Exactly how does the defaultValue work in Symfony 2.0 NodeDefinition? - php

Question

I'm trying to expose the semantic configuration within a bundle in Symfony 2.0 but I'm having trouble getting the defaultValue to work in the NodeDefinition class. I generated an empty bundle and created the necessary files for the Configuration to work and I am able to get the config value, but I want to set a defaultValue to configuration item. I use the defaultValue() method and remove the configuration item from my config.yml and then it shows up an empty array? Can anyone explain how the defaultValue() actually works, am I missing something?
<?php
// ./DependencyInjection/Configuration.php
namespace Test\Bundle\TestBundle\DependencyInjection;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;
use Symfony\Component\Config\Definition\ConfigurationInterface;
class Configuration implements ConfigurationInterface
{
public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('test_bundle');
$rootNode
->children()
->scalarNode('foo')->defaultValue('bar')->end()
->end();
return $treeBuilder;
}
}
-
<?php
// ./DependencyInjection/TestBundleExtension.php
namespace Test\Bundle\TestBundle\DependencyInjection;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\DependencyInjection\Loader;
class TestBundleExtension extends Extension
{
public function load(array $configs, ContainerBuilder $container)
{
$configuration = new Configuration();
$config = $this->processConfiguration($configuration, $configs);
var_dump($configs); // empty array
$loader = new Loader\XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
$loader->load('services.xml');
}
}
So from the above Configuration class surely when the config item 'test_bundle.foo' is missing, it's value will be set to 'bar'... yes? Well that's what I thought but it doesn't.

Answer 1

Your root node is an array node. By default, if you dont set a key, default value is not applied. 2 examples on how to get your default value working:
Set the value as null:
# in the config.yml
test_bundle:
foo: ~
Tell your root node to use default values if not set:
// in your Configuration.php
$rootNode
->addDefaultsIfNotSet()
->children()
->scalarNode('foo')->defaultValue('bar')->end()
->end();
# in the config.yml
test_bundle: ~