Model Events

Models allow you to implement events that will be thrown while performing an insert/update/delete which can be used to define business rules. The following are the events supported by Phalcon\Mvc\Model and their order of execution:

The easier way to make a model react to events is to implement a method with the same name of the event in the model’s class:

Events can be used to assign values before performing an operation, for example:

<?php
use Phalcon\Mvc\Model;
class Products extends Model
{
    public function beforeCreate()
    {
        // Set the creation date
        $this->created_at = date('Y-m-d H:i:s');
    }
    public function beforeUpdate()
    {
        // Set the modification date
        $this->modified_in = date('Y-m-d H:i:s');
    }
}

Using a custom Events Manager

Additionally, this component is integrated with Phalcon\Events\Manager, this means we can create listeners that run when an event is triggered.

<?php
namespace Store\Toys;
use Phalcon\Mvc\Model;
use Phalcon\Events\Event;
use Phalcon\Events\Manager as EventsManager;
class Robots extends Model
{
    public function initialize()
    {
        $eventsManager = new EventsManager();
        // Attach an anonymous function as a listener for 'model' events
        $eventsManager->attach(
            'model:beforeSave',
            function (Event $event, $robot) {
                if ($robot->name === 'Scooby Doo') {
                    echo "Scooby Doo isn't a robot!";
                    return false;
                }
                return true;
            }
        );
        // Attach the events manager to the event
        $this->setEventsManager($eventsManager);
    }
}

If we want all objects created in our application use the same EventsManager, then we need to assign it to the Models Manager:

<?php
use Phalcon\Events\Event;
use Phalcon\Events\Manager as EventsManager;
// Registering the modelsManager service
$di->setShared(
    'modelsManager',
    function () {
        // Attach an anonymous function as a listener for 'model' events
        $eventsManager->attach(
            'model:beforeSave',
            function (Event $event, $model) {
                if (get_class($model) === \Store\Toys\Robots::class) {
                    if ($model->name === 'Scooby Doo') {
                        echo "Scooby Doo isn't a robot!";
                        return false;
                    }
                }
                return true;
            }
        );
        // Setting a default EventsManager
        $modelsManager = new ModelsManager();
        $modelsManager->setEventsManager($eventsManager);
        return $modelsManager;
    }
);

If a listener returns false that will stop the operation that is executing currently.

When using high-level abstraction components such as to access a database, it is difficult to understand which statements are finally sent to the database system. Phalcon\Mvc\Model is supported internally by . Phalcon\Logger interacts with , providing logging capabilities on the database abstraction layer, thus allowing us to log SQL statements as they happen.

<?php
use Phalcon\Logger;
use Phalcon\Events\Manager;
use Phalcon\Logger\Adapter\File as FileLogger;
use Phalcon\Db\Adapter\Pdo\Mysql as Connection;
$di->set(
    'db',
    function () {
        $eventsManager = new EventsManager();
        $logger = new FileLogger('app/logs/debug.log');
        // Listen all the database events
        $eventsManager->attach(
            'db:beforeQuery',
            function ($event, $connection) use ($logger) {
                $logger->log(
                    $connection->getSQLStatement(),
                    Logger::INFO
                );
            }
        );
        $connection = new Connection(
            [
                'host'     => 'localhost',
                'username' => 'root',
                'password' => 'secret',
                'dbname'   => 'invo',
            ]
        );
        // Assign the eventsManager to the db adapter instance
        $connection->setEventsManager($eventsManager);
        return $connection;
    }
);

As models access the default database connection, all SQL statements that are sent to the database system will be logged in the file:

Thanks to Phalcon\Db, the underlying component of , it’s possible to profile the SQL statements generated by the ORM in order to analyze the performance of database operations. With this you can diagnose performance problems and to discover bottlenecks.

<?php
use Phalcon\Db\Profiler as ProfilerDb;
use Phalcon\Events\Manager as EventsManager;
use Phalcon\Db\Adapter\Pdo\Mysql as MysqlPdo;
    'profiler',
    function () {
        return new ProfilerDb();
    true
);
$di->set(
    'db',
    function () use ($di) {
        $eventsManager = new EventsManager();
        // Get a shared instance of the DbProfiler
        $profiler = $di->getProfiler();
        // Listen all the database events
        $eventsManager->attach(
            'db',
            function ($event, $connection) use ($profiler) {
                if ($event->getType() === 'beforeQuery') {
                    $profiler->startProfile(
                        $connection->getSQLStatement()
                    );
                }
                if ($event->getType() === 'afterQuery') {
                    $profiler->stopProfile();
                }
            }
        );
        $connection = new MysqlPdo(
            [
                'host'     => 'localhost',
                'username' => 'root',
                'password' => 'secret',
                'dbname'   => 'invo',
            ]
        );
        // Assign the eventsManager to the db adapter instance
        $connection->setEventsManager($eventsManager);
        return $connection;
    }
);

Profiling some queries:

<?php
use Store\Toys\Robots;
// Send some SQL statements to the database
Robots::find();
Robots::find(
    [
        'order' => 'name',
    ]
);
Robots::find(
    [
        'limit' => 30,
    ]
);
// Get the generated profiles from the profiler
$profiles = $di->get('profiler')->getProfiles();
foreach ($profiles as $profile) {
   echo 'SQL Statement: ', $profile->getSQLStatement(), '\n';
   echo 'Start Time: ', $profile->getInitialTime(), '\n';
   echo 'Final Time: ', $profile->getFinalTime(), '\n';
   echo 'Total Elapsed Time: ', $profile->getTotalElapsedSeconds(), '\n';
}

Each generated profile contains the duration in milliseconds that each instruction takes to complete as well as the generated SQL statement.