Add date format field

DependencyInjection/Configuration.php

@@ -325,7 +325,8 @@ class Configuration implements ConfigurationInterface
                     ->scalarNode('type')->end()
                     ->scalarNode('identifier')->defaultValue('id')->end()
                 ->end()
-            ->end();
+            ->end()
+            ->scalarNode('format')->end();
 
         if (isset($nestings['fields'])) {
             $this->addNestedFieldConfig($node, $nestings, 'fields');

README.md

@@ -666,3 +666,21 @@ fos_elastica:
                         provider:
                         finder:
 ```
+
+#### Date format example
+
+If you want to specify a [date format](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/mapping-date-format.html):
+
+```yaml
+fos_elastica:
+    clients:
+        default: { host: localhost, port: 9200 }
+    indexes:
+        site:
+            types:
+                user:
+                    mappings:
+                        username: { type: string }
+                        lastlogin: { type: date, format: basic_date_time }
+                        birthday: { type: date, format: "yyyy-MM-dd" }
+```

Tests/DependencyInjection/ConfigurationTest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace FOS\ElasticaBundle\Tests\Resetter\DependencyInjection;
+
+use FOS\ElasticaBundle\DependencyInjection\Configuration;
+
+/**
+ * ConfigurationTest
+ */
+class ConfigurationTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var Configuration
+     */
+    private $configuration;
+
+    public function setUp()
+    {
+        $this->configuration = new Configuration(array());
+    }
+
+    public function testEmptyConfigContainsFormatMappingOptionNode()
+    {
+        $tree = $this->configuration->getConfigTree();
+        $children = $tree->getChildren();
+        $children = $children['indexes']->getPrototype()->getChildren();
+        $typeNodes = $children['types']->getPrototype()->getChildren();
+        $mappings = $typeNodes['mappings']->getPrototype()->getChildren();
+
+        $this->assertArrayHasKey('format', $mappings);
+        $this->assertInstanceOf('Symfony\Component\Config\Definition\ScalarNode', $mappings['format']);
+        $this->assertNull($mappings['format']->getDefaultValue());
+    }
+}