Duwamish 7

Duwamish is an e-commerce site fronted by ASP.NET. Like the IBuySpy store, it is implemented in C# and Visual Basic .NET, uses output caching, accesses the database exclusively through stored procedure code, and provides an optional (but unused) XML Web service. Unlike the IBuySpy case studies, however, Duwamish is an update of a well-known Microsoft platform sample that was previously used to demonstrate the best of Windows DNA coding. As a result, Duwamish follows a more traditional multilayered design, which has both benefits and disadvantages.

In Duwamish, the Web page communicates with a business layer facade, which then interacts with a business rules layer, which ultimately uses the data access layer to send information to and from the database. This design complicates the structure of the applications, but it also allows for some intriguing possibilities. For example, the classes in the business facade layer are all remotable MarshalByRefObject types, which means they can be easily hosted on another computer if required. Duwamish also uses a "system framework" component, through which the various parts of the application access configuration information, log messages, and raise exceptions. This is similar to the facade-based designs discussed in Chapter 10.

You can download the Visual Basic version of Duwamish 7 through MSDN at http://msdn.microsoft.com/code/sample.asp?url=/MSDN-FILES/026/002/073/msdncompositedoc.xml. It includes a setup program that installs the required information in the database and configures a virtual directory for the ASP.NET front end. The Duwamish Books home page is shown in Figure 19-3.

Figure 19-3. Duwamish Books

Note

As with all MSDN pages, the URL for downloading Duwamish 7 is subject to change. If you don't find it in service or if you don't want to type in the full string, you can go to the MSDN Code Center at http://msdn.microsoft.com/code. You should be able to browse or search for the required download from there.