Something wrong with "Chaing the UI" documentation

HelpLeecher

So I followed the "Changing the UI" tutorial that is in the extensions documentation: http://flarum.org/docs/extend/start/

I replicated the whole thing however I keep getting this error: "Fatal error: Uncaught Error: Call to a member function listen() on null in"

Full error message and contents of my extensions file are here:

What causes this and how can I fix it?

datitisev

The docs are not incorrect in that aspect. You just didn't follow the Event Handlers section.
Your bootstrap.php should actually look like this:

<?php

use Illuminate\Contracts\Events\Dispatcher;
use Flarum\Event\ConfigureClientView;
 
return function (Dispatcher $events) {
    $events->listen(ConfigureClientView::class, function (ConfigureClientView $event) {
        if ($event->isForum()) {
            $event->addAssets(__DIR__.'/js/forum/dist/extension.js');
            $event->addBootstrapper('johnsmith/flarum-ext-myapp/main');
        }
    });
};