Moodle event observer not triggered in local plugin - moodle

Question

I have created a plugin at this location moodle/local/redirectafterlogin with the following structure :
redirectafterlogin/
├── db
│   ├── classes
│   │   └── observer.php
│   └── events
│   └── events.php
└── version.php
version.php:
defined('MOODLE_INTERNAL') || die();
$plugin->version = 20170333;
$plugin->requires = 2015111000;
$plugin->component = 'local_redirectafterlogin';
events.php:
defined('MOODLE_INTERNAL') || die();
$observers = array(
array(
'eventname' => 'core\event\user_loggedin',
'callback' => 'local_redirectafterlogin_observer::user_loggedin',
),
array(
'eventname' => 'core\event\user_loggedout',
'callback' => 'local_redirectafterlogin_observer::user_loggedin',
),
);
observer.php:
class local_redirectafterlogin_observer
{
public static function user_loggedin(core\event\base $event)
{
$event_data = $event->get_data();
var_dump($event_data);
die();
}
}
Cached has been cleared a lot of time and version number has been bumped too but the callback is never called!
What's wrong, why does the callback is not triggered?
How can I debug events (is there a way in Moodle to see dispatched events)?

Answer 1

It was a structure mistake! I put the classes folder containing observer.php in the db folder!
After moving the classes folder at the root of the plugin as follow, this is ok, observer is triggered!
Structure that is ok:
redirectafterlogin/
├── classes
│   └── observer.php
├── db
│   └── events.php
└── version.php

Answer 2

I don't think the automatic class loading will be able to find your observer class.
Try adding to the top of the observer class file:
namespace local_redirectafterlogin;
Then change the events.php to:
'callback' => 'local_redirectafterlogin\local_redirectafterlogin_observer'
(You could also greatly shorten the class name, now it is namespaced). Make sure you bump the version number, to reload the events.php file.
You may want to reconsider the naming of your plugin, though, as redirection is not allowed from within an event handler, as that would cause a great many problems.

Answer 3

I made the experience that var_dump or output do stdout gets not trigggert. As quick "debug" i use file_put_contents to a temp logfile