feature #14561 [FrameworkBundle][DX] Add option to specify additional translation loading paths (Seldaek)

This PR was squashed before being merged into the 2.8 branch (closes #14561).

Discussion
----------

[FrameworkBundle][DX] Add option to specify additional translation loading paths

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #971
| License       | MIT
| Doc PR        | TODO

Thanks to this PR, next time I want to just do:

```
    translator:
        fallback: "%locale%"
        paths: ['%kernel.root_dir%/../vendor/internal/package/translations']
```

I will be able to, and won't have to dig in docs, start building a translation loader before I realize it's not what I want, dig in the framework ext, and then have to write a compiler pass to inject my file to the translator resource paths.

Commits
-------

bba0a25 [FrameworkBundle][DX] Add option to specify additional translation loading paths

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

@@ -575,6 +575,7 @@ class Configuration implements ConfigurationInterface
                     ->info('translator configuration')
                     ->canBeEnabled()
                     ->fixXmlConfig('fallback')
+                    ->fixXmlConfig('path')
                     ->children()
                         ->arrayNode('fallbacks')
                             ->beforeNormalization()->ifString()->then(function ($v) { return array($v); })->end()
@@ -582,6 +583,9 @@ class Configuration implements ConfigurationInterface
                             ->defaultValue(array('en'))
                         ->end()
                         ->booleanNode('logging')->defaultValue($this->debug)->end()
+                        ->arrayNode('paths')
+                            ->prototype('scalar')->end()
+                        ->end()
                     ->end()
                 ->end()
             ->end()

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

@@ -692,6 +692,13 @@ class FrameworkExtension extends Extension
                 $dirs[] = $dir;
             }
         }
+        foreach ($config['paths'] as $dir) {
+            if (is_dir($dir)) {
+                $dirs[] = $dir;
+            } else {
+                throw new \UnexpectedValueException(sprintf('%s defined in translator.paths does not exist or is not a directory', $dir));
+            }
+        }
         if (is_dir($dir = $container->getParameter('kernel.root_dir').'/Resources/translations')) {
             $dirs[] = $dir;
         }

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

@@ -183,6 +183,7 @@
     <xsd:complexType name="translator">
         <xsd:sequence>
             <xsd:element name="fallback" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
+            <xsd:element name="path" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
         </xsd:sequence>
         <xsd:attribute name="enabled" type="xsd:boolean" />
         <xsd:attribute name="fallback" type="xsd:string" />

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

@@ -146,6 +146,7 @@ class ConfigurationTest extends \PHPUnit_Framework_TestCase
                 'enabled' => false,
                 'fallbacks' => array('en'),
                 'logging' => true,
+                'paths' => array(),
             ),
             'validation' => array(
                 'enabled' => false,

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

@@ -50,6 +50,7 @@ $container->loadFromExtension('framework', array(
     'translator' => array(
         'enabled' => true,
         'fallback' => 'fr',
+        'paths' => array('%kernel.root_dir%/Fixtures/translations'),
     ),
     'validation' => array(
         'enabled' => true,

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/translations/test_paths.en.yml

@@ -0,0 +1,2 @@
+custom:
+    paths: test

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

@@ -34,7 +34,9 @@
                  <framework:resource>theme2</framework:resource>
             </framework:form>
         </framework:templating>
-        <framework:translator enabled="true" fallback="fr" logging="true" />
+        <framework:translator enabled="true" fallback="fr" logging="true">
+            <framework:path>%kernel.root_dir%/Fixtures/translations</framework:path>
+        </framework:translator>
         <framework:validation enabled="true" cache="apc" />
         <framework:annotations cache="file" debug="true" file-cache-dir="%kernel.cache_dir%/annotations" />
         <framework:serializer enabled="true" />

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

@@ -39,6 +39,7 @@ framework:
     translator:
         enabled:  true
         fallback: fr
+        paths: ['%kernel.root_dir%/Fixtures/translations']
     validation:
         enabled: true
         cache:   apc

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

@@ -244,6 +244,11 @@ abstract class FrameworkExtensionTest extends TestCase
             $files,
             '->registerTranslatorConfiguration() finds Security translation resources'
         );
+        $this->assertContains(
+            strtr(__DIR__.'/Fixtures/translations/test_paths.en.yml', '/', DIRECTORY_SEPARATOR),
+            $files,
+            '->registerTranslatorConfiguration() finds translation resources in custom paths'
+        );
 
         $calls = $container->getDefinition('translator.default')->getMethodCalls();
         $this->assertEquals(array('fr'), $calls[0][1][0]);