dlgEvent_record_BeforeDelete

Function called by dialog code event before user deletes a row.

Syntax

PUBLIC FUNCTION dlgEvent_record_BeforeDelete( 
   dlg ui.DIALOG, 
   uiMode SMALLINT,
   dlgCtrlInstruction libdbappEvents.DlgCtrlInstruction_Type)
  RETURNS (libdbappEvents.DlgCtrlInstruction_Type)
The function parameters are:
  1. dlg. This is a ui.DIALOG object referencing the current dialog. The dialog can implement an INPUT, INPUT ARRAY, DISPLAY ARRAY, MENU, or CONSTRUCT. For more information, see The Dialog class in Genero Business Development Language User Guide.
  2. uiMode. This is an integer value defining the current mode or state in relation to user action in the dialog, form, or application. Modes are defined as constants in the libdbappFormUI file in the libdbapp library.
    Table 1. UI modes
    Description Applies to ... Constant Value
    Display DISPLAY ARRAY C_MODE_DISPLAY 1
    Modify INPUT \ INPUT ARRAY C_MODE_MODIFY 2
    Add INPUT \ INPUT ARRAY C_MODE_ADD 3
    Search CONSTRUCT C_MODE_SEARCH 4
    Empty MENU C_MODE_EMPTY 5
    Exit form The form C_MODE_EXIT_FORM 6
    Exit app The app C_MODE_EXIT_APP 7
    Undefined All (array, form, or app) C_MODE_UNDEFINED 0
  3. dlgCtrlInstruction is a libdbappEvents.DlgCtrlInstruction_Type defining the DIALOG control instruction. Instructions available in the function are shown in the table.
    Table 2. Dialog control instructions
    Description Constant Value
    Accept dialog ACCEPT_DIALOG 1
    Continue dialog CONTINUE_DIALOG 2
    Exit dialog EXIT_DIALOG 3
    Exit menu EXIT_MENU 4
Returns a dialog instruction value defined by the libdbappEvents.DlgCtrlInstruction_Type type.

Usage

When you select the Before Delete Row property for the creation of the event, a function shell is created. Enter your code in the function.

This function is called when a user tries to delete a row in a dialog controlling an INPUT ARRAY. You can cancel the delete operation if the user is not allowed delete rows in the database, or if a database error occurs. The operation is canceled with the instruction to CONTINUE_DIALOG returned in dlgCtrlInstruction.

Example: Before Delete

This example uses the Before Delete Row code event for the Account form in the OfficeStore demo.

In this example if this user is not allowed to insert rows, an error is raised and the insert is canceled in the dlgCtrlInstruction instruction returned.

PUBLIC FUNCTION dlgEvent_recAccount_BeforeDelete(dlg ui.DIALOG, uiMode SMALLINT,
      dlgCtrlInstruction libdbappEvents.DlgCtrlInstruction_Type)
    RETURNS (libdbappEvents.DlgCtrlInstruction_Type)
  
    DISPLAY "dlgEvent_recAccount_BeforeDelete (Row scope) is raised"

    IF NOT user_can_delete THEN
       ERROR "You are not allowed to delete rows"
       LET dlgCtrlInstruction = libdbappEvents.CONTINUE_DIALOG
    END IF      
    
    DISPLAY "dlgEvent_recAccount_BeforeDelete (Row scope) is exited"    
    RETURN dlgCtrlInstruction
END FUNCTION