EDIT FORMULA

Home

4D v19.8

EDIT FORMULA


EDIT FORMULA ( aTable ; formula )

Parameter	Type	Description
aTable	Table	Table to display by default in the Formula editor
formula	Text	Variable containing the formula to display in the Formula editor or "" to display editor only
		Formula validated by the user

Description

The EDIT FORMULA command displays the Formula editor in order to let the user write or modify a formula. The editor contains the following on opening:

in the left list, the fields of the table passed in the table parameter,
in the formula area, the formula contained in the formula variable. If you passed an empty string in formula, the Formula editor is displayed without a formula.

The user can modify the formula displayed and save it. It is also possible to write or load a new formula. Regardless, if the user validates the dialog box, the system variable OK is set to 1 and the formula variable contains the formula defined by the user. If the user cancels the formula, the system variable OK is set to 0 and the formula variable is left untouched.

Notes:

By default, access to methods and commands is restricted for all users (except for the Designer and Administrator, in databases created with 4D 2004.4 and higher). When this mechanism is enabled, you must explicitly designate the elements that can be accessed by the users using the SET ALLOWED METHODS command. If formula calls methods that were not first “authorized” in the Formula editor using the SET ALLOWED METHODS command, a syntax error is generated and you will not be able to validate the dialog box.
The formula editor is not associated with any menu bar by default. You need to install a standard Edit menu in the calling process if you want users to be able to benefit from cut/copy/paste shortcuts in the formula editor.
The virtual structure defined by the SET TABLE TITLES and SET FIELD TITLES commands (if any) must not be used in the formula variable - nor will it be used by 4D in the returned variable. The virtual structure is only used in the Formula editor dialog box.

Keep in mind that when the dialog box is validated, the command does not execute the formula; it only validates and updates the contents of the variable. If you want to execute the formula, you must use the EXECUTE FORMULA command.

Example

Displaying the Formula editor with the [Employees] table and without a pre-entered formula:

 $myFormula:=""

 EDIT FORMULA([Employees];$myFormula)

 If(OK=1)

    APPLY TO SELECTION([Employees];EXECUTE FORMULA($myFormula))

 End if

System variables and sets

If the user validates the dialog box, the system variable OK is set to 1. If the user cancels the dialog box, the system variable OK is set to 0.