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Chapter 1: Social Computing
based on the changes of the page, the entire page must be submitted to the server. Then it is re-rendered
to the end user once more. Microsoft realized this would be a problem for rich clients like Outlook Web
Access (OWA), so it created an ActiveX control called the XMLHttpRequest object. Eventually, other
browsers added this capability to their browsers as dynamic sites, and data was becoming more popular
as a way to render a web page. This technology has essentially replaced the original XMLHttpRequest
technology that is now called AJAX.
AJAX has become popular with social computing applications, based on how dynamic the data is and
how often the data changes. To help programmers manage the ever-changing data, AJAX allows the
developer to either update data that might have been requested on a page, but doesn’t require a full-page
refresh or can be used to load a page while making a call to a data service that may take longer to load.
This gives the illusion that the page renders quickly even if all of the data for that page was not ready
prior to loading the page. An example of how these callbacks are made in SharePoint 2007 can be seen in
the RSS feed or the usage reports that are generated, as seen in Figure 1-9.
Figure 1-9
This new technology really gives developers the power to build amazingly full interactive sites. Microsoft
noticed that this technology was so helpful that it created Microsoft ASP.NET AJAX. Microsoft has even
included Microsoft ASP.NET AJAX into the ASP.NET 3.5 as part of the .NET Framework installation.
Because SharePoint is built on ASP.NET 2.0, Microsoft ASP.NET AJAX is not part of the default instal-
lation. It can still be downloaded and installed separately for ASP.NET 2.0 and SharePoint 2007. To help
get developers started, community members like Daniel Larson created open source toolkits known
as the SharePoint AJAX Toolkit. When building rich applications using the Microsoft ASP.NET AJAX
Framework, it is important to make sure that it is installed on all of the SharePoint Web Front End (WFE)
servers prior to deploying it to production. However, developers could simply use the built-in method
calls to the XMLHttpRequest, which never went away despite the introduction of AJAX, and related
objects using JavaScript to avoid the need to deploy or install any additional AJAX frameworks on
servers.
Silverlight
JavaScript and AJAX provide powerful data-driven web pages, but people are increasingly looking for
extremely rich and interactive sites. For years, Abode Flash has answered this need for rich interactivity.
Flash is an animation-heavy programming environment that requires a unique set of skills to work
with. To provide .NET developers with tools for performing this rich set of functionality, Microsoft
introduced a technology called Silverlight, allowing developers to create powerful user interfaces using
an XML-based language called XAML, JavaScript, AJAX, and .NET. Silverlight has been quickly growing
and has become an adopted technology in that it is similar to Flash yet is accessible to .NET developers.
Figure 1-10 shows one of Microsoft examples for SharePoint and Silverlight.
Microsoft has now created a set of recommendations for using Silverlight with SharePoint called
the Microsoft Silverlight Blueprint for SharePoint. These guidance packages called Software +
Services Blueprints have a number of compelling scenarios that are worth investigating. The
Software + Services Blueprints will have many scenarios like Outlook and SharePoint. Here is an
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