ModuleHandler::buildImplementationInfo

protected ModuleHandler::buildImplementationInfo($hook)

protected function buildImplementationInfo($hook) {
  $implementations = array();
  $hook_info = $this->getHookInfo();
  foreach ($this->moduleList as $module => $extension) {
    $include_file = isset($hook_info[$hook]['group']) && $this->loadInclude($module, 'inc', $module . '.' . $hook_info[$hook]['group']);
    // Since $this->implementsHook() may needlessly try to load the include
    // file again, function_exists() is used directly here.
    if (function_exists($module . '_' . $hook)) {
      $implementations[$module] = $include_file ? $hook_info[$hook]['group'] : FALSE;
    }
  }
  // Allow modules to change the weight of specific implementations, but avoid
  // an infinite loop.
  if ($hook != 'module_implements_alter') {
    // Remember the original implementations, before they are modified with
    // hook_module_implements_alter().
    $implementations_before = $implementations;
    // Verify implementations that were added or modified.
    $this->alter('module_implements', $implementations, $hook);
    // Verify new or modified implementations.
    foreach (array_diff_assoc($implementations, $implementations_before) as $module => $group) {
      // If an implementation of hook_module_implements_alter() changed or
      // added a group, the respective file needs to be included.
      if ($group) {
        $this->loadInclude($module, 'inc', "$module.$group");
      }
      // If a new implementation was added, verify that the function exists.
      if (!function_exists($module . '_' . $hook)) {
        throw new \RuntimeException("An invalid implementation {$module}_{$hook} was added by hook_module_implements_alter()");
      }
    }
  }
  return $implementations;
}