Symfony 2.1 Extending Core Classes - php

Question

I am trying to override the core Symfony components with my own. The method I am using is:
"autoload": {
"psr-0": {
"": "src/",
"Symfony": "src/vendor/symfony/src/"
}
}
However when I run composer update and install it never seems to take this into account. Is this not the correct method to force the autoloader to look into another directory first before the Symfony core?
Any pointers appreciated!
EDIT: Paths to files
src/vendor/symfony/src/Symfony/Bridge/Twig/Extension/TranslationExtension.php
src/vendor/symfony/src/Symfony/Component/Translation/Translator.php
src/vendor/symfony/src/Symfony/Component/Translation/Loader/YamlFileLoader.php
<?php
// autoload_namespaces.php generated by Composer
$vendorDir = dirname(__DIR__);
$baseDir = dirname($vendorDir);
return array(
'Twig_Extensions_' => $vendorDir . '/twig/extensions/lib/',
'Twig_' => $vendorDir . '/twig/twig/lib/',
'Symfony\\Bundle\\SwiftmailerBundle' => $vendorDir . '/symfony/swiftmailer-bundle/',
'Symfony\\Bundle\\MonologBundle' => $vendorDir . '/symfony/monolog-bundle/',
'Symfony\\Bundle\\AsseticBundle' => $vendorDir . '/symfony/assetic-bundle/',
'Symfony' => array($vendorDir . '/symfony/symfony/src/', '/src/vendor/symfony/src/'),
'SessionHandlerInterface' => $vendorDir . '/symfony/symfony/src/Symfony/Component/HttpFoundation/Resources/stubs',
'Sensio\\Bundle\\GeneratorBundle' => $vendorDir . '/sensio/generator-bundle/',
'Sensio\\Bundle\\FrameworkExtraBundle' => $vendorDir . '/sensio/framework-extra-bundle/',
'Sensio\\Bundle\\DistributionBundle' => $vendorDir . '/sensio/distribution-bundle/',
'Monolog' => $vendorDir . '/monolog/monolog/src/',
'Metadata\\' => $vendorDir . '/jms/metadata/src/',
'JMS\\SecurityExtraBundle' => $vendorDir . '/jms/security-extra-bundle/',
'JMS\\DiExtraBundle' => $vendorDir . '/jms/di-extra-bundle/',
'JMS\\AopBundle' => $vendorDir . '/jms/aop-bundle/',
'Doctrine\\ORM' => $vendorDir . '/doctrine/orm/lib/',
'Doctrine\\DBAL' => $vendorDir . '/doctrine/dbal/lib/',
'Doctrine\\Common' => $vendorDir . '/doctrine/common/lib/',
'Doctrine\\Bundle\\DoctrineBundle' => $vendorDir . '/doctrine/doctrine-bundle/',
'CG\\' => $vendorDir . '/jms/cg/src/',
'Assetic' => $vendorDir . '/kriswallsmith/assetic/src/',
'' => $baseDir . '/src/',
);
If I manually edit the autoload line to:
'Symfony' => array('/Users/macbook/Sites/Opia/Gaia/src/vendor/symfony/src/', $vendorDir . '/symfony/symfony/src/'),
Everything works as it is meant to. So now it is basically finding the solution to why composer does not compose properly.
EDIT 2:
Doing some more searching it appears the above method is not a good implementation:
https://groups.google.com/forum/#!msg/composer-dev/HprRV_wJZg4/M_zQ8O7lB6IJ
Instead I need to extend the given classes and tell Symfony to use those classes instead which should be possible through the parameters:
parameters:
security.authentication.listener.anonymous.class: Acme\DemoBundle
\Security\Http\Firewall\AcmeAnonymousAuthenticationListener
However I am not sure what parameters I need to set to load the extended classes in place of the core.

Answer 1

I finally found the answer to this.
Firstly if you need to find out which classes to override go to:
symfony/src/Symfony/Bundle/FrameworkBundle/Resources/%Your file to override%.xml
There you will find a list of possible Symfony classes that can be extended/overridden.
Then in your config.yml add (I chose to put mine in an extend namespace):
parameters:
twig.extension.trans.class: Extend\Symfony\Bridge\Twig\Extension\TranslationExtension
translation.loader.yml.class: Extend\Symfony\Component\Translation\Loader\YamlFileLoader
translator.class: Extend\Symfony\Bundle\FrameworkBundle\Translation\Translator
Finally in my composer.json:
"autoload": {
"psr-0": {
"": "src/",
"Extend\\Symfony": "/path/to/your/symfony/classes"
}
},