You’ll see how to deliver custom scripts to the browser, how to manage
partial page rendering, and how to access web services directly from script.
You’ll build on this to look at how Ajax applications can access ASP.NET services such
as memberships and profiles, building out a role-based secured site in ASP.NET and then
seeing how this can be accessed from JavaScript as well as ASP.NET.
The ScriptManager Class
The ScriptManager class is designed to manage the ASP.NET AJAX script libraries, all the
script files that you use within your application, and proxy class generation for web services.
In addition, it supports the UpdatePanel, UpdateProgress, and Timer controls to
perform their partial page refreshing and timing functions. These controls will not work
unless a ScriptManager is present. Finally, it offers the JavaScript classes that are necessary
to access authentication and profiling services.
Partial Page Rendering
As you saw in the previous chapter, by storing page content and controls within Update-
Panels, partial page updates become possible. This is managed by the ScriptManager
component, which delivers scripts that interact with the page life cycle (you can see this
in more depth in Chapter 3). The ScriptManager has an EnablePartialRendering property
that allows you to override this. By default, it is set to true, meaning that partial rendering
is automatically enabled, and all UpdatePanel controls will refresh upon postback (but
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