发布于 2015-08-27 16:46:43 | 217 次阅读 | 评论: 0 | 来源: 网络整理
You have seen how to use configuration parameters within
Symfony service containers.
There are special cases such as when you want, for instance, to use the
%kernel.debug% parameter to make the services in your bundle enter
debug mode. For this case there is more work to do in order
to make the system understand the parameter value. By default
your parameter %kernel.debug% will be treated as a
simple string. Consider this example with the AcmeDemoBundle:
// Inside Configuration class
$rootNode
->children()
->booleanNode('logging')->defaultValue('%kernel.debug%')->end()
// ...
->end()
;
// Inside the Extension class
$config = $this->processConfiguration($configuration, $configs);
var_dump($config['logging']);
Now, examine the results to see this closely:
my_bundle:
logging: true
# true, as expected
my_bundle:
logging: "%kernel.debug%"
# true/false (depends on 2nd parameter of AppKernel),
# as expected, because %kernel.debug% inside configuration
# gets evaluated before being passed to the extension
my_bundle: ~
# passes the string "%kernel.debug%".
# Which is always considered as true.
# The Configurator does not know anything about
# "%kernel.debug%" being a parameter.
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:my-bundle="http://example.org/schema/dic/my_bundle">
<my-bundle:config logging="true" />
<!-- true, as expected -->
<my-bundle:config logging="%kernel.debug%" />
<!-- true/false (depends on 2nd parameter of AppKernel),
as expected, because %kernel.debug% inside configuration
gets evaluated before being passed to the extension -->
<my-bundle:config />
<!-- passes the string "%kernel.debug%".
Which is always considered as true.
The Configurator does not know anything about
"%kernel.debug%" being a parameter. -->
</container>
$container->loadFromExtension('my_bundle', array(
'logging' => true,
// true, as expected
)
);
$container->loadFromExtension('my_bundle', array(
'logging' => "%kernel.debug%",
// true/false (depends on 2nd parameter of AppKernel),
// as expected, because %kernel.debug% inside configuration
// gets evaluated before being passed to the extension
)
);
$container->loadFromExtension('my_bundle');
// passes the string "%kernel.debug%".
// Which is always considered as true.
// The Configurator does not know anything about
// "%kernel.debug%" being a parameter.
In order to support this use case, the Configuration class has to
be injected with this parameter via the extension as follows:
namespace AcmeDemoBundleDependencyInjection;
use SymfonyComponentConfigDefinitionBuilderArrayNodeDefinition;
use SymfonyComponentConfigDefinitionBuilderTreeBuilder;
use SymfonyComponentConfigDefinitionConfigurationInterface;
class Configuration implements ConfigurationInterface
{
private $debug;
public function __construct($debug)
{
$this->debug = (Boolean) $debug;
}
public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root('acme_demo');
$rootNode
->children()
// ...
->booleanNode('logging')->defaultValue($this->debug)->end()
// ...
->end()
;
return $treeBuilder;
}
}
And set it in the constructor of Configuration via the Extension class:
namespace AcmeDemoBundleDependencyInjection;
use SymfonyComponentDependencyInjectionContainerBuilder;
use SymfonyComponentDependencyInjectionLoaderXmlFileLoader;
use SymfonyComponentHttpKernelDependencyInjectionExtension;
use SymfonyComponentConfigFileLocator;
class AcmeDemoExtension extends Extension
{
// ...
public function getConfiguration(array $config, ContainerBuilder $container)
{
return new Configuration($container->getParameter('kernel.debug'));
}
}