| Usage / CONSTRUCT control blocks | |
A BEFORE FIELD block is executed each time the cursor enters into the specified field, when moving the focus from field to field. The BEFORE FIELD block is also executed when using NEXT FIELD.
When using the default FIELD ORDER CONSTRAINT mode, the dialog executes the BEFORE FIELD block of the field corresponding to the first variable of the CONSTRUCT, even if that field is not editable (NOENTRY, hidden or disabled). The block is executed when you enter the dialog. This behavior is supported for backward compatibility. The block is not executed when using the FIELD ORDER FORM.
Keep in mind that with the FIELD ORDER FORM mode, for each dialog executing the first time with a specific form, the BEFORE FIELD block might be invoked for the first field of the initial tabbing list defined by the form, even if that field was hidden or moved around in a table. The dialog then behaves as if a NEXT FIELD first-visible-column would have been done in the BEFORE FIELD of that field.