It does two different tasks:
- If you don’t pass in your callback name, then it checks if any callbacks are registered to the specified event.
- Else, it checks if the callback (your function, method, or closure) is registered to a specific filter hook event.
- The name of the event (filter hook) you want to check.
- The fully qualified name of your callback.
- If you pass in a callback, then it returns the priority number for your callback if it is registered; else you’ll get a
- Otherwise, it turns
TRUEif there are callbacks are registered; else
Your functions are bloated. Put them on a diet. Think "skinny" and "as few lines as possible."
More coming soon…keep checking back.
These are the PHP constructs used in WordPress Core for