1075-1076

Previous | Table of Contents | Next

Page 1075

developer needs to reference objects that have been designed and are being coded by another developer, the only option is to export the objects requiring external references to text files and editing them with a regular text editor. This, too, can present problems, because when the objects are imported back into the environment, the scripts are compiled, and once again, all external references must be resolved. Even when programming solo, a developer can be tripped up by a single statement, such as

open(w_mdi_child); 

This statement does not work if w_mdi_child does not yet exist.

Although this constant compilation eliminates many of the bugs that crop up due to typographical and syntax errors in early phases of development, it slows the process considerably. When you are designing a PowerBuilder application, you should carefully think through a strategy for the order in which objects are constructed . Commenting out external references in the early phases of development may save time, as well.

Another disadvantage relates to the proprietary nature of the product. The database interfaces for many of the most popular RDBMSs are not shipped with the inexpensive desktop edition. Without the necessary interface, the only alternative is to use the ODBC API directly or a do-it-yourself proprietary interface (such as using Pro*C to interface with Oracle, for example). For Java connectivity, refer to Chapter 53, "Web Database Connectivity." Either alternative eliminates the possibility of going quick and dirty with DataWindows. The proprietary scripting language, although it is a very good language, can be a drawback for shops making the transition from mainframe to client/server because of the additional learning curve. Most programmers have some experience with BASIC or Pascal, but they will not have any experience with PowerScript until they use PowerBuilder.

Despite these potential drawbacks, PowerBuilder is one of the best development tools available for Microsoft Windows. Its powerful object-oriented features and extensive support for database applications make it a solid candidate for any client/server project.

Page 1076

Previous | Table of Contents | Next