Developing Internet connectivity tools has become one of Microsoft's main concerns of late, and this new direction can be seen in VB 6.0. WebClasses, ActiveX Documents Generated DHTML, and Remote Data Services are some of these new technologies. The Visual Basic WebClass is Microsoft's answer to CGI. WebClasses are VB objects residing on an Internet Information Server (IIS) that respond to HTTP requests from HTML forms or other Internet-aware objects.
We thought one of the most interesting of these Internet-aware objects was the ActiveX Document. Using an ActiveX Document as a container, you can download a Visual Basic program, complete with form interface and class files, to a Web page. This ActiveX Document can then send requests to WebClasses on the IIS.
We found DHTML, on the other hand, not as much of a leap forward. The DHTML creation tools are not as full-featured as Microsoft's FrontPage product, and although it gives the VB developer a familiar framework, the additional overhead for the pages was a significant trade-off. The big weakness of both the ActiveX Document and the DHTML page is the reliance on IE 4.0. This dependence makes these technologies decent choices for in-house Microsoft-specific applications, but seem unwise for Internet applications.
The new ADO, coupled with Remote Data Services, promise a full Internet-aware client/server solution with no dependence on IIS or IE 4.0. ADO is the new catchall interface to any OLE DB data provider, including relational and nonrelational databases, e-mail, text, graphics and any existing ODBC data source. ADO is firmly embedded within Visual Studio 6.0 as the de facto data standard. VB 6.0 includes many ADO-aware objects such as the DataGrid, List and Combo Controls, which we found simple to use for local data access.
We were able to easily create data consumers and data sources for use with ADO. This new data technology is one of the bright and shining promises of Visual Studio and VB in particular. But the developer should beware, for all great things come with a price. In this case the price is diligence. Remoting ADO RecordSets via the Internet was not well-documented and quite complicated. We would strongly recommend Microsoft's Web site and the Data Access SDK as a place to start.
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