Form

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4D v17.4

Form


Form -> Function result

Parameter	Type	Description
Function result	Object	Form data associated to the current form

Description

The Form command returns the object associated with the current form, if any. 4D automatically associates an object to the current form in the following cases:

the current form has been displayed by the DIALOG command,
the current form is a subform.

DIALOG form

If the current form is being displayed by a call to the DIALOG command, Form returns either an empty object, or the formData object passed as parameter to this command, if any.

Subform

If the current form is a subform, the returned object depends on the parent container variable:

If the variable associated to the parent container has been typed as an object (C_OBJECT), Form returns the value of this variable.
In this case, the object returned by Form is the same as the one returned by the following expression:
(OBJECT Get pointer(Object subform container))->

If the variable associated to the parent container has not been typed as an object, Form returns an empty object, maintained by 4D in the subform context.

For more information, please refer to the Page subforms section.

Example

In a form displaying the record of a person, a "Check children" button opens a dialog to verify/modify the names and ages of their children:

Note: The "Children" object field is represented only to show its structure for this example.

In the verification form, you have assigned some Form object properties to variables:

Here is the code for the "Check children" button:

 C_LONGINT($win;$n;$i)

 C_BOOLEAN($save)

 ARRAY OBJECT($children;0)

 OB GET ARRAY([Person]Children;"children";$children) //get the children collection

 $save:=False //initialize the save variable

 

 $n:=Size of array($children)

 If($n>0)

    $win:=Open form window("Edit_Children";Movable form dialog box)

    SET WINDOW TITLE("Check children for "+[Person]Name)

    For($i;1;$n) //for each child

       DIALOG("Edit_Children";$children{$i}) //displays dialog filled with values

       If(OK=1) //the user clicked OK

          $save:=True

       End if

    End for

    If($save=True)

       [Person]Children:=[Person]Children //forces object field update

    End if

    CLOSE WINDOW($win)

 Else

    ALERT("No child to check.")

 End if

Note: This example requires that object notation be enabled in the database (see Compatibility page).

The form displays information for each child:

If values are edited and the OK button is clicked, the field is updated (the parent record must be saved afterwards).