Fluent configuration for Symfony

This package offers an alternative configuration syntax for Symfony's container, inspired by PHP-DI's configuration.

• Why?
• Comparison with existing formats
• Installation
• Syntax
• Parameters
• Services
  • Using the class name as the entry ID
  • Autowiring
  • Constructor arguments
  • Dependencies
  • Setter injection
  • Property injection
  • Optional service references
  • Decorated services
  • Non shared services
• Factories
• Aliases
• Tags
• Imports
• Extensions

Why?

The main goal is to benefit from stricter analysis from the PHP engine and IDEs. If you are interested you can also read why YAML was replaced by a similar syntax in PHP-DI 5.

• auto-completion on classes or constants:

  

• auto-completion when writing configuration:

  

• real time validation in IDEs:

  

• constant support:

  

• better refactoring support

Comparison with existing formats

Currently, in Symfony, you can configure the container using:

• YAML

  parameters:
      mailer.transport: sendmail
  
  services:
      mailer:
          class:     Mailer
          arguments: ['%mailer.transport%']

• XML

  <?xml version="1.0" encoding="UTF-8" ?>
  <container xmlns="http://symfony.com/schema/dic/services"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
  
      <parameters>
          <parameter key="mailer.transport">sendmail</parameter>
      </parameters>
  
      <services>
          <service id="mailer" class="Mailer">
              <argument>%mailer.transport%</argument>
          </service>
      </services>
  </container>

• PHP code

  $container->setParameter('mailer.transport', 'sendmail');
  $container
      ->register('mailer', 'Mailer')
      ->addArgument('%mailer.transport%');

With this package, you can now use a 4th alternative:

return [
    'mailer.transport' => 'sendmail',

    'mailer' => create(Mailer::class)
        ->arguments('%mailer.transport%'),
];

Installation

composer require mnapoli/fluent-symfony

To enable the new format in a Symfony fullstack application, simply import the EnableFluentConfig trait in app/AppKernel.php, for example:

<?php

use Fluent\EnableFluentConfig;
use Symfony\Component\HttpKernel\Kernel;
// ...

class AppKernel extends Kernel
{
    use EnableFluentConfig;

    // ...
}

You can now either:

• write all your config in "fluent" syntax, to do that change your AppKernel to load .php files instead of .yml:

  class AppKernel extends Kernel
  {
      use EnableFluentConfig;
  
      // ...
  
      public function registerContainerConfiguration(LoaderInterface $loader)
      {
          $loader->load($this->getRootDir().'/config/config_'.$this->getEnvironment().'.php');
      }
  }

• or import PHP config files from YAML config files:

  imports:
      - services.php
      
  # ...

Be advised that PHP config files in the "traditional" form (see the documentation) are still supported and will continue to work.

Syntax

A configuration file must return a PHP array. In that array, parameters, services and imports are defined altogether:

<?php
# app/config/config.php

return [
    // ...
];

Parameters

Parameters are declared as simple values:

return [
    'foo' => 'bar',
];

This is the same as:

parameters:
    foo: 'bar'

Parameters and services can be mixed in the same array.

Services

Services can be declared simply using the create() function helper:

use function Fluent\create;

return [
    'mailer' => create(Mailer::class),
];

When calling $container->get('mailer') an instance of the Mailer class will be created and returned.

This is the same as:

services:
    mailer:
        class: Mailer

Using the class name as the entry ID

If the container entry ID is a class name, you can skip it when calling create().

return [
    Mailer::class => create(),
];

Autowiring

Services can also be automatically wired using the autowire() function helper in place of create():

use function Fluent\autowire;
 
return [
    Mailer::class => autowire(),
];

This is the same as:

services:
    Mailer:
        class: Mailer
        autowire: true

Constructor arguments

return [
    'mailer' => create(Mailer::class)
        ->arguments('smtp.google.com', 2525),
];

This is the same as:

services:
    mailer:
        class: Mailer
        arguments: ['smtp.google.com', 2525]

Dependencies

Parameters can be injected using the '%foo%' syntax:

return [
    'mailer' => create(Mailer::class)
        ->arguments('%mailer.transport%'),
];

This is the same as:

services:
    mailer:
        class:     Mailer
        arguments: ['%mailer.transport%']

Services can be injected using the get() function helper:

use function Fluent\get;

return [
    'newsletter_manager' => create(NewsletterManager::class)
        ->arguments(get('mailer')),
];

This is the same as:

services:
    newsletter_manager:
        class: NewsletterManager
        arguments: ['@mailer']

Setter injection

return [
    'mailer' => create(Mailer::class)
        ->method('setHostAndPort', 'smtp.google.com', 2525),
];

This is the same as:

services:
    mailer:
        class: Mailer
        calls:
            - [setHostAndPort, ['smtp.google.com', 2525]]

Property injection

return [
    'mailer' => create(Mailer::class)
        ->property('host', 'smtp.google.com'),
];

This is the same as:

services:
    mailer:
        class: Mailer
        properties:
            host: smtp.google.com

Optional service references

Services can have optional dependencies, so that the dependency is not required for it to work.

Setting missing dependencies to null

use function Fluent\create;
use function Fluent\get;

return [
    'newsletter_manager' => create(NewsletterManager::class)
        ->arguments(get('mailer')->nullIfMissing()),
];

This is the same as :

<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>
        <service id="newsletter_manager" class="NewsletterManager">
            <argument type="service" id="mailer" on-invalid="null" />
        </service>
    </services>
</container>

Ignore missing dependencies

When used with setter injection, it's possible to remove the method call using ignoreIfMissing() :

use function Fluent\create;
use function Fluent\get;

return [
    'newsletter_manager' => create(NewsletterManager::class)
        ->method('setMailer', get('mailer')->ignoreIfMissing()),
];

This is the same as :

services:
    app.newsletter_manager:
        class:     AppBundle\Newsletter\NewsletterManager
        calls:
            - [setMailer, ['@?app.mailer']]

Private Services

return [
    Mailer::class => create()
        ->private(),
];

This is the same as:

services:
    mailer:
        class: Mailer
        public: false

Decorated services

Services can be decorated with the decorate() method

return [
    'decorating_mailer' => create(MailerDecorator::class)
        ->decorate('mailer')
        ->argument(get('decorating_mailer.inner')),
];

This is the same as:

services:
    decorating_mailer:
        class: 'MailerDecorator'
        decorates: 'mailer'
        arguments: ['@decorating_mailer.inner']

If you want to apply more than one decorator to a service, you can change the inner service name (IE the decorated service) and configure the priority of decoration :

return [
    'foo' => create(Foo::class),
    'bar' => create(Bar::class)
        ->decorate('foo', 'bar.foo', 5)
        ->arguments(get('bar.foo'))
    ,
    'baz': create(Baz::class)
        ->decorate('foo', 'baz.foo', 1),
        ->arguments(get('baz.foo'))
];

This is the same as:

foo:
    class: Foo

bar:
    class: Bar
    decorates: foo
    decoration_inner_name: 'bar.foo'
    decoration_priority: 5
    arguments: ['@bar.foo']

baz:
    class: Baz
    decorates: foo
    decoration_inner_name: 'baz.foo'
    decoration_priority: 1
    arguments: ['@baz.inner']

Non shared services

All services are shared by default. You can force the container to always create a new instance using the unshared() function helper:

return [
    'app.phpmailer' => create(PhpMailer::class)
        ->unshared(),
];

This is the same as:

services:
    app.phpmailer:
        class: AppBundle\Mail\PhpMailer
        shared: false

Synthetic services

Services can be injected at runtime. You can inject a class instance as service, instead of configuring the container to create a new instance using the synthetic() function helper:

return [
    'app.phpmailer' => create(PhpMailer::class)
        ->synthetic(),
];

This is the same as:

services:
    app.phpmailer:
        class: AppBundle\Mail\PhpMailer
        synthetic: true

Factories

Services can be created by factories using the factory() function helper:

use function Fluent\factory;

return [
    'newsletter_manager' => factory([NewsletterManager::class, 'create'], NewsletterManager::class)
        ->arguments('foo', 'bar'),
];

When calling $container->get('newsletter_manager') the result of NewsletterManager::create('foo', 'bar') will be returned.

This is the same as:

services:
    newsletter_manager:
        factory: ['AppBundle\Email\NewsletterManager', 'create']
        class: 'AppBundle\Email\NewsletterManager'
        arguments: ['foo', 'bar']

When using the class name as service ID, you don't have to explicitly state the class name of the service:

return [
    // you can write:
    NewsletterManager::class => factory([NewsletterManager::class, 'create']),
    // instead of:
    NewsletterManager::class => factory([NewsletterManager::class, 'create'], NewsletterManager::class),
];

Aliases

Services can be aliased using the alias() function helper:

use function Fluent\create;
use function Fluent\alias;

return [
    'app.phpmailer' => create(PhpMailer::class),
    'app.mailer' => alias('app.phpmailer'),
];

When calling $container->get('app.mailer') the app.phpmailer entry will be returned.

This is the same as:

services:
    app.phpmailer:
        class: AppBundle\Mail\PhpMailer
    app.mailer:
        alias: app.phpmailer

Private Aliases

return [
    'app.phpmailer' => create(PhpMailer::class),
    'app.mailer' => alias('app.phpmailer')
        ->private(),
];

This is the same as:

services:
    app.phpmailer:
        class: AppBundle\Mail\PhpMailer
    app.mailer:
        alias: app.phpmailer
        public: false

Tags

Services can be tagged :

return [
    'mailer' => create(Mailer::class)
        ->tag('foo', ['fizz' => 'buzz', 'bar' => 'baz'])
        ->tag('bar'),
];

This is the same as:

services:
    mailer:
        class: Mailer
        tags:
            - {name: foo, fizz: buzz, bar: baz}
            - {name: bar}

Imports

Other configuration files can be imported using the import() function helper:

use function Fluent\import;

return [
    import('services/mailer.php'),
];

You will notice that the array item is not indexed by an entry ID.

This is the same as:

imports:
    - { resource: services/mailer.yml }

Extensions

Extensions (like the framework configuration for example) can be configured using the extension() function helper:

use function Fluent\extension;

return [
    extension('framework', [
        'http_method_override' => true,
        'trusted_proxies' => ['192.0.0.1', '10.0.0.0/8'],
    ]),
];

This is the same as:

framework:
    http_method_override: true
    trusted_proxies: [192.0.0.1, 10.0.0.0/8]