[DX] Improve configuration validation

The two nodes elastica_to_model_transformer.hydrate and
elastica_to_model_transformer.ignore_missing must be boolean values but
this was not validated in the configuration.

This early validation provides better feedback to the developer who
supplied an invalid configuration.

Author: David Fuhr

DependencyInjection/Configuration.php

@@ -538,8 +538,11 @@ protected function getPersistenceNode()
                 ->arrayNode('elastica_to_model_transformer')
                     ->addDefaultsIfNotSet()
                     ->children()
-                        ->scalarNode('hydrate')->defaultTrue()->end()
-                        ->scalarNode('ignore_missing')->defaultFalse()->end()
+                        ->booleanNode('hydrate')->defaultTrue()->end()
+                        ->booleanNode('ignore_missing')
+                            ->defaultFalse()
+                            ->info('Silently ignore results returned from Elasticsearch without corresponding persistent object.')
+                        ->end()
                         ->scalarNode('query_builder_method')->defaultValue('createQueryBuilder')->end()
                         ->scalarNode('service')->end()
                     ->end()

Resources/doc/usage.md

@@ -11,6 +11,7 @@ configuration options for this kind of searching, please see the [types](types.m
 documentation.
 
 ```php
+/* @var $finder \FOS\ElasticaBundle\Finder\TransformedFinder */
 $finder = $this->container->get('fos_elastica.finder.search.user');
 
 // Option 1. Returns all users who have example.net in any of their mapped fields