bug symfony#19120 [FrameworkBundle] templating can be fully disabled (xabbuh)

This PR was submitted for the master branch but it was merged into the 3.1 branch instead (closes symfony#19120).

Discussion
----------

[FrameworkBundle] templating can be fully disabled

| Q             | A
| ------------- | ---
| Branch?       | 3.1
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | symfony#19052
| License       | MIT
| Doc PR        |

Commits
-------

92a7f10 [FrameworkBundle] templating can be fully disabled

Author: fabpot

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -320,6 +320,10 @@ private function addTemplatingSection(ArrayNodeDefinition $rootNode)
                 ->arrayNode('templating')
                     ->info('templating configuration')
                     ->canBeEnabled()
+                    ->beforeNormalization()
+                        ->ifTrue(function ($v) { return false === $v || is_array($v) && false === $v['enabled']; })
+                        ->then(function () { return array('enabled' => false, 'engines' => false); })
+                    ->end()
                     ->children()
                         ->scalarNode('hinclude_default_template')->defaultNull()->end()
                         ->scalarNode('cache')->end()
@@ -346,8 +350,9 @@ private function addTemplatingSection(ArrayNodeDefinition $rootNode)
                             ->example(array('twig'))
                             ->isRequired()
                             ->requiresAtLeastOneElement()
+                            ->canBeUnset()
                             ->beforeNormalization()
-                                ->ifTrue(function ($v) { return !is_array($v); })
+                                ->ifTrue(function ($v) { return !is_array($v) && false !== $v; })
                                 ->then(function ($v) { return array($v); })
                             ->end()
                             ->prototype('scalar')->end()

src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd

@@ -147,10 +147,11 @@
     <xsd:complexType name="templating">
         <xsd:sequence>
             <xsd:element name="loader" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
-            <xsd:element name="engine" type="xsd:string" minOccurs="1" maxOccurs="unbounded" />
+            <xsd:element name="engine" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
             <xsd:element name="form" type="form-resources" minOccurs="0" maxOccurs="1" />
         </xsd:sequence>
 
+        <xsd:attribute name="enabled" type="xsd:boolean" />
         <xsd:attribute name="cache" type="xsd:string" />
         <xsd:attribute name="hinclude-default-template" type="xsd:string" />
     </xsd:complexType>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/php/templating_disabled.php

@@ -0,0 +1,5 @@
+<?php
+
+$container->loadFromExtension('framework', array(
+    'templating' => false,
+));

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/xml/templating_disabled.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" ?>
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:framework="http://symfony.com/schema/dic/symfony"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
+        http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
+    <framework:config>
+        <framework:templating enabled="false" />
+    </framework:config>
+</container>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/templating_disabled.yml

@@ -0,0 +1,2 @@
+framework:
+    templating: false

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -208,6 +208,13 @@ public function testTemplating()
         $this->assertEquals('global_hinclude_template', $container->getParameter('fragment.renderer.hinclude.global_template'), '->registerTemplatingConfiguration() registers the global hinclude.js template');
     }
 
+    public function testTemplatingCanBeDisabled()
+    {
+        $container = $this->createContainerFromFile('templating_disabled');
+
+        $this->assertFalse($container->hasParameter('templating.engines'), '"templating.engines" container parameter is not registered when templating is disabled.');
+    }
+
     public function testAssets()
     {
         $container = $this->createContainerFromFile('assets');