search_embedded_form.module

<?php
/**
 * @file
 * Test module implementing a form that can be embedded in search results.
 *
 * Embedded form are important, for example, for e-commerce sites where each
 * search result may included an embedded form with buttons like "Add to cart"
 * for each individual product (node) listed in the search results.
 */

/**
 * Implements hook_menu().
 */
function search_embedded_form_menu() {
  $items['search_embedded_form'] = array(
    'title' => 'Search_Embed_Form',
    'page callback' => 'backdrop_get_form',
    'page arguments' => array('search_embedded_form_form'),
    'access arguments' => array('search content'),
    'type' => MENU_CALLBACK,
  );

  return $items;
}

/**
 * Builds a form for embedding in search results for testing.
 *
 * @see search_embedded_form_form_submit().
 */
function search_embedded_form_form($form, &$form_state) {
  $count = config_get('search.settings', 'search_embedded_form_submitted');

  $form['name'] = array(
    '#type' => 'textfield',
    '#title' => t('Your name'),
    '#maxlength' => 255,
    '#default_value' => '',
    '#required' => TRUE,
    '#description' => t('Times form has been submitted: %count', array('%count' => $count)),
  );

  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Send away'),
  );

  $form['#submit'][] = 'search_embedded_form_form_submit';

  return $form;
}

/**
 * Submit handler for search_embedded_form_form().
 */
function search_embedded_form_form_submit($form, &$form_state) {
  $config = config('search.settings');
  $submit_count = (int) $config->get('search_embedded_form_submitted');
  $config->set('search_embedded_form_submitted', $submit_count + 1)->save();
  backdrop_set_message(t('Test form was submitted'));
}

/**
 * Adds the test form to search results.
 */
function search_embedded_form_preprocess_search_results(&$variables) {
  foreach ($variables['search_results'] as $key => $result)  {
    $form = backdrop_get_form('search_embedded_form_form');
    $snippet = '<p>' . $variables['search_results'][$key]['snippet'] . '</p>';
    $snippet .= backdrop_render($form);
    $variables['search_results'][$key]['snippet'] = $snippet;
  }
}