Dynamic settings injection

Description

Before 5.4, if one wanted to implement a service needing siteaccess-aware settings (e.g. language settings), they needed to inject the whole ConfigResolver (ezpublish.config.resolver) and get the needed settings from it.

This was not very convenient nor explicit. Goal of this feature is to allow developers to inject these dynamic settings explicitly from their service definition (yml, xml, annotation...).

Usage

Syntax

Static container parameters follows the %<parameter_name>% syntax in Symfony.

Dynamic parameters have the following: $<parameter_name>[; <namespace>[; <scope>]]$, default namespace being ezsettings, and default scope being current siteaccess.

For more information, see ConfigResolver documentation.

DynamicSettingParser

This feature also introduces a DynamicSettingParser service that can be used for adding support of the dynamic settings syntax. This service has ezpublish.config.dynamic_setting.parser for ID and implements eZ\Bundle\EzPublishCoreBundle\DependencyInjection\Configuration\SiteAccessAware\DynamicSettingParserInterface.

Limitations

A few limitations still remain:

• It is not possible to use dynamic settings in your semantic configuration (e.g. config.yml or ezpublish.yml) as they are meant primarily for parameter injection in services.
• It is not possible to define an array of options having dynamic settings. They will not be parsed. Workaround is to use separate arguments/setters.
• Injecting dynamic settings in request listeners is not recommended, as it won't be resolved with the correct scope (request listeners are instantiated before SiteAccess match). Workaround is to inject the ConfigResolver instead, and resolving the your setting in your onKernelRequest method (or equivalent).

Example

Injecting an eZ parameter

Defining a simple service needing languages parameter (i.e. prioritized languages).

Note: Internally, languages parameter is defined as ezsettings.<siteaccess_name>.languages, ezsettings being eZ internal namespace.

Before

parameters:
    acme_test.my_service.class: Acme\TestBundle\MyServiceClass

services:
    acme_test.my_service:
        class: %acme_test.my_service.class%
        arguments: [[@ezpublish](https://github.com/ezpublish).config.resolver]

namespace Acme\TestBundle;

use eZ\Publish\Core\MVC\ConfigResolverInterface;

class MyServiceClass
{
    /**
     * Prioritized languages
     *
     * [@var](https://github.com/var) array
     */
    private $languages;

    public function __construct( ConfigResolverInterface $configResolver )
    {
        $this->languages = $configResolver->getParameter( 'languages' );
    }
}

After, with setter injection (preferred)

parameters:
    acme_test.my_service.class: Acme\TestBundle\MyServiceClass

services:
    acme_test.my_service:
        class: %acme_test.my_service.class%
        calls:
            - [setLanguages, ["$languages$"]]

namespace Acme\TestBundle;

class MyServiceClass
{
    /**
     * Prioritized languages
     *
     * [@var](https://github.com/var) array
     */
    private $languages;

    public function setLanguages( array $languages = null )
    {
        $this->languages = $languages;
    }
}

Important: Ensure you always add null as a default value, especially if the argument is type-hinted.

After, with constructor injection

parameters:
    acme_test.my_service.class: Acme\TestBundle\MyServiceClass

services:
    acme_test.my_service:
        class: %acme_test.my_service.class%
        arguments: ["$languages$"]

namespace Acme\TestBundle;

class MyServiceClass
{
    /**
     * Prioritized languages
     *
     * [@var](https://github.com/var) array
     */
    private $languages;

    public function __construct( array $languages )
    {
        $this->languages = $languages;
    }
}

Tip: Setter injection for dynamic settings should always be preferred, as it makes it possible to update your services that depend on them when ConfigResolver is updating its scope (e.g. when previewing content in a given SiteAccess). Constructor injection will make your service be reset in that case.

However, only one dynamic setting should be injected by setter.

Injecting 3rd party parameters

parameters:
    acme_test.my_service.class: Acme\TestBundle\MyServiceClass

    # "acme" is our parameter namespace.
    # Null is the default value.
    acme.default.some_parameter: ~
    acme.ezdemo_site.some_parameter: foo
    acme.ezdemo_site_admin.some_parameter: bar

services:
    acme_test.my_service:
        class: %acme_test.my_service.class%
        # The following argument will automatically resolve to the right value, depending on the current SiteAccess.
        # We specify "acme" as the namespace we want to use for parameter resolving.
        calls:
            - [setSomeParameter, ["$some_parameter;acme$"]]

namespace Acme\TestBundle;

class MyServiceClass
{
    private $myParameter;

    public function setSomeParameter( $myParameter = null )
    {
        // Will be "foo" for ezdemo_site, "bar" for ezdemo_site_admin, or null if another SiteAccess.
        $this->myParameter = $myParameter;
    }
}