How to split the code of a module into separated files

Question

I am very curious to know how a Drupal module can be dis-integrated into multiple include files. A number of hook support to link include components, like hook_menu, hook_theme etc.

Once I planned to simplify one of my complex module that have reached to 2.3K of lines with half of its feature set. I have to roll back all those steps due to lack of knowledge about the scope of inclusion.

Help me in this regard if there is some detailed information.

Daric

Answer 1

What Nikit said is correct.
I will add there are some hooks that are allowed to define which files need to be loaded. Examples of such hooks are hook_theme(), and hook_menu().

A module should never unconditionally load a file it needs calling module_load_include() from outside a function.

function book_menu() {
  $items['admin/content/book'] = array(
    'title' => 'Books',
    'description' => "Manage your site's book outlines.",
    'page callback' => 'book_admin_overview',
    'access arguments' => array('administer book outlines'),
    'file' => 'book.admin.inc',
  );
  $items['admin/content/book/list'] = array(
    'title' => 'List',
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  $items['admin/content/book/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('book_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'type' => MENU_LOCAL_TASK,
    'weight' => 8,
    'file' => 'book.admin.inc',
  );
  // …
}

function user_theme() {
  return array(
    'user_picture' => array(
      'arguments' => array('account' => NULL),
      'template' => 'user-picture',
    ),
    'user_profile' => array(
      'arguments' => array('account' => NULL),
      'template' => 'user-profile',
      'file' => 'user.pages.inc',
    ),
    // …
    'user_admin_perm' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    // …
  );
}

Kinsey

But my main intention is about several data access functions those are used in various parts. e.g. comments. comment_total_count(), comment_today_count() is used in templates, comment_thread() is required on admin page as well as on content page. comment_insert() on content page while comment_remove() and comment_edit() on admin page. Do I need to use conventional require or include syntax? And what about to include multiple files? – Daric

The function used to include PHP files is module_load_include(). You can include one, or more files. – Kinsey

Answer 2

Using more files, is just a matter of grouping similar things together in the same file, to keep it more managed. Typical files used is

• .admin.inc for all administration stuff, menu callbacks, forms etc.
• .pages.inc for frontend menu callbacks.
• .theme.inc for theme functions, preprocess hooks etc.
• .forms.inc for non admin forms and their handlers.

This is more a coding style that anything else. So this is just to help yourself maintain the code you have written.

Pirri

It's for performance as well. All the functions from .module files get loaded at every initialisation. – Endemic

Answer 3

It's simple, just review other big modules (like cck, views, etc). Main hooks should be in module, others should be in different files - themers, admin pages, other pages, service functions and so on...

Doone