An extension can replace a kernel module #

This page is for developers who need to change how a whole module works. A module is a set of views behind a URL (content/view, user/login, shop/basket). Until January 2024 the kernel's module won whenever an extension offered a module of the same name, so an extension could add modules but not replace one. Now the module repositories are searched so that extensions come first: put a module with the same name in your extension, and it is used instead of the kernel's.

When to use it #

Replace a whole module when a view needs more than a template override or an event can give, for example a login flow with an extra step, or a changed basket. For small changes prefer the RAD extension points and view classes (commands, cronjob parts and module views as classes).

Do it #

1. Create the module in your extension, with the same layout as a kernel module:

   extension/myext/modules/user/module.php
   extension/myext/modules/user/login.php

2. Make sure the extension is active (settings/override/site.ini.append.php, [ExtensionSettings] ActiveExtensions[]=myext) and lists itself as a module repository. An extension does this in its own settings/module.ini.append.php:

   [ModuleSettings]
   ExtensionRepositories[]=myext

3. Clear the caches:

   php bin/php/ezcache.php --clear-all --allow-root-user

4. Open the URL (for example /user/login). The extension's view runs.

Limit: a view you do not define in your copy of the module is not inherited. The whole module is replaced, so copy every view you still need.

Settings #

How it works #

eZModule::activeModuleRepositories() (lib/ezutils/classes/ezmodule.php) builds the list of module directories from ModuleRepositories[] and then from ExtensionRepositories[]. Since 24 January 2024 (c6b90d723d) it reverses the combined list, so the extension repositories are searched first. The first directory that holds a module with the requested name wins.

A related robustness fix #

A view script of an incomplete extension (the ownerchange extension was one) can return something that is not the expected array. Since October 2024 (884f21e963) eZModule sets the navigation keys (is_default_navigation_part, navigation_part) on the result only when it is an array (at HEAD the check reads !is_string). A view returning a different type no longer ends in a fatal error while the page is assembled.

Related pages #

• Extensions in more than one folder
• Extension loading order
• Behaviour changes of the legacy extensions
• Changelogs: 6.0.1 (module order), 6.0.5 (robustness fix)
• History: January 2024, second half, September 2024, October 2024