Chapter 18. Plugins

18.1. Events

CompatInfo uses a Symfony EventDispatcher Component to allow you to easily extend the features list.

The EventDispatcher component allow CompatInfo components to communicate with each other by dispatching events and listening to them.

18.1.1. Event Dispatcher

CompatInfo implement interface Bartlett\Reflect\Event\DispatcherInterface. You can add event listeners and event subscribers to this object.

listeners

Callable functions that are registered on an event dispatcher for specific events.

subscribers

Classes that tell an event dispatcher what methods to listen to and what functions on the class to invoke when the event is triggered. Event subscribers subscribe event listeners to an event dispatcher.

18.1.2. Getting an EventDispatcher

You can get the EventDispatcher of Bartlett\Reflect\Event\DispatcherInterface by calling the getEventDispatcher() method.

Here is an example :

<?php

use Bartlett\Reflect\Client;

// creates an instance of client
$client = new Client();

// request for a Bartlett\Reflect\Api\Analyser
$api = $client->api('analyser');

$dispatcher = $api->getEventDispatcher();

18.1.3. Adding Event Listeners

After you have the event dispatcher, you can register event listeners that listen to specific events.

Example 18.1. Add a listener that will echo out files when they are parsed

<?php

use Bartlett\Reflect\Client;

use Symfony\Component\EventDispatcher\GenericEvent;

// creates an instance of client
$client = new Client();

// request for a Bartlett\Reflect\Api\Analyser
$api = $client->api('analyser');

$dispatcher = $api->getEventDispatcher();

$dispatcher->addListener(
    'reflect.progress',
    function (GenericEvent $e) {
        printf(
            'Parsing Data source "%s" in progress ... File "%s"' . PHP_EOL,
            $e['source'],
            $e['file']->getPathname()
        );
    }
);

18.1.4. Event Subscribers

Event subscribers are classes that implement interface Symfony\Component\EventDispatcher\EventSubscriberInterface. They are used to register one or more event listeners to methods of the class. Event subscribers tell event dispatcher exactly which events to listen to and what method to invoke on the class.

CompatInfo plugins follow the event subscribers behaviors. Have a look on NotifierPlugin :

<?php

use Bartlett\Reflect\Events;

class NotifierPlugin implements PluginInterface, EventSubscriberInterface
{
    public static function getSubscribedEvents()
    {
        $events = array(
            Events::PROGRESS => 'onNotification',
            Events::ERROR    => 'onNotification',
            Events::COMPLETE => 'onNotification',
        );
        return $events;
    }
}

This plugin registers event listeners to the reflect.complete event of a Reflect parse request.

When the reflect.complete event is emitted, the onNotification instance method of the plugin is invoked.

18.1.5. Events lifecycle

Event Action Informations available

reflect.progess

Before to parse a new file of the data source.

source data source identifier or its alias file current file parsed in the data source

reflect.success

After parsing the current file ( A cached request will not trigger this event )

source data source identifier or its alias file current file parsed in the data source ast the Abstract Syntax Tree result of PHP-Parser

reflect.error

When PHP Parser raise an error

source data source identifier or its alias file current file parsed in the data source error PHP Parser error message

reflect.complete

When a parse request is over.

source data source identifier or its alias

18.2. Register Plugins

[Note]

In Reflect API 2, and other SAPI than CLI, you have to register a plugin, if you want to use it.

In Reflect API 3, it’s no more necessary. All valid plugins defined in the JSON configuration file are automatically registered.

[Important]

You must define environment variables BARTLETT_SCAN_DIR and BARTLETTRC, otherwise the JSON config file will not found it.

If you don’t want to use any plugins, and de-activated all at once, follow this pattern.

<?php

use Bartlett\Reflect\Environment;
use Bartlett\Reflect\Client;

// set default values for BARTLETT_SCAN_DIR
Environment::setScanDir()

// set default value for BARTLETTRC
putenv("BARTLETTRC=phpcompatinfo.json");

// creates an instance of client
$client = new Client();

// request for a Bartlett\Reflect\Api\Analyser
$api = $client->api('analyser');

// de activate all plugins
$api->activatePlugins(false);

// perform request, on a data source with default analyser (compatibility)
$dataSource = dirname(__DIR__) . '/src';
$analysers  = array('compatibility');

// equivalent to CLI command `phpcompatinfo analyser:run ../src`
$metrics = $api->run($dataSource, $analysers);