Hooks: Actions and Filters
Modifying WordPress Without Editing Core
Hooks are the mechanism that let developers change WordPress's behaviour and output without touching any core files, keeping customisations update-safe.
Actions
Actions let you run custom code at a specific point in WordPress's execution, such as after a post is published or when the site footer loads.
You attach a function to an action using add_action(), specifying the hook name and your custom function.
Filters
Filters let you modify a piece of data before it's used or displayed, such as changing post content or excerpt length.
You attach a function to a filter using add_filter(), and your function must return the modified value.
| Hook Type | What It Does | Function Used |
|---|---|---|
| Action | Runs code at a specific point | add_action() |
| Filter | Modifies data before it's used | add_filter() |
Hooks power a lot of custom functionality, including how WordPress exposes data externally through the REST API and shortcodes.
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