Merge pull request FriendsOfSymfony#1084 from mickadoo/feature/use_de…

…fault_configuration

[FriendsOfSymfony#1083] Make orm, provider, listener and finder optional.

DependencyInjection/Configuration.php

@@ -507,15 +507,17 @@ protected function getPersistenceNode()
             ->end()
             ->children()
                 ->scalarNode('driver')
+                    ->defaultValue('orm')
                     ->validate()
                     ->ifNotInArray($this->supportedDrivers)
                         ->thenInvalid('The driver %s is not supported. Please choose one of '.json_encode($this->supportedDrivers))
                     ->end()
                 ->end()
-                ->scalarNode('model')->end()
+                ->scalarNode('model')->defaultValue(null)->end()
                 ->scalarNode('repository')->end()
                 ->scalarNode('identifier')->defaultValue('id')->end()
                 ->arrayNode('provider')
+                    ->addDefaultsIfNotSet()
                     ->children()
                         ->scalarNode('batch_size')->defaultValue(100)->end()
                         ->scalarNode('clear_object_manager')->defaultTrue()->end()
@@ -528,6 +530,7 @@ protected function getPersistenceNode()
                     ->end()
                 ->end()
                 ->arrayNode('listener')
+                    ->addDefaultsIfNotSet()
                     ->children()
                         ->scalarNode('insert')->defaultTrue()->end()
                         ->scalarNode('update')->defaultTrue()->end()
@@ -543,6 +546,7 @@ protected function getPersistenceNode()
                     ->end()
                 ->end()
                 ->arrayNode('finder')
+                    ->addDefaultsIfNotSet()
                     ->children()
                         ->scalarNode('service')->end()
                     ->end()