15. Embedded Forms Program Structure
 
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Embedded Forms Program Structure
This chapter describes the general structure of an embedded forms-based program. Forms statements enable you to create a forms-based application. Forms can be created using Vision, ABF, or the VIFRED. (For instructions on creating forms using VIFRED, see Character-based Querying and Reporting Tools User Guide.)
The sequence of operations in a typical forms-based application is as follows:
1. Invoke the FRS. FRS controls the display whenever a form is displayed as part of an application.
2. Declare one or more forms to the FRS.
3. Display the first form, initiating a display loop that the FRS maintains while the form is displayed.
4. Offer the user a choice of different operations and specify code to be executed when these operations are chosen. When the user chooses an operation, the display loop is suspended, the specified code is executed, and then the display loop is resumed.
5. Provide the user with the option to exit the program, for example, by selecting an End or Quit operation, which terminates the display loop. When the display loop is terminated, the program can display another form or disconnect from the FRS.
You can use host language variables to specify portions of many of the forms statements. For a general discussion of how to use host language variables in an embedded SQL or QUEL program, see your query language reference guide; for information about how an individual statement uses host language variables, see the specific statement descriptions in Forms Statements. The examples in this guide use embedded SQL. For QUEL examples, see EQUEL/FORMS Examples.