Extended version of AjaxForm that supports formConstruct

AjaxFormPlus.php

<?php
/**
 * @var array    $scriptProperties
 * @var AjaxForm $AjaxForm
 */
$AjaxForm = $modx->getService('ajaxform', 'AjaxForm', $modx->getOption('ajaxform_core_path', null, $modx->getOption('core_path') . 'components/ajaxform/') . 'model/ajaxform/', $scriptProperties);
if (!($AjaxForm instanceof AjaxForm)) {
	return '';
}
$AjaxForm->initialize($modx->context->key);

$snippet = $modx->getOption('snippet', $scriptProperties, 'FormIt', true);
if (!isset($placeholderPrefix)) {
	$placeholderPrefix = 'fi.';
}

if (strtolower($snippet) == 'formconstruct') {
	$scriptProperties['submitVar'] = $modx->getOption('submitVar', $scriptProperties, 'f_submit');
	require_once MODX_CORE_PATH . 'components/form_construct/model/form_construct/formconstruct.class.php';
	$formConstruct = new formConstruct($modx, $scriptProperties);
	$formTpl = $modx->getOption('tpl', $scriptProperties, 'formConstruct_tpl');
	$formId = (int)$modx->getOption('form_id', $scriptProperties, 0);
	if ($formId < 1) {
		return '';
	}
	$form = $modx->getObject('formConstructItem', $formId);
	if (!$form) {
		return '';
	}
	$formFieldsData = $form->get('fields_data');
	$formFieldsData = !empty($formFieldsData) ? json_decode($formFieldsData, true) : array();
	$scriptProperties['emailTo'] = $form->get('email');
	$scriptProperties['validate'] = $formConstruct->getValidateString($formFieldsData);
	$scriptProperties = $formConstruct->getFormItProperties($scriptProperties, $formFieldsData);
	foreach ($modx->placeholders as $key => $val) {
		if (strpos($key, $placeholderPrefix) === 0) {
			unset($modx->placeholders[$key]);
		}
	}
	$content = $formConstruct->makeForm($formConstruct->YAMLLoadString($modx->getChunk($formTpl)), $formFieldsData, $form->get('description'));
	$scriptProperties['snippet'] = 'FormIt';
} else {
	$tpl = $modx->getOption('form', $scriptProperties, 'tpl.AjaxForm.example', true);
	/** @var modChunk $chunk */
	$condition = array(
		'name' => $tpl,
	);
	if (!$chunk = $modx->getObject('modChunk', $condition)) {
		return $modx->lexicon('af_err_chunk_nf', $condition);
	}
	$content = $chunk->getContent();
}

$formSelector = $modx->getOption('formSelector', $scriptProperties, 'ajax_form', true);

// Add selector to tag form
if (preg_match('/form.*?class="(.*?)"/', $content, $matches)) {
	$classes = explode(' ', $matches[1]);
	if (!in_array($formSelector, $classes)) {
		$classes[] = $formSelector;
		$classes = str_replace('class="' . $matches[1] . '"', 'class="' . implode(' ', $classes) . '"', $matches[0]);
		$content = str_replace($matches[0], $classes, $content);
	}
} else {
	$content = str_replace('<form', '<form class="' . $formSelector . '"', $content);
}

// Add method = post
if (preg_match('/form.*?method="(.*?)"/', $content)) {
	$content = preg_replace('/form(.*?)method="(.*?)"/', 'form\\1method="post"', $content);
} else {
	$content = str_replace('<form', '<form method="post"', $content);
}

// Add action for form processing
$hash = md5(http_build_query($scriptProperties));
$action = '<input type="hidden" name="af_action" value="' . $hash . '" />';
if ((strpos($content, '</form>') !== false)) {
	if (preg_match('/<input.*?name="af_action".*?>/', $content, $matches)) {
		$content = str_replace($matches[0], '', $content);
	}
	$content = str_replace('</form>', "\n\t$action\n</form>", $content);
}

// Save settings to user`s session
$_SESSION['AjaxForm'][$hash] = $scriptProperties;

// Call snippet for preparation of form
$action = !empty($_REQUEST['af_action']) ? $_REQUEST['af_action'] : $hash;

$AjaxForm->process($action, $_REQUEST);

// Return chunk
return $content;