Programming Atlas

Atlas and ASP.NET

Although Atlas provides a host of benefits to the client script programmer who is creating Ajax applications, Atlas is not just about writing JavaScript and making asynchronous calls to the server. Since Atlas was created by the ASP.NET team, it’s no surprise that a prominent Atlas feature is a server framework that is integrated with (and requires) ASP.NET 2.0.

As with ASP.NET itself, one of the goals of Atlas is to deliver functionality—in this case, the benefits of Ajax—without requiring mastery of the technologies that make it work. Atlas can manage Ajax functionality for you in much the way that ASP.NET manages HTTP functionality such as postbacks, state management, and the client script required to make ASP.NET all “just work.”

In addition, on the server side, Atlas works as part of ASP.NET, and can take advantage of ASP.NET features. Atlas controls can interact with ASP.NET controls and components and with the page life cycle. You can link Atlas to ASP.NET 2.0 features like sessions and profiles, so you can take advantage of these types of capabilities on the client. Also, with Atlas and ASP.NET, you can reach beyond the page to special web services, and to web services and third-party APIs that are outside the domain and can’t be directly accessed from the client.

Key elements of the Atlas server framework include:

Atlas server controls

Provide server-based controls that resemble ASP.NET 2.0 server controls, but work with the Atlas client framework to deliver their functionality. Two controls in particular are fundamental to Atlas applications: ScriptManager, which will be discussed later in this chapter (see "The ScriptManager Control“), and UpdatePanel, which is discussed in Chapter 1.

Atlas ASP.NET services

Provide certain ASP.NET 2.0 services that are directly available to Atlas client scripts, including profiles, personalization, membership, and culture-specific services. You can expect the number of ASP.NET services available to Atlas applications to grow with future releases of Atlas.

Atlas web services bridge

Provides a way to initiate calls to services that are not located on the host web server. The web services bridge is a necessary feature for building Web 2.0-style applications (or mashups) that draw on the functionality of third-party services and their APIs. The web services bridge is covered in Chapter 10.