When building WAP applications, you have to remember that the client device will probably have a very small screen. If you are trying to design a large form, you will want to specify which form elements are kept together on one screen. The fieldset tag groups together form elements, and the microbrowser will try to keep groups on one screen. The WML Specification provides an excellent example.
The postfield element allows you to POST a field name and value submission in a URL request, without it having been visible on the posting form. The WML Specification provides an example of postfield in use.
In GSM, WAP can be run over the Short Message Service (SMS) or via Circuit Switched Data (CSD). The latter provides much greater bandwidth.
Yes! And be careful, because WAP v1.1 uses lower-case tags.
One of the layers of the WAP stack, known as WTLS, provides encryption and authentication for server-to-client security. This prevents fraudulent access to WAP transactions and opens the way for e-commerce- and intranet-type applications.
Yes, it can do. GPRS is a new over-the-air service that transmits data packets to hand-held devices. It will allow much faster WAP transmission than currently available over SMS or CSD when using GSM.
Yes. You can create WML in exactly the same way that you create HTML. If you have written your servlets to produce WML, just remember to set the MIME type correctly:
No. Not necessarily. If you want to serve up simple WAP content, you can use an existing web server (and just change the MIME types). A mobile will connect to your server through a WAP gateway located in their mobile operator's network.
However, there are some advantages to hosting your applications on a WAP gateway - since it is part of the mobile network. You can have access to information like the mobile's number, identity, and possibly location.
In theory, yes. However, not all WAP handsets will support them. Another approach to session management is to use hidden form fields containing session identifiers (either in the header using the 'POST' method or in the URL using the 'GET' method.)