Web modules are the basic building block of WebSnap applications. Every WebSnap server application must have at least one Web module. More can be added as needed. There are four Web module types:

• Web application page modules (TWebAppPageModule objects)
• Web application data modules (TWebAppDataModule objects)
• Web page modules (TWebPageModule objects)
• Web data modules (TWebDataModule objects)

Web page modules and Web application page modules provide content for Web pages. Web data modules and Web application data modules act as containers for components shared across your application; they serve the same purpose in WebSnap applications that ordinary data modules serve in regular applications. You can include any number of Web page or data modules in your server application. 

You may be wondering how many Web modules your application needs. Every WebSnap application needs one (and only one) Web application module of some type. Beyond that, you can add as many Web page or data modules as you need. 

For Web page modules, a good rule of thumb is one per page style. If you intend to implement a page that can use the format of an existing page, you may not need a new Web page module. Modifications to an existing page module may suffice. If the page is very different from your existing modules, you will probably want to create a new module. For example, let's say you are trying to build a server to handle online catalog sales. Pages which describe available products might all share the same Web page module, since the pages can all contain the same basic information types using the same layout. An order form, however, would probably require a different Web page module, since the format and function of an order form is different from that of an item description page. 

The rules are different for Web data modules. Components that can be shared by many different Web modules should be placed in a Web data module to simplify shared access. You will also want to place components that can be used by many different Web applications in their own Web data module. That way you can easily share those items among applications. Of course, if neither of these circumstances applies you might choose not to use Web data modules at all. Use them the same way you would use regular data modules, and let your own judgment and experience be your guide. 

The following topics describe Web modules in greater detail:

• Web application module types
• Web page modules
• Web data modules