Progress
Programming
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Advantages of Persistent Procedures
Persistent procedures promote modular application design and development by more easily allowing you to distribute functionality among several procedures. For example, you might build a persistent procedure that provides access to a database through a set of local buffers that it otherwise hides from the rest of the application. Or your persistent procedure might create and manage its own windows while allowing independent access (non-modal access) to other windows in your application. Aside from helping to manage functionality, the additional modularity also helps to avoid hitting r-code segment limits.
Thus, creating a persistent procedure whose context you access through internal procedures provides the most effective means to achieve encapsulation in Progress. For more information on using internal procedures to promote encapsulation, see the "Internal Procedures" section.
You can also use a persistent procedure to create multiple versions of the same context. Each time you call a persistent procedure, it creates a separate instance of its context. Your application (and user) can access and manage each context independently from the others. If your persistent procedure manages its own windows, you can use this feature to provide some (but not all) of the capabilities of the Microsoft multiple document interface (MDI).
For more information on using persistent procedures to manage multiple windows, see Windows."
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