Gravity Forms IBAN

gform-iban.php

<?php
/*
Plugin Name: Gravity Forms IBAN
Plugin URI: https://wordpress.org/plugins/gravity-forms-iban/
Description: Adds an IBAN mask and IBAN validation to Gravity Forms.
Author: Admium and Jeroen Schmit, Slim & Dapper
Version: 1.0
Author URI: www.admium.nl
GitHub Plugin URI: AdmiumNL/adm-gravity-iban
*/

add_action( 'init', 'gform_iban_init' );

function gform_iban_init() {
	if ( class_exists( 'GFForms' ) ) {
		add_filter( 'gform_input_masks', 'gform_iban_add_mask' );
		add_filter( 'gform_input_mask_script', 'gform_iban_set_mask_script', 10, 4 );
		add_filter( 'gform_validation', 'gform_iban_validation' );
	}
}

/**
 * Adds the IBAN mask to the built-in input masks that are displayed in the Text Field input mask setting.
 *
 * @param array $masks Current list of masks to be filtered
 *
 * @return    array            The list of masks, including the IBAN mask.
 * @since    1.0
 */
function gform_iban_add_mask( $masks ) {
	$masks['IBAN'] = 'iban';

	return $masks;
}

/**
 * Sets the IBAN mask script for a field.
 *
 * @param string $script The script (including <script> tag) to be filtered.
 * @param int $form_id ID of current form.
 * @param int $field_id ID of current field.
 * @param string $mask Currently configured mask.
 *
 * @return    string              The updated script.
 * @since    1.0
 */
function gform_iban_set_mask_script( $script, $form_id, $field_id, $mask ) {

	// Mask: 2 letters / 2 numbers / max 32 numbers or letters
	if ( 'iban' == $mask ) {
		$script = "jQuery('#input_{$form_id}_{$field_id}').mask('aa99 ?**** **** **** **** **** **** **** ****');";
	}

	return $script;
}

/**
 * Validates Gravity Forms fields with an IBAN mask.
 *
 * @param array $validation_result Contains the validation result and the current Form Object.
 *
 * @return    array                        The new validation result.
 * @since    1.0
 */
function gform_iban_validation( $validation_result ) {
	foreach ( $validation_result['form']['fields'] as &$field ) {

		$fieldValue = rgpost( "input_{$field['id']}" );

		if ( 'iban' == $field['inputMaskValue'] ) {
			if ( 0 == strlen( $fieldValue ) ) { // If empty continue in foreach loop
				continue;
			} else { // If not empty do the IBAN check
				require_once( dirname( __FILE__ ) . '/lib/php-iban.php' );
				if ( ! verify_iban( $fieldValue ) ) {
					$validation_result['is_valid'] = false;
					$field['failed_validation']    = true;
					$field['validation_message']   = __( 'Please enter a valid value.', 'gravityforms' );
				}
			}
		}
	}

	return $validation_result;
}