xHarbour Reference Documentation > Function Reference

GuiGetPrevalidate()

Validates data before editing.

Syntax

GuiGetPreValidate( <oGet>, <oControl>, [<oGetMsg>] ) --> lCanEdit

Arguments

<oGet>

This is a Get object that is about to receive input focus.

<oControl>

This ia an additional text mode Control object associated with the Get object, such as a HBCheckBox() or HBListBox() object.

<oGetMsg>

Optionally, a GetMssgLine() object can be specified. It displays a message associated with <oGet> in the status line.

Return

The function returns .T. (true) if <oGet> may receive input focus, otherwise .F. (false) is returned.

Description

GuiGetPreValidate() is a utility function of the Get system used for validating if a Get object may receive input focus. It is automatically called within the Get system while READ is active. The rules for pre validation are defined with the WHEN option of the @...GET command, or via a code block assigned to oGet:preBlock. When pre validation fails, the next Get is searched that may receive input focus, and <oGet>, or its associated control, does not receive focus.

Note:  the prefix Gui comes from Clipper 5.3 and may be misleading. It has nothing to do with a Graphical User Interface. All Gui functions of the Get system operate with Get objects associated with text mode controls that mimick true GUI controls, such as menus, check boxes or radio buttons, for example.

Info

See also:	@...GET, Get(), GuiGetPostValidate(), READ
Category:	Get system
Source:	rtl\getsys.prg
LIB:	xhb.lib
DLL:	xhbdll.dll