bookmark_bordergform_calculation_formula

Description

This filter can be used to dynamically modify the formula of a number field calculation or calculated product field.

Usage

The gform_calculation_formula filter has both a JavaScript version and a PHP version. Both versions should be used.

The JavaScript version only overrides the calculation formula on the front-end.

gform.addFilter( 'gform_calculation_formula', function( formula, formulaField, formId, calcObj ) {
    // do stuff

    return formula;
} );

The PHP version overrides the calculation formula when the calculation is rerun during submission using the field values saved in the entry.

add_filter( 'gform_calculation_formula', function( $formula, $field, $form, $entry ) {
    // do stuff

    return $formula;
}, 10, 4 );

JavaScript Version

Parameters

  • formula string

    The calculation formula.

  • formulaField JavaScript Object

    The current calculation field object. e.g.

    {"field_id":3,"formula":"{:1}+{:2}","rounding":""}

  • formId integer

    The ID of the form in use.

  • calcObj JavaScript Object

    The calculation object.

JS Example

gform.addFilter( 'gform_calculation_formula', function( formula, formulaField, formId, calcObj ) {
    if ( formId == '10' && formulaField.field_id == '3' ) {
        formula += '+5';
    }
    return formula;
} );

Placement

Your code snippet can be placed in a HTML field on your form or in a theme custom JavaScript file.

Source Code

This filter is located in js/gravityforms.js

PHP Version

Parameters

  • $formula string

    The calculation formula.

  • $field Field Object

    The calculation field currently being processed.

  • $form

    The form currently being processed.

  • $entry Entry Object

    The entry currently being processed.

PHP Example

add_filter( 'gform_calculation_formula', 'change_formula', 10, 4 );
function change_formula( $formula, $field, $form, $entry ) {
    if ( $form['id'] == 10 && $field->id == 3 ) {
        $formula .= '+5';
    }

    return $formula;
}

Placement

This code should be placed in the functions.php file of your active theme.

Source Code

This filter is located in GFCommon::calculate() in common.php