seiffert / helper-bundle
This bundle provides a structure for helper objects.
Requires
- php: >=5.3.3
- symfony/framework-bundle: >=2.1.0,<2.3-dev
Requires (Dev)
- pdepend/pdepend: 1.1.0
- phpmd/phpmd: 1.4.0
- phpunit/php-code-coverage: 1.2.*
- phpunit/php-timer: 1.0.4
- phpunit/phpunit: 3.7.*
- squizlabs/php_codesniffer: *
This package is not auto-updated.
Last update: 2024-11-09 15:28:49 UTC
README
This bundle introduces a structure for helper objects.
Concepts
After developing Symfony2 applications for quite some time, I stumbled upon different use cases for some kind of helper objects. One of them for instance are controllers: As soon as you stop to use FrameworkBundle's default controller as base class for your controllers, you probably start writing code that replaces the helper functions in the default controller. This code will probably be required in most of your controllers. In this situation, you either create controller classes that all have a lot of dependencies that are injected by the DIC, you re-introduce a base controller class, or you employ some kind of helper objects.
This bundle solves this kind of situations by introducing helper objects that are managed by the dependency injection container (thus they are created lazily and will be reused) and are made available via a single helper object - the HelperBroker. One broker aggregates multiple helpers that are collected and configured during container compilation and proxies calls to helper methods to the actual helper objects.
Setup
Require the package via composer:
composer.json:
"require": {
...
"seiffert/helper-bundle": "*",
...
}
Activate the bundle in your AppKernel:
app/AppKernel.php:
public function registerBundles()
{
$bundles = array(
...
new Seiffert\HelperBundle\SeiffertHelperBundle(),
...
);
...
}
Usage
There are different ways of using helpers and helper brokers. In the following, I will explain the two, which appear most useful to me.
via tagged service
To configure helpers as services, you just implement your custom helper classes, add definitions for them to the DIC, and tag them like this:
services:
my.helper:
class: My\Helper\MyHelper
tags:
- { name: seiffert.helper, broker: my.helper.broker }
my.second.helper:
class: My\Helper\MySecondHelper
tags:
- { name: seiffert.helper, broker: my.helper.broker }
my.service.that.requires.help:
class: My\Service\ThatRequiresHelpService
arguments:
- @my.helper.broker
The argument injected into the class My\Service\ThatRequiresHelpService is of type Seiffert\HelperBundle\HelperBroker and answers to all methods defined in your helper classes My\Helper\MySecondHelper and My\Helper\MyHelper. This is done by proxying these method calls to the actual helper classes using __call.
To further illustrate the usage of a helper broker using the same scenario as above, I will sketch out the mentioned classes:
My\Helper\MyHelper:
<?php
namespace My\Helper;
use Seiffert\HelperBundle\HelperInterface;
class MyHelper implements HelperInterface
{
public static function getHelperMethodNames()
{
return array('fooHelp');
}
public function fooHelp()
{
return 'foo';
}
}
My\Helper\MySecondHelper:
<?php
namespace My\Helper;
use Seiffert\HelperBundle\HelperInterface;
class MySecondHelper implements HelperInterface
{
public static function getHelperMethodNames()
{
return array('barHelp');
}
public function barHelp()
{
return 'bar';
}
}
My\Service\ThatRequiresHelpService:
<?php
namespace My\Service;
use Seiffert\HelperBundle\HelperBroker;
class ThatRequiresHelperService
{
/**
* @var HelperBroker $h
*/
private $h;
public function __construct(HelperBroker $helper)
{
$this->h = $helper;
}
public function doYourJob()
{
return $this->h->fooHelp() . '|' . $this->h->barHelp();
}
}
By using helper brokers, you can minimize the dependencies of your own services and group helpers that are required in similar situations. Examples of helper classes can be found in the related SeiffertControllerHelperBundle.
via helper sets
Another way of configuring a helper broker is to instantiate it with a helper set. A helper set is a collection of helper objects that knows how to add its helpers to a helper broker. The good thing with helper sets is that you can put the instantiation of all your helpers in one place (which is not as important as putting it outside of your business logic, where you are using these helpers). This place is your custom subclass of Seiffert\HelperBundle\HelperSet:
My\HelperSet:
<?php
namespace My;
use Seiffert\HelperBundle\HelperSet as BaseHelperSet;
class HelperSet extends BaseHelperSet
{
/**
* @return array|object[]
*/
public function getHelpers()
{
return array(
new MyHelper(),
new MySecondHelper()
);
}
}
Now if you want to create a helper broker with this set, you just have to pass an instance of it to the helper broker's constructor:
Somewhere else:
<?php
use My\HelperSet;
use Seiffert\HelperBundle\HelperBroker;
$h = new HelperBroker(new HelperSet());
echo $h->fooHelp();
Advanced Topics
Helper classes not implementing HelperInterface
It is possible to use classes for helper objects that don't implement Seiffert\HelperBundle\HelperInterface. In this case, all public methods of such a class will be made available through the helper broker.
Default broker
If you don't add the attribute broker to you helper service's tag, the helper is added to a broker defined as seiffert.helper.broker.
Register helper objects at multiple brokers
Helpers can be used by multiple brokers. To do so, just duplicate the helper's tag seiffert.helper and declare different brokers:
services:
my.helper:
class: My\Helper\MyHelper
tags:
- { name: seiffert.helper, broker: my.helper.broker }
- { name: seiffert.helper, broker: my.other.helper.broker }