WebReference.com - Part 1 of chapter 12 of XSLT Developer's Guide, from Osborne/McGraw-Hill (6/6)
XSLT Developer's Guide
We rendered the WML output using the WAP emulator from Nokia's Mobile Internet Kit 3.0. The first screen of the output is shown in Figure 12-3.
Figure 12-3 WML output from the application of Present2WML.xsl to customers.xml rendered using Nokia's WAP emulator. The actual display will automatically adjust depending on the actual form factor of the particular WAP client device much as the HTML display is automatically adjusted depending on the size of a web browser client.
When the user clicks the selected link, say the one for Powergadgets, Inc., the next card (see Figure 12-4) will be shown to the user.
Figure 12-4 The WML card with details about the customer is displayed using Nokia's WAP emulator. The user is given the options of going back to the customer list that is shown in Figure 12-3 or viewing further details about the customer by scrolling down.
If the user scrolls down to view further details about the customer, the display will change to the one shown in Figure 12-5. From there, the user can navigate back to the original list or scroll up to go back to the view in Figure 12-4.
Figure 12-5 The WML card with further details about the customer is displayed using Nokia's WAP emulator. The user can scroll back to the display shown in Figure 12-4 or click a link to go back to the customer list that is shown in Figure 12-3.
Hopefully, you will get an idea about how you can build presentation-independent n-tier applications aimed at a variety of clients. Given the scope of this book, we focused on demonstrating the use of XSLT to transform the output for different clients such as a web browser or a WAP microbrowser. Be aware, though, that designing applications for WAP clients requires careful consideration, and for a detailed treatment of this topic you should consult a book specializing in WAP applications. Here, however, are a few key considerations.
First, the form factors are much smaller than for PCs, so you have to decide carefully what to display to the user target audience. Second, the form factors vary widely across WAP devices, so you will have to test the application extensively to ensure that your user population using a multiplicity of the devices can see what you intended for them to see. Last, the data transfer rate to the WAP-enabled device is quite restrictive today, so you will have to organize the information to be sent in small packets. Developers' kits may provide some help in this regard: for example, Nokia's Mobile Internet Kit 3.0 used for the examples here will display a warning if the compiled byte code of the resulting WML file exceeds the suggested size of 1,397 bytes, since a large output may not be displayed correctly on some WAP devices available on the market.
Created: May 28, 2002
Revised: May 28, 2002