db-models-events.md

layout	language	version	title	keywords
default	en	4.0	Model Events	models, events, events manager

Model Events

---

 

Overview

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:

Operation	Name	Stop?	Explanation
Insert	afterCreate	No	Runs after creating a record
Insert/Update	afterSave	No	Runs after saving a record
Update	afterUpdate	No	Runs after updating a record
Insert/Update	afterValidation	Yes	Is executed after the fields are validated for not null/empty strings or foreign keys
Insert	afterValidationOnCreate	Yes	Is executed after the fields are validated for not null/empty strings or foreign keys on an insert
Update	afterValidationOnUpdate	Yes	Is executed after the fields are validated for not null/empty strings or foreign keys on an update
Insert	beforeCreate	Yes	Runs before creating a record
Insert/Update	beforeSave	Yes	Runs before saving a record
Update	beforeUpdate	Yes	Runs before updating a record
Insert/Update	beforeValidation	Yes	Is executed before the fields are validated for not null/empty strings or foreign keys
Insert	beforeValidationOnCreate	Yes	Is executed before the fields are validated for not null/empty strings or foreign keys on an insert
Update	beforeValidationOnUpdate	Yes	Is executed before the fields are validated for not null/empty strings or foreign keys on an update
Insert/Update	onValidationFails	Yes	Is executed after an integrity validator fails
Insert/Update	prepareSave	No	Is executed before saving and allows data manipulation
Insert/Update	validation	Yes	Is executed before the fields are validated for not nulls/empty strings or foreign keys on an update

Events

Models act as listeners to the events manager. Therefore we only need to implement the events above in the models directly as public methods:

<?php

namespace MyApp\Models;

use Phalcon\Mvc\Model;

/**
 * Class Invoices
 *
 * @property string $inv_created_at
 * @property int    $inv_cst_id
 * @property int    $inv_id
 * @property string $inv_number
 * @property string $inv_title
 * @property float  $inv_total
 */
class Invoices extends Model
{
    /**
     * @var int
     */
    public $inv_cst_id;

    /**
     * @var string
     */
    public $inv_created_at;

    /**
     * @var int
     */
    public $inv_id;

    /**
     * @var string
     */
    public $inv_number;

    /**
     * @var string
     */
    public $inv_title;

    /**
     * @var float
     */
    public $inv_total;

    public function beforeValidationOnCreate()
    {
        if ($this->inv_total < 1) {
            $this->inv_total = 0;
        }
    }
}

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

<?php

namespace MyApp\Models;

use Phalcon\Mvc\Model;
use function str_pad;

/**
 * Class Invoices
 *
 * @property string $inv_created_at
 * @property int    $inv_cst_id
 * @property int    $inv_id
 * @property string $inv_number
 * @property string $inv_title
 * @property float  $inv_total
 */
class Invoices extends Model
{
    /**
     * @var int
     */
    public $inv_cst_id;

    /**
     * @var string
     */
    public $inv_created_at;

    /**
     * @var int
     */
    public $inv_id;

    /**
     * @var string
     */
    public $inv_number;

    /**
     * @var string
     */
    public $inv_title;

    /**
     * @var float
     */
    public $inv_total;

    public function beforeCreate()
    {
        $date     = date('YmdHis');
        $customer = substr(
            str_pad(
                $this->inv_cst_id, 6, '0', STR_PAD_LEFT
            ),
            -6
        );

        $this->inv_number = 'INV-' . $customer . '-' . $date;
    }
}

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 MyApp\Models;

use Phalcon\Mvc\Model;
use Phalcon\Events\Manager;

/**
 * Class Invoices
 *
 * @property string $inv_created_at
 * @property int    $inv_cst_id
 * @property int    $inv_id
 * @property string $inv_number
 * @property string $inv_title
 * @property float  $inv_total
 */
class Invoices extends Model
{
    /**
     * @var int
     */
    public $inv_cst_id;

    /**
     * @var string
     */
    public $inv_created_at;

    /**
     * @var int
     */
    public $inv_id;

    /**
     * @var string
     */
    public $inv_number;

    /**
     * @var string
     */
    public $inv_title;

    /**
     * @var float
     */
    public $inv_total;

    public function initialize()
    {
        $eventsManager = new Manager();

        $eventsManager->attach(
            'model:beforeSave',
            function (Event $event, $invoice) {
                if ($invoice->inv_total < 1) {
                    return false;
                }

                return true;
            }
        );

        $this->setEventsManager($eventsManager);
    }
}

In the example given above, the Events Manager only acts as a bridge between an object and a listener (the anonymous function). Events will be fired to the listener when Invoices are saved:

<?php

use MyApp\Models\Invoices;

$invoice = new Invoices();
$invoice->inv_cst_id = 10;
$invoice->inv_title = 'Invoice for ACME Inc.';

$invoice->save();

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

<?php

use MyApp\Models\Invoices;
use Phalcon\Di\FactoryDefault;
use Phalcon\Events\Event;
use Phalcon\Events\Manager;
use Phalcon\Mvc\Model\Manager as ModelsManager;

$container = new FactoryDefault();
$container->setShared(
    'modelsManager',
    function () {
        $eventsManager = new Manager();

        $eventsManager->attach(
            'model:beforeSave',
            function (Event $event, $model) {
                if (get_class($model) === Invoices::class) {
                    if ($model->inv_total < 1) {
                        return false;
                    }
                }

                return true;
            }
        );

        $modelsManager = new ModelsManager();
        $modelsManager->setEventsManager($eventsManager);

        return $modelsManager;
    }
);

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

Logging SQL Statements

When using high-level abstraction components such as Phalcon\Mvc\Model 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\Db. Phalcon\Logger interacts with Phalcon\Db, providing logging capabilities on the database abstraction layer, thus allowing us to log SQL statements as they happen.

<?php

use Phalcon\Db\Adapter\Pdo\Mysql;
use Phalcon\Di\FactoryDefault;
use Phalcon\Events\Manager;
use Phalcon\Logger;
use Phalcon\Logger\Adapter\Stream;

$container = new FactoryDefault();
$container->set(
    'db',
    function () {
        $eventsManager = new Manager();
        $adapter = new Stream('/storage/logs/db.log');
        $logger  = new Logger(
            'messages',
            [
                'main' => $adapter,
            ]
        );

        $eventsManager->attach(
            'db:beforeQuery',
            function ($event, $connection) use ($logger) {
                $logger->info(
                    $connection->getSQLStatement()
                );
            }
        );

        $connection = new Mysql\(
            [
                'host'     => 'localhost',
                'username' => 'root',
                'password' => 'secret',
                'dbname'   => 'phalcon',
            ]
        );

        $connection->setEventsManager($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:

<?php

use MyApp\Models\Invoices;

$invoice = new Invoices();
$invoice->inv_cst_id = 10;
$invoice->inv_title  = 'Invoice for ACME Inc.';
$invoice->inv_total  = 10000;

if ($invoice->save() === false) {
    echo 'Cannot save robot';
}

As above, the file /storage/logs/db.log will contain something like this:

[Mon, 30 Apr 12 13:47:18 -0500][DEBUG][Resource Id #77] INSERT INTO co_invoices (inv_cst_id, inv_title, inv_total) VALUES (10, 'Invoice for ACME Inc.', 10000)

Profiling SQL Statements

Using the Phalcon\Db, the underlying component of Phalcon\Mvc\Model, it is possible to profile the SQL statements generated by the ORM in order to analyze the performance of database operations. Analyzing the logs will help in identifying bottlenecks in your SQL code:

<?php

use Phalcon\Db\Profiler;
use Phalcon\Di\FactoryDefault;
use Phalcon\Events\Manager;
use Phalcon\Db\Adapter\Pdo;

$container = new FactoryDefault();
$container->set(
    'profiler',
    function () {
        return new Profiler();
    },
    true
);

$container->set(
    'db',
    function () use ($container) {
        $manager  = new Manager();
        $profiler = $container->getProfiler();

        $manager->attach(
            'db',
            function ($event, $connection) use ($profiler) {
                if ($event->getType() === 'beforeQuery') {
                    $profiler->startProfile(
                        $connection->getSQLStatement()
                    );
                }

                if ($event->getType() === 'afterQuery') {
                    $profiler->stopProfile();
                }
            }
        );

        $connection = new Mysql(
            [
                'host'     => 'localhost',
                'username' => 'root',
                'password' => 'secret',
                'dbname'   => 'phalcon',
            ]
        );

        // Assign the eventsManager to the db adapter instance
        $connection->setEventsManager($manager);

        return $connection;
    }
);

Profiling some queries:

<?php

use MyApp\Models\Invoices;

Invoices::find();
Invoices::find(
    [
        'order' => 'inv_cst_id, inv_title',
    ]
);
Invoices::find(
    [
        'limit' => 30,
    ]
);

$profiles = $container->get('profiler')->getProfiles();

foreach ($profiles as $profile) {
    echo 'SQL: ', 
        $profile->getSQLStatement(), 
        PHP_EOL,
        'Start: ',
        $profile->getInitialTime(),
        PHP_EOL,
        'Final: ',
        $profile->getFinalTime(),
        PHP_EOL,
        'Elapsed: ',
        $profile->getTotalElapsedSeconds(),
        PHP_EOL
    );
}

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