Description
Symfony Config component makes it possible to define semantic configuration, exposed to the end developer. This configuration is validated by rules you define, e.g. validating type (string, array, integer, boolean, etc.). Usually, once validated and processed, this semantic configuration is then mapped to internal key/value parameters stored in the ServiceContainer.
eZ Platform uses this for its core configuration, but adds another configuration level, the siteaccess. For each defined siteaccess, we need to be able to use the same configuration tree in order to define siteaccess-specific config. These settings then need to be mapped to siteaccess-aware internal parameters that you can retrieve via the ConfigResolver. For this, internal keys need to follow the format <namespace>.<scope>.<parameter_name>, namespace being specific to your app/bundle, scope being the siteaccess, siteaccess group, default or global, parameter_name being the actual setting identifier.
The goal of this feature is to make it easy to implement a siteaccess-aware semantic configuration and its mapping to internal config for any eZ bundle developer.
Solution
Semantic configuration parsing
An abstract Configuration class has been added, simplifying the way to add a siteaccess settings tree like the following:
| Code Block |
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| language | bash |
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| title | ezplatform.yml or config.yml |
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acme_demo:
system:
my_siteaccess:
hello: "world"
foo_setting:
an_integer: 456
enabled: true
my_siteaccess_group:
hello: "universe"
foo_setting:
foo: "bar"
some: "thing"
an_integer: 123
enabled: false |
Class FQN is eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\Configuration.
All you have to do is to extend it and use $this->generateScopeBaseNode():
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namespace Acme\DemoBundle\DependencyInjection;
use eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\Configuration as SiteAccessConfiguration;
use Symfony\Component\Config\Definition\Builder\NodeBuilder;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;
class Configuration extends SiteAccessConfiguration
{
public function getConfigTreeBuilder()
{
$treeBuilder = new TreeBuilder();
$rootNode = $treeBuilder->root( 'acme_demo' );
// $systemNode will then be the root of siteaccess aware settings.
$systemNode = $this->generateScopeBaseNode( $rootNode );
$systemNode
->scalarNode( 'hello' )->isRequired()->end()
->arrayNode( 'foo_setting' )
->children()
->scalarNode( "foo" )->end()
->scalarNode( "some" )->end()
->integerNode( "an_integer" )->end()
->booleanNode( "enabled" )->end()
->end()
->end();
return $treeBuilder;
}
} |
| Info |
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Default name for the siteaccess root node is system, but you can customize it. For this, just pass the name you want to use as a second argument of $this->generateScopeBaseNode(). |
Mapping to internal settings
Semantic configuration must always be mapped to internal key/value settings within the ServiceContainer. This is usually done in the DIC extension.
For siteaccess-aware settings, new ConfigurationProcessor and Contextualizer classes have been introduced to ease the process.
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namespace Acme\DemoBundle\DependencyInjection;
use eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\ConfigurationProcessor;
use eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\ContextualizerInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\DependencyInjection\Loader;
/**
* This is the class that loads and manages your bundle configuration
*
* To learn more see {@link http://symfony.com/doc/current/cookbook/bundles/extension.html}
*/
class AcmeDemoExtension extends Extension
{
public function load( array $configs, ContainerBuilder $container )
{
$configuration = $this->getConfiguration( $configs, $container );
$config = $this->processConfiguration( $configuration, $configs );
$loader = new Loader\YamlFileLoader( $container, new FileLocator( __DIR__.'/../Resources/config' ) );
$loader->load( 'default_settings.yml' );
// "acme_demo" will be the namespace as used in ConfigResolver format.
$processor = new ConfigurationProcessor( $container, 'acme_demo' );
$processor->mapConfig(
$config,
// Any kind of callable can be used here.
// It will be called for each declared scope/SiteAccess.
function ( $scopeSettings, $currentScope, ContextualizerInterface $contextualizer )
{
// Will map "hello" setting to "acme_demo.<$currentScope>.hello" container parameter
// It will then be possible to retrieve this parameter through ConfigResolver in the application code:
// $helloSetting = $configResolver->getParameter( 'hello', 'acme_demo' );
$contextualizer->setContextualParameter( 'hello', $currentScope, $scopeSettings['hello'] );
}
);
// Now map "foo_setting" and ensure keys defined for "my_siteaccess" overrides the one for "my_siteaccess_group"
// It is done outside the closure as it is needed only once.
$processor->mapConfigArray( 'foo_setting', $config );
}
} |
| Tip |
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You can map simple settings by calling $processor->mapSetting(), without having to call $processor->mapConfig() with a callable. | Code Block |
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| $processor = new ConfigurationProcessor( $container, 'acme_demo' );
$processor->mapSetting( 'hello', $config ); |
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| Warning |
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Always ensure you have defined and loaded default settings. |
| Code Block |
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| language | bash |
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| title | @AcmeDemoBundle/Resources/config/default_settings.yml |
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parameters:
acme_demo.default.hello: world
acme_demo.default.foo_setting:
foo: ~
some: ~
planets: [Earth]
an_integer: 0
enabled: false
j_adore: les_sushis |
Merging hash values between scopes
When you define a hash as semantic config, you sometimes don't want the siteaccess settings to replace the default or group values, but enrich them by appending new entries. This is made possible by using $processor->mapConfigArray(), which needs to be called outside the closure (before or after), in order to be called only once.
Consider the following default config:
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| language | bash |
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| title | default_settings.yml |
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parameters:
acme_demo.default.foo_setting:
foo: ~
some: ~
planets: [Earth]
an_integer: 0
enabled: false
j_adore: les_sushis |
And then this semantic config:
| Code Block |
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| language | bash |
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| title | ezplatform.yml or config.yml |
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acme_demo:
system:
sa_group:
foo_setting:
foo: bar
some: thing
an_integer: 123
# Assuming "sa1" is part of "sa_group"
sa1:
foo_setting:
an_integer: 456
enabled: true
j_adore: le_saucisson |
What we want here is that keys defined for foo_setting are merged between default/group/siteaccess:
| Code Block |
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| language | bash |
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| title | Expected result |
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parameters:
acme_demo.sa1.foo_setting:
foo: bar
some: thing
planets: [Earth]
an_integer: 456
enabled: true
j_adore: le_saucisson |
Merge from second level
In the example above, entries were merged in respect to the scope order of precedence. However, if we define the planets key forsa1, it will completely override the default value since the merge process is done at only 1 level.
You can add another level by passing ContextualizerInterface::MERGE_FROM_SECOND_LEVEL as an option (3rd argument) to$contextualizer->mapConfigArray().
| Code Block |
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| language | bash |
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| title | default_settings.yml |
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parameters:
acme_demo.default.foo_setting:
foo: ~
some: ~
planets: [Earth]
an_integer: 0
enabled: false
j_adore: [les_sushis] |
| Code Block |
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| language | bash |
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| title | Semantic config (ezplatform.yml / config.yml) |
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acme_demo:
system:
sa_group:
foo_setting:
foo: bar
some: thing
planets: [Mars, Venus]
an_integer: 123
# Assuming "sa1" is part of "sa_group"
sa1:
foo_setting:
an_integer: 456
enabled: true
j_adore: [le_saucisson, la_truite_a_la_vapeur] |
Result of using ContextualizerInterface::MERGE_FROM_SECOND_LEVEL option:
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parameters:
acme_demo.sa1.foo_setting:
foo: bar
some: thing
planets: [Earth, Mars, Venus]
an_integer: 456
enabled: true
j_adore: [les_suhis, le_saucisson, la_truite_a_la_vapeur] |
| Info |
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There is also another option, ContextualizerInterface::UNIQUE, to be used when you want to ensure your array setting has unique values. It will only work on normal arrays though, not hashes. |
Limitations
A few limitation exist with this scope hash merge:
- Semantic setting name and internal name will be the same (like
foo_setting in the examples above). - Applicable to first level semantic parameter only (i.e. settings right under the siteaccess name).
- Merge is not recursive. Only second level merge is possible by using
ContextualizerInterface::MERGE_FROM_SECOND_LEVEL option.
Dedicated mapper object
Instead of passing a callable to $processor->mapConfig(), an instance of eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\ConfigurationMapperInterface can be passed.
This can be useful if you have a lot of configuration to map and don't want to pollute your DIC extension class (better for maintenance).
Merging hash values between scopes
As specified above, $contextualizer->mapConfigArray() is not to be used within the scope loop, like for simple values. When using a closure/callable, you usually call it before or after $processor->mapConfig(). For mapper objects, a dedicated interface can be used: HookableConfigurationMapperInterface, which defines 2 methods: preMap() and postMap().