FORM Event

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4D v20 R7

FORM Event


FORM Event -> Function result

Parameter	Type	Description
Function result	Object	Event object

Description

FORM Event returns an object containing information about the form event that has just occurred. Usually, you will use FORM Event from within a form or object method.

Returned object

Each returned object includes the following main properties:


Property	Type	Description
objectName	text	Name of the object triggering the event - Not included if the event is triggered by the form
code	longint	Numeric value of the form event. See Form event code
description	text	Name of the form event (e.g. "On After Edit").

For example, in the case of a click on a button, the object contains the following properties:

{
"code":4,
"description":"On Clicked",
"objectName":"Button2"
}

The event object can contain additional properties, depending on the object for which the event occurs. For eventObj objects generated on:

List box or list box column objects, see the list box documentation on developer.4d.com.
4D View Pro areas, see On VP Ready form event.

Note: If there is no current event, FORM Event returns a null object.

Example 1

You want to handle the On Clicked event on a button:

 If(FORM Event.code=On Clicked)

    ...

 End if

Example 2

If you set the column object name with a real attribute name of a dataclass like this:

You can sort the column using the On Header Click event:

 Form.event:=FORM Event

 Case of

    :(Form event code=On Header Click)

       if(Form.event.columnName="lastname")

          Form.employees:=Form.employees.orderBy(Form.event.columnName+", firstname")

       End if

 End case

Example 3

You want to handle the On Display Details on a list box object with a method set in the Meta info expression property:

The setColor method:

 C_OBJECT($event;$0;$meta)

 $event:=FORM Event

 $meta:=New object

 

 Case of

    :($event.code=On Display Detail)

       If($event.isRowSelected)

          $meta.fill:="lightblue"

       End if

 End case

 $0:=$meta

The resulting list box when rows are selected: