The PSR-0 Class Loader
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The PSR-0 Class Loader
2.1
The ClassLoader class was introduced in Symfony 2.1.
If your classes and third-party libraries follow the PSR-0 standard, you can use the ClassLoader class to load all of your project's classes.
Tip
You can use both the ApcClassLoader and the XcacheClassLoader
to cache a ClassLoader
instance or the DebugClassLoader to debug
it.
Usage
Registering the ClassLoader autoloader is straightforward:
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require_once '/path/to/src/Symfony/Component/ClassLoader/ClassLoader.php';
use Symfony\Component\ClassLoader\ClassLoader;
$loader = new ClassLoader();
// to enable searching the include path (eg. for PEAR packages)
$loader->setUseIncludePath(true);
// ... register namespaces and prefixes here - see below
$loader->register();Note
The autoloader is automatically registered in a Symfony application
(see app/autoload.php).
Use addPrefix() or addPrefixes() to register your classes:
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// register a single namespaces
$loader->addPrefix('Symfony', __DIR__.'/vendor/symfony/symfony/src');
// register several namespaces at once
$loader->addPrefixes(array(
'Symfony' => __DIR__.'/../vendor/symfony/symfony/src',
'Monolog' => __DIR__.'/../vendor/monolog/monolog/src',
));
// register a prefix for a class following the PEAR naming conventions
$loader->addPrefix('Twig_', __DIR__.'/vendor/twig/twig/lib');
$loader->addPrefixes(array(
'Swift_' => __DIR__.'/vendor/swiftmailer/swiftmailer/lib/classes',
'Twig_' => __DIR__.'/vendor/twig/twig/lib',
));Classes from a sub-namespace or a sub-hierarchy of PEAR classes can be looked for in a location list to ease the vendoring of a sub-set of classes for large projects:
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$loader->addPrefixes(array(
'Doctrine\\Common' => __DIR__.'/vendor/doctrine/common/lib',
'Doctrine\\DBAL\\Migrations' => __DIR__.'/vendor/doctrine/migrations/lib',
'Doctrine\\DBAL' => __DIR__.'/vendor/doctrine/dbal/lib',
'Doctrine' => __DIR__.'/vendor/doctrine/orm/lib',
));In this example, if you try to use a class in the Doctrine\Common namespace
or one of its children, the autoloader will first look for the class under
the doctrine-common directory. If not found, it will then fallback to
the default Doctrine directory (the last one configured) before giving
up. The order of the prefix registrations is significant in this case.
