How to log in Moodle 3.10?

Question

I wrote my own authentication plugin for Moodle 3.10. I would just like to add a log whenever the login fails. Something like this:

$log->info('User with username XYZ could not login.');

How to do this in Moodle?

I checked the developer docs in Moodle at https://docs.moodle.org/310/en/Logs but it just states where to find the logs. Not how to add logs

According to Moodle 4 docs I tried to create a custom event in my plugin auth/myapi :

Event in /auth/myapi/user_loggedin.php :

<?php

namespace myapi\event;
defined('MOODLE_INTERNAL') || die();

class user_loggedin extends \core\event\base {
    protected function init() {
        $this->data['crud'] = 'r';
        $this->data['edulevel'] = self::LEVEL_OTHER;
    }

    public static function get_name() {
        return get_string('event_userloggedin', 'myapi');
    }

    public function get_description() {
        $username = $this->other['username'];
        $email = $this->other['email'];
        $firstname = $this->other['firstname'];
        $lastname = $this->other['lastname'];

        return "The user '{$username}' with email '{$email}' named '{$firstname} {$lastname}' logged in.";
    }


    public function get_custom_data() {
        // Add custom data accessors here, if needed.
    }
}

And inside my core file in /auth/myapi/auth.php:

<?php
/**
 * External API authentication plugin
 *
 * Validates username and password against an external API, creates a new user if necessary,
 * and adds the user to a specific cohort based on the profile returned by the API.
 *
 * @package    auth_externalapi
 */

defined('MOODLE_INTERNAL') || die();

require_once(__DIR__ . '/user_loggedin.php');


// somewhere in my code:
$event = \myapi\event\user_loggedin::create([
            'context' => \context_system::instance(),
            'other' => [
                'username' => $user->username,
                'email' => $user->email,
                'firstname' => $user->firstname,
                'lastname' => $user->lastname,
            ],
        ]);
$event->trigger();

But in the moodle reports logs I just find

Unknown event (\myapi\event\user_loggedin)

Answer 1

The Events API creates an entry in the log

There is an existing event for a login failure

$eventdata = ['other' =>
                ['username' => 'unknown',
                'reason' => AUTH_LOGIN_XXX]
             ];
$event = \core\event\user_login_failed::create($eventdata);
$event->trigger();

Replace AUTH_LOGIN_XXX with one of these constants

/** Can not login because user does not exist. */
define('AUTH_LOGIN_NOUSER', 1);

/** Can not login because user is suspended. */
define('AUTH_LOGIN_SUSPENDED', 2);

/** Can not login, most probably password did not match. */
define('AUTH_LOGIN_FAILED', 3);

/** Can not login because user is locked out. */
define('AUTH_LOGIN_LOCKOUT', 4);

/** Can not login becauser user is not authorised. */
define('AUTH_LOGIN_UNAUTHORISED', 5);

Or you can create your own event, they are pretty simply to set up

https://docs.moodle.org/dev/Events_API

Basically, an event class is stored in /yourpluginname/classes/event/event_name.php

Search the existing Moodle code for extends \core\event\base for examples