Creating a JSON callback page in a Drupal module

Drupal

This can useful for AJAX scripts or REST applications that need JSON output. In your my_module.module, extend your hook_menu():

/**
 * Implements hook_menu().
 */
function my_module_menu() {
  $items = array();

  // ...

  // issue #1210: provide a passthrough for blog post comments
  $items['my/callback] = array(
    'title' => 'My callback',
    'description' => 'My callback description',
    'access arguments' => TRUE,
    'access callback' => TRUE,
    'page callback' => 'my_module_json_callback',
    'file' => 'my_module.inc',
  );

  return $items;
}

And then in my_module.inc, use drupal_json_output:

/**
 * Page callback.
 */
function my_module_json_callback() {
  $json = array(
    'hello' => 'world',
    'meow' => array(1,2,3),
  );

  drupal_json_output($json);
}

You can then access your callback (after clearing your caches) by calling http://localhost/drupal/my/callback.