Wordpress Simple Actions & Filters

Curse the gods, this simple functionality can seem complicated. I think its a combination of the terminology and word choice being so unhelpful. Do I add , apply or do a filter or action? What is a hook here? Or maybe I need to register it? It's all very vague, and I constantly forget.

Anyway, here's some pretty pictures instead. I've made it as basic as possible, more for remembering which one to use and where.

🧗🏻‍♀️ Basic Actions (does a task, returns nothing)

Plug in new code at a specific point.

1. Once you've registered your action with a my_action_name in functions.php or a plugin, you can now call it.
2. Whenever the code gets to a do_action('my_action_name'), it'll run the associated callback function run_this_function.
3. No need to return anything.

🔗 Action Links:

https://developer.wordpress.org/reference/functions/do_action/

https://developer.wordpress.org/reference/functions/add_action/

🔍 Basic Filters (returns filtered data)

Pass in a value, change the value, pass new value back.

1. Registered your filter with an add_filter referencing a callback function.
2. Run the filter with the apply_filter function.
3. The callback function will take the passed value, change it and return it back. (filtering it)
4. MUST return something (the new value).

🔗 Filter Links:

https://developer.wordpress.org/reference/functions/apply_filters/

https://developer.wordpress.org/reference/functions/add_filter/