Now that we have a compilation phase for the DIC, using tags after compilation
is not needed anymore.
Tags were introduced to allow several independant bundles to be able to
interact which each others (remember that each extension knows nothing about
the others).
But during the compilation phase, the container has been merged ans so, all
the information from all bundles are available. This is then the right place
to deal with tags. That way, less work is needed at runtime and the DIC class
in the cache is also much smaller.
For simple cases, it means that you need to process the tag in a compiler pass
and store the information you need in a DIC parameter (have a look at the
TranslatorPass for a very simple example).
So, the PHP dumper does not add tags to the dumped PHP class anymore (it does
not implements TaggedContainerInterface anymore). But tags are still available
on ContainerBuilder instances.
Let's take some examples to explain the change.
First, if you don't use any vendored bundles, this commit does not change anything.
So, let's say you use a FooBundle from Sensio. The files are stored under Bundle\Sensio\FooBundle.
And the Bundle class is Bundle\Sensio\FooBundle\SensioFooBundle.php.
Before the change, the bundle name ($bundle->getName()) would have returned 'FooBundle'.
Now it returns 'SensioFooBundle'.
Why does it matter? Well, it makes template names and controller names easier to read:
Before:
Template: Sensio\FooBundle:Bar:index.twig.html
Controller: Sensio\FooBundle:Bar:indexAction
After
Template: SensioFooBundle:Bar:index.twig.html
Controller: SensioFooBundle:Bar:indexAction
NB: Even if the change seems simple enough, the implementation is not. As finding
the namespace from the bundle class name is not trivial
NB2: If you don't follow the bundle name best practices, this will probably
leads to unexpected behaviors.
Before
bundle:section:template.format.renderer
After
bundle:section:template.renderer.format
Notice that both the renderer and the format are mandatory.
* better separation of concerns
* made TwigBundle independant of the PHP Engine from FrameworkBundle (WIP)
* removed one layer of abstraction in the Templating component (renderers)
* made it easier to create a new Engine for any templating library
* made engines lazy-loaded (PHP engine for instance is not started if you only use Twig)
* reduces memory footprint (if you only use one engine)
* reduces size of compiled classes.php cache file
