Store a calculated field value

Created by Phil Kurth, Modified on Fri, 18 Nov, 2022 at 1:30 PM by Phil Kurth

Calculated fields are designed purely for display purposes but if you find yourself needing to store the calculated value, you may use the af/form/submission hook to call and save the calculated value in an additional ACF field, as per the following example:

// Calculate the value of our calculated field named `calculated_1`
add_filter( 'af/field/calculate_value/name=calculated_1', function () {
  return af_get_field( 'number_1' ) + af_get_field( 'number_2' );
}, 10, 0 );

// Use a custom submission handler to saved the calculated field value to the database as needed.
add_action( 'af/form/submission', function ( $form, $field, $args ) {

  // If we need to run this only on a specific form, check for the form key.
  if ( $form['key'] !== 'YOUR_FORM_KEY_HERE' ) {
    return $form;
  }
  
  // If the form is creating a post and you need to store the value against the created post ID, you
  // can access the post ID on the submission array and use it as the ACF object ID.
  $acf_object_id = AF()->submission['post'];

  // Alternatively, if the form is creating a user, you can access the ID in a similar fashion to
  // build the necessary ACF object ID.
  //$acf_object_id = 'user_' . AF()->submission['user'];

  // Get the value of the calulated field
  $calculated = af_get_field( 'calculated_1' );

  // Store the value in a desired ACF field
  update_field( 'some_field_name', $calculated, $acf_object_id );

  return $form;
}, 20, 3 );