<?php
// $Id: rules_forms.module,v 1.1.2.4 2009/08/19 11:20:17 fago Exp $


/**
 * @file
 * Rules forms module.
 */

// Defines paths of the admin interface
define('RULES_ADMIN_FORMS_PATH', RULES_ADMIN_PATH .'/forms');


/**
 * Implementation of hook_help().
 */
function rules_forms_help($path, $arg) {
  if ($path === RULES_ADMIN_FORMS_PATH) {
    return '<p>'. t('Settings and overview of form events.') .'</p>';
  }
}

/**
 * Implementation of hook_menu().
 */
function rules_forms_menu() {
  $items = array();
  $items[RULES_ADMIN_FORMS_PATH] = array(
    'title' => 'Form events',
    'description' => 'Configure Rules forms events.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('rules_forms_admin_events'),
    'access arguments' => array('administer rules'),
    'type' => MENU_NORMAL_ITEM,
    'weight' => 6,
    'file' => 'rules_forms.admin.inc',
  );
  $items[RULES_ADMIN_FORMS_PATH .'/%/activate'] = array(
    'title' => 'Activate events for a form',
    'type' => MENU_CALLBACK,
    'page callback' => 'rules_forms_activate',
    'page arguments' => array(3),
    'access arguments' => array('administer rules'),
    'file' => 'rules_forms.admin.inc',
  );
  return $items;
}

/**
 * Implementation of hook_form_alter().
 */
function rules_forms_form_alter(&$form, &$form_state, $form_id) {
  $form_events = variable_get('rules_forms_events', array());
  // Invoke event if form is enabled
  if (isset($form_events[$form_id])) {
    rules_forms_invoke_event('form_built', $form, $form_state, $form_id);
    $form['#after_build'][] = 'rules_forms_after_build';
    if (!empty($_SESSION['rules_forms_element_ids'])) {
      rules_forms_add_element_id($form);
    }
  }
  // Display form ID message if enabled for this session.
  if (!empty($_SESSION['rules_forms_message'])) {
    $link = l($form_id, RULES_ADMIN_FORMS_PATH .'/'. $form_id .'/activate/');
    $msg = t('Activate events for ');
    drupal_set_message($msg . $link, 'status', FALSE);
  }
}

/**
 * Submit handler to invoke "form submitted" events
 */
function rules_forms_event_submit(&$form, &$form_state) {
  rules_forms_invoke_event('form_submit', $form, $form_state);
}

/**
 * Validation handler to invoke "form validate" events
 */
function rules_forms_event_validate(&$form, &$form_state) {
  rules_forms_invoke_event('form_validate', $form, $form_state);
}

/**
 * Invoke rules event of a certain type.
 */
function rules_forms_invoke_event($event_type, &$form, &$form_state, $form_id = NULL) {
  if (empty($form_id)) {
    $form_id = $form['form_id']['#value'];
  }
  $action_args = array(
    'form' => &$form,
    'form_state' => &$form_state,
    'form_id' => $form_id,
  );
  rules_invoke_event($form_id .'_'. $event_type, $action_args);
}

/**
 * Add element IDs as prefix/suffix code to all form elements.
 */
function rules_forms_add_element_id(&$form, $parent = '') {
  $bracket = ($parent === '') ? '' : ']';
  foreach (element_children($form) as $key) {
    if (isset($form[$key]['#type'])) {
      if ($form[$key]['#type'] === 'hidden' || $form[$key]['#type'] === 'token') {
        $element_id = '<div class="rules_forms_element_id">'. t('Hidden element ID: %elem', array('%elem' => $parent . $key . $bracket)) .'</div>';
      }
      else {
        $element_id = '<div class="rules_forms_element_id">'. t('Element ID: %elem', array('%elem' => $parent . $key . $bracket)) .'</div>';
      }
      $form[$key]['#suffix'] = isset($form[$key]['#suffix']) ? $form[$key]['#suffix'] . $element_id : $element_id;
    }
    else {
      $element_id = '<div class="rules_forms_element_id">'. t('Container element ID: %elem', array('%elem' => $parent . $key . $bracket)) .'</div>';
      $form[$key]['#prefix'] = isset($form[$key]['#suffix']) ? $form[$key]['#suffix'] . $element_id : $element_id;
    }
    // recursive call on children
    rules_forms_add_element_id($form[$key], $parent . $key . $bracket .'[');
  }
}

/**
 * Add submit and validation callbacks to form, buttons, etc. to invoke
 * corresponding events.
 */
function rules_forms_after_build($form, &$form_state) {
  drupal_add_css(drupal_get_path('module', 'rules_forms') .'/rules_forms.css');
  if (!$form_state['submitted']) {
    return $form;
  }
  if (empty($form_state['submit_handlers'])) {
    $form['#submit'][] = 'rules_forms_event_submit';
  }
  else {
    $form_state['submit_handlers'][] = 'rules_forms_event_submit';
  }
  if (empty($form_state['validate_handlers'])) {
    $form['#validate'][] = 'rules_forms_event_validate';
  }
  else {
    $form_state['validate_handlers'][] = 'rules_forms_event_validate';
  }
  return $form;
}

/**
 * Implementation of hook_rules_import().
 * We need to activate the form event of the imported rule.
 */
function rules_forms_rules_import(&$rule) {
  $event = $rule['#set'];
  // Check if it is a form-event-triggered rule
  if (preg_match('/^event_(.)+_form_(built|submit|validate)$/', $event)) {
    // Remove prefix/suffixes to get the form ID
    $exploded = explode('_', $event);
    $length = count($exploded);
    unset($exploded[0], $exploded[$length-1], $exploded[$length-2]);
    $form_id = implode('_', $exploded);
    $form_events = variable_get('rules_forms_events', array());
    // Activate event if it hasn't been activated yet.
    if (!isset($form_events[$form_id])) {
      $form_events[$form_id] = drupal_ucfirst(str_replace('_', ' ', $form_id));
      variable_set('rules_forms_events', $form_events);
    }
  }
}