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<?php
/**
 * Gravity Wiz // Gravity Forms // Double Confirmation Fields
 *
 * Require a field's value to be entered twice to confirm it.
 *
 * @version 0.2
 * @author  David Smith <david@gravitywiz.com>
 * @license GPL-2.0+
 * @link    http://gravitywiz.com/custom-field-confirmation/
 *
 * Plugin Name: Snippet Name
 * Plugin URI: http://gravitywiz.com/custom-field-confirmation/
 * Description: Require a field's value to be entered twice to confirm it.
 * Author: Gravity Wiz
 * Version: 0.2
 * Author URI: http://gravitywiz.com
 */
add_filter('gform_validation', 'gfcf_validation');
function gfcf_validation($validation_result) {
	global $gfcf_fields;

	$form = $validation_result['form'];
	$confirm_error = false;

	if(!isset($gfcf_fields[$form['id']]))
		return $validation_result;

	foreach($gfcf_fields[$form['id']] as $confirm_fields) {

		$values = array();

		// loop through form fields and gather all field values for current set of confirm fields
		foreach($form['fields'] as $field) {
			if(!in_array($field['id'], $confirm_fields))
				continue;

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

		}

		// filter out unique values, if greater than 1, a value was different
		if(count(array_unique($values)) <= 1)
			continue;

		$confirm_error = true;

		foreach($form['fields'] as &$field) {
			if(!in_array($field['id'], $confirm_fields))
				continue;

			// fix to remove phone format instruction
			if(RGFormsModel::get_input_type($field) == 'phone')
				$field['phoneFormat'] = '';

			$field['failed_validation'] = true;
			$field['validation_message'] = 'Your values do not match.';
		}

	}

	$validation_result['form'] = $form;
	$validation_result['is_valid'] = !$validation_result['is_valid'] ? false : !$confirm_error;

	return $validation_result;
}

function register_confirmation_fields($form_id, $fields) {
	global $gfcf_fields;

	if(!$gfcf_fields)
		$gfcf_fields = array();

	if(!isset($gfcf_fields[$form_id]))
		$gfcf_fields[$form_id] = array();

	$gfcf_fields[$form_id][] = $fields;
}

register_confirmation_fields( 1, array( 2, 3 ) );