Executing form-level validation rules

Implicit validation rule checking

The DIALOG instruction automatically executes form-level validation rules in the following cases:

• The NOT NULL attribute is satisfied if a value is in the field. NOT NULL is checked:
  • when the user moves to a different row in a list controlled by an INPUT ARRAY; However, if the row is temporary and none of the fields is touched, the attribute is ignored.
  • when focus leaves the sub-dialog controlling the field;
  • when NEXT FIELD gives the focus to a field in a different sub-dialog than the current sub-dialog.
  • when the DIALOG instruction ends with ACCEPT DIALOG.
• The REQUIRED attribute is satisfied if the field modification flag is true, if a DEFAULT value is defined, or if the WITHOUT DEFAULTS option is used. REQUIRED is checked:
  • when the user moves to a different row in a list controlled by an INPUT ARRAY; However, if the row is temporary and none of the fields is touched, the attribute is ignored.
  • when focus leaves the sub-dialog controlling the field;
  • when NEXT FIELD gives the focus to a field in a different sub-dialog than the current sub-dialog.
  • when the DIALOG instruction ends with ACCEPT DIALOG.
• The INCLUDE attribute is satisfied if the value is in the list defined by the attribute. INCLUDE is checked when the target program variable must be assigned. This happens:
  • when UNBUFFERED mode is used, focus is in the field, and an action is invoked;
  • when the focus leaves the field;
  • when the user moves to a different row in a list controlled by an INPUT ARRAY; However, if the row is temporary and none of the fields is touched, the attribute is ignored.
  • when focus leaves the sub-dialog controlling the field;
  • when NEXT FIELD gives the focus to a field in a different sub-dialog than the current sub-dialog.
  • when the DIALOG instruction ends with ACCEPT DIALOG.

Automatic validation occurs when the focus leaves a sub-dialog of the DIALOG instruction.

Performing validation rules explicitly

The DIALOG instruction can be used as in singular interactive instructions, with the typical OK / Cancel buttons (i.e. accept / cancel actions) to finish the instruction. This lets the user input or modify one record at a time, and program flow must reenter theDIALOG instruction to edit or create another record. To implement this, you can use the default behavior of the DIALOG instruction, and have it execute the form-level validation rules automatically when focus is lost for a sub-dialog or when leaving the dialog with ACCEPT DIALOG (raised by the OK button). However, you may want to stay in theDIALOG instruction and let the user input / modify multiple records. In this case, you need a way to execute the form-level validation rules defined for each field, before saving the data to the database. Form-level validation rules are defined by the NOT NULL , REQUIRED and INCLUDE attributes.

   ON ACTION save 
      IF DIALOG.validate("cust.*") < 0 THEN
        CONTINUE DIALOG
      END IF
      CALL customer_save()

This method automatically displays an error message and registers the next field in case of error. It is mandatory to execute a CONTINUE DIALOG instruction if the function returns an error.