| ★ wanayoo — archive 1999 http://informationweek.com/700/00olfox.htm | Nouvelle recherche | Portail wanayoo |
|
|
|
September 14, 1998 FoxPro Looks Familiar Version 6.0 stays the course, but adds building blocks and catalogs By Andy Feibus 
isual FoxPro 6.0, which was released this month, doesn't add a lot of new features, but a few of them are noteworthy. In many ways, this release is similar to Visual FoxPro 5.0-including no supporting native-code compilations-except that version 6.0 adds a few tools, support for Active Documents, and some "enterprise-class" features for those users looking to distribute their VFP applications.For many people, the name "FoxPro" might conjure up dBase programming on DOS in a character-based environment using flat files. Over the past few years, Microsoft renamed the product Visual FoxPro; gave it a Windows user interface; and significantly improved support for remote databases, ActiveX controls, and the object-oriented programming paradigm. The results are impressive. You can create new objects-optionally inheriting the actions of other, existing objects-and use them in your designs. You can use the numerous wizards to create forms, reports, and database tables used by your application, or just use the application wizard to create a starter application from scratch. In short, FoxPro provides many of the development and deployment features you've come to expect from an application development product. The only feature missing is support for creating native-code compiled applications, which provide better performance for calculation-intensive operations. The biggest and best change for this release is the Component Gallery. It provides a cataloged repository for code samples, control groups, classes, forms, and such. Instead of scattering these pieces throughout your system and the network, the Component Gallery organizes them in catalogs to provide an easy way to locate both standard and user-defined classes, control groups, and other components for use in your applications. Microsoft provides predefined catalogs with Visual FoxPro 6.0, and you can create your own as well. You can add new components to a catalog easily, and components can be inserted easily-with full inheritance, including overriding inherited property values-into your application, too. This ability is similar to the Visual Component Manager that comes with the other development tools in Visual Studio 6.0, but the Component Gallery has a different user interface and supports inheritance. One problem I found with the Component Gallery, however, is that although I could create different views of my catalogs-for example, to show all components with a keyword of "button"-I couldn't work with the components within this view. Only the standard views let me actually use the components. One of the reasons the Component Gallery is so useful is the other key improvement: this release vastly extends the number of predefined classes provided with Visual FoxPro. Version 5.0 only included a few predefined classes, mostly as samples for use to create new classes. Version 6.0 includes a huge set of "foundation" classes that provide a lot of the basic functions you'll include in your applications, including dialog boxes, groups of controls for navigating tables. These classes are a huge bonus for developers looking to quickly implement new applications. Another new feature is the Coverage Profiler, a trace mechanism. Run an application or part of an application with the Profiler and it shows the lines of code executed. This feature is similar in intent to Rational Software's Visual PureCoverage, except FoxPro's implementation is significantly more limited. In version 6.0, coverage testing involves first specifying the log file to contain the coverage information, then running your application, then examining the coverage results in the Coverage Profiler tool. Although you can append additional run information to an original run's results, you can't break out different test runs as in Visual PureCoverage. The Coverage Profiler also displays statistics on each module's coverage rate and provides an overall project coverage report, but getting a customized summary report or graphical view of the test statistics isn't included. On the Web front, you can now create Active Documents from Visual FoxPro applications. Active Documents are essentially applications that display their forms in Active Document container. Once the application becomes an Active Document, you can integrate it into an intranet application, provided your users use Internet Explorer 3.0 or later. The user interface looks the same as in version 5.0, which is to say nothing at all like the user interfaces you'll find with the rest of Microsoft's development tools.
Building Tables The user interface in FoxPro 6.0 also supports OLE drag-and-drop operations, so you can now drag and drop information between a FoxPro application and another application (for example, Windows Explorer or Visual Basic) that supports OLE drag-and-drop. Also new is the ability to enforce a strict four-digit year format, so existing applications with two-digit years stored in the code will now generate a build error, notifying the developer the application is not going to be year 2000 compliant. On the "enterprise" support side, FoxPro lets you create Component Object Model objects that can now be hosted by Microsoft Transaction Server. Some of the new features added in this release of FoxPro include support for COM automation server threading and the ability of the FoxPro runtime library to properly support multiple COM servers. Both of these features will be important only if you plan to create COM servers with FoxPro or distribute your application across multiple servers using the distributed COM solution from Microsoft.
Application Modeler Except for the Component Gallery and foundation classes, Visual FoxPro 6.0 is only a small upgrade from Visual FoxPro 5.0. If you need these features, then you should definitely upgrade to the new release; if you already have an organized set of classes written, the upgrade may not make as much sense. Visual FoxPro 6.0 is certainly a possibility for new users who want an interesting programming environment that makes it easier to create new applications quickly, although other tools, including TopSpeed's Clarion 4-reviewed last week --provide a better overall development environment.
Andy Feibus is president of CustomBytes, an application development firm in Atlanta. He can be reached at amf@mindspring.com.
|
 |
|
|
