{"id":835039,"date":"2026-02-26T13:54:29","date_gmt":"2026-02-26T13:54:29","guid":{"rendered":"https:\/\/www.knowband.com\/blog\/?p=835039\/"},"modified":"2026-03-10T13:15:19","modified_gmt":"2026-03-10T13:15:19","slug":"how-to-use-prestashops-override-system-without-breaking-core","status":"publish","type":"post","link":"https:\/\/www.knowband.com\/blog\/prestashop-blog\/how-to-use-prestashops-override-system-without-breaking-core\/","title":{"rendered":"How to Use PrestaShop’s Override System Without Breaking Core"},"content":{"rendered":"

PrestaShop\u2019s override system allows you customize core behavior without touching original files. But used carelessly, it creates fragile stores that break on updates. This guide by Knowband covers how overrides work, when to use them, and three critical gotchas every developer should know.<\/span><\/p>\n

What Is the Override System?<\/b><\/h2>\n

PrestaShop uses PHP inheritance to let you swap in your own version of any core class without touching the originals. Every core class is named with a Core suffix for example, ProductCore. If you create \/override\/classes\/Product.php with a class called Product that extends ProductCore, PrestaShop loads your version instead. The same applies to controllers.<\/span><\/p>\n

Only override the specific methods you need to change never copy an entire class file. This keeps your override lean and far less likely to conflict with future updates.<\/span><\/p>\n

Example, exposing the current controller name to your header template:<\/span><\/p>\n

Where to Put Your Override Files<\/b><\/h2>\n

Overrides can live in two places. The global \/override\/ directory at the root of your installation is active immediately after clearing the cache. The better approach is bundling overrides inside a module.<\/span><\/p>\n

Placing an override inside a module (e.g. \/modules\/mymodule\/override\/classes\/Product.php) causes PrestaShop to copy it to \/override\/ on installation and remove it cleanly on uninstall. This is the recommended approach.<\/span><\/p>\n

A quick example of a class override. Say you want to expose the current controller name to your header template:<\/span><\/p>\n

\/\/ \/override\/classes\/controllers\/FrontController.php<\/span>\r\n\r\nclass FrontController extends FrontControllerCore {<\/span>\r\n\r\n\u00a0\u00a0\u00a0\u00a0public function initHeader() {<\/span>\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0self::$smarty->assign('currentController', get_class($this));<\/span>\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return parent::initHeader();<\/span>\r\n\r\n\u00a0\u00a0\u00a0\u00a0} }<\/span>\r\n\r\nAlways call the parent method unless you have a deliberate reason not to. Skipping it will silently break core functionality.<\/span><\/pre>\n
Overriding Module Classes and Controllers<\/b><\/h2>\n
Since PrestaShop 1.6, you can override module classes too. Append \u201cOverride\u201d to the class name (e.g. BlockUserInfoOverride extending BlockUserInfo) and place it under \/override\/modules\/. The same pattern applies to module controllers. After any override, clear the cache, specifically delete \/cache\/class_index.php, or it won\u2019t take effect.<\/span><\/p>\n
When NOT to Use Overrides<\/b><\/h2>\n
Overrides are exclusive \u2014 only one per class can exist. They\u2019re also forbidden in marketplace modules and should be reserved for private store customisations. Before reaching for an override, consider one of these alternatives:<\/span><\/p>\n