README

Clean Symfony2 dependency injection for your Propel models

Installation

This bundle depends on GlorpenPropelBundle. Install that one first.

Require c33s/propel-di-behavior-bundle in your composer.json file:

{
    "require": {
        "c33s/propel-di-behavior-bundle": "@stable",
    }
}

Add propel behaviors to your propel config:

# app/config/config.yml

propel:
    # ...
    
    behaviors:
        c33s_di:        vendor.c33s.propel-di-behavior-bundle.src.C33sPropelDependencyCollectorBehavior
        
        # Optional: add another "instance" for global usage that does not interfere with model-specific behavior instances
        c33s_di_global: vendor.c33s.propel-di-behavior-bundle.src.C33sPropelDependencyCollectorBehavior

Register the bundle in app/AppKernel.php:

    // app/AppKernel.php

    public function registerBundles()
    {
        return array(
            // ...

            new C33s\PropelDIBehaviorBundle\C33sPropelDIBehaviorBundle(),
        );
    }

Usage

Add behavior to your propel models - either globally (use the c33s_di_global name for that) or to a specific model. You may inject Symfony2 services or parameters into any Model or Query class. Each definition consists of the service or parameter name to inject (enclose parameters in %-chars) followed by optional getter methods and type hints for this methods, separated by colons:

• logger:getLogger:\Psr\Log\LoggerInterface injects the Symfony2 logger service, making it accessible by $model->getLogger() (or $query->getLogger()) and providing \Psr\Log\LoggerInterface as a type hint for that getter
• logger injects the Symfony2 logger service without an explicit getter. Use $model->getInjectedDependency('logger') to access it.
• %locale%:getLocale:string injects the locale parameter, providing a getLocale() method for accessing it.

Example schema

<!-- my/Bundle/Resources/config/schema.xml -->

    <!-- this will inject the logger into ALL Propel model and query instances -->
    <behavior name="c33s_di_global">
        <parameter name="model" value="logger:getLogger:\Psr\Log\LoggerInterface" />
        <parameter name="query" value="logger:getLogger:\Psr\Log\LoggerInterface" />
    </behavior>

    <table name="book">
        <!-- this will inject the mailer and session into the Book instances and request_stack into BookQuery instances -->
        <behavior name="c33s_di">
            <parameter name="model" value="
                mailer:getMailer:\Swift_Mailer,
                session:getSession:\Symfony\Component\HttpFoundation\Session\Session,
            " />
            <parameter name="query" value="request_stack:getRequestStack:\Symfony\Component\HttpFoundation\RequestStack" />
        </behavior>
        
        <...>
    </table>

How it works

C33sPropelDIBehaviorBundle registers event listeners for model.create and query.create that are processed by GlorpenPropelBundle. Upon each model or query creation anonymous callbacks for each service will be injected into the classes, making sure that only the services that were specified in the schema can be accessed. The callback furthermore ensures that no services will be instantiated without actually being used.

So far this is the cleanest way I have found to inject specific Symfony2 dependencies into Propel models without messing around with the full DI container.