Formula from string

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4D v19.8

Formula from string


Formula from string ( formulaString ) -> function result

Parameter	Type	Description
formulaString	Text	Text formula to be returned as object
function result	Object	A native object containing the formula

Description

Formula from string creates a formula object based upon the formulaString. formulaString can be as simple as a single value or complex, such as a project method with parameters.

This command is similar to Formula, except that it handles a text-based formula. In most cases, it is recommended to use the Formula command. Formula from string should only be used when the original formula was expressed as text (e.g., stored externally in a JSON file). In this context, using token syntax is highly advised (see the Using tokens in formulas page and the Parse formula command).

Note: Because local variable contents can not be accessed by name in compiled mode, they can not be used in formulaString. An attempt to access a local variable with Formula from string will result in an error (-10737).

Example

The following code:

 C_TEXT($textFormula)

 C_OBJECT($f)

 $textFormula:=Request("Please type a formula")

 If(ok=1)

    $f:=Formula from string($textFormula)

    ALERT("Result = "+String($f.call()))

 End if

will create a dialog accepting a formula in text format,

and execute the formula: