I want to add a plugin system to my PHP application.
I'd like to create a hook system where my plugins register themselves to these hooks. So for so good. The problem is knowing from start what kind of hooks to create.
Are there any guidelines on how to do this? Should I have a hook for every point in the app where I might want to update data? Hooks for outputing data?
Would I need to have a hook for something like "before_script_ends", "before_avatar_output"?
This seems pretty opinion based...
I'd start with requirements of what your developers are asking for in this plugin system. Try just kicking it off thinking about minimum viable product. What things would be most beneficial. I'd vote with routing type features so probably create hooks for that. That may actually be all you need.
Also decide if a plugin system is what you want. You might prefer more separated apps. In which case a rest based/oauth like approach might be more appropriate.
It is hard to say with out some specific use case.