With this refactoring comes a decoupling of the validator from the structure of
the underlying metadata. This way it is possible for Drupal to use the validator
for validating their Entity API by using their own metadata layer, which is not
modeled as classes and properties/getter methods.
The extension classes are now the only constructor argument of the FormFactory class. They replace the existing "type loader" classes.
new FormFactory(array(
new CoreExtension($validator, $storage),
new CsrfExtension($csrfProvider),
new DoctrineOrmExtension($em),
));
Together with a few upcoming commits this mechanism will make
* extension of the form framework in bundles and
* usage of the forms outside of Symfony2
much easier.