Explaining how custom handlers work

MrCaspan

So i was reading this documentation here https://docs.vanillaforums.com/developer/addons/events-and-handlers/ and I understand how a handler works.. I can have my plugin code alter/add/remove/read date based on the fireEvent trigger..

I was looking at the following code form another plugin and saw this function that is attaching to what? It does not end with Handler. I assume this is acting on the /applications/vanilla/controllers/class.categoriescontroller.php but where inside that file would this codes insertion point be?

public function categoriesController_render_before($sender) {
    // Do some stuff
}

MrCaspan

Magic events were an elaborate system of hook possibilities that involved the method prefix ‘x’ and PHP’s __call() method. Currently, there is only one undeprecated magic event in Vanilla: render_before. It invokes just before the page is rendered. Example use: base_render_before($sender). It is best to avoid when another event is usable.

So does this mean that in the entire "/applications/vanilla/controllers/class.categoriescontroller.php" if there is a call to "$this->render()" this function will fire?

R_J

Correct. Simply add echo '<!-- my test -->'; or echo '<!-- ' . $sender->RequestMethod . ' -->'; there and look at the resulting html to validate your assumption. And even worse than using someController_render_before is base_render_before, because that is called at the beginning of every controller render call. Just take a look at the source code to understand why you should avoid abusing that magic method... https://github.com/vanilla/vanilla/blob/release/3.3/applications/vanilla/settings/class.hooks.php#L656-L667 😉