Introduction to Genero BDL programming / Genero BDL concepts |
The code to control application forms is written in single statements that perform the common tasks associated with such applications.
These interactive statements allow the program to respond to user actions and data input.
The DISPLAY BY NAME / TO instruction allows you to display program variable data in the fields of a form and continue the program flow without giving control to the end user.
The MENU instruction is typically used in text user interface programs to handle user choices and activate a specific function of the program.
The INPUT instruction is designed for simple record input. It enables the fields in a form for input, waits while the types data into the fields, and proceeds after the user accepts or cancels the dialog.
The DISPLAY ARRAY instruction is used to browse a list of records. It allows the user to view the contents of a program array of records, scrolling the record list on the screen and choosing a specific record. DISPLAY ARRAY implements by default a read-only list of records, but can be extended to become a modifiable list with list modification triggers such as ON INSERT.
The INPUT ARRAY instruction supports record list input. It allows the user to alter the contents of records of a program array, and to insert and delete records.
The CONSTRUCT instruction is designed to let the user enter search criteria for a database query. The user can enter a value or a range of values for one or several form fields, and your program looks up the database rows that satisfy the requirements.
The DIALOG statement allows you to combine INPUT, DISPLAY ARRAY, INPUT ARRAY and CONSTRUCT functionality within the same form.