Complete Example

In this example, we'll create a complete configuration subsystem for an imaginary application.

We assume that our application has the following directory structure:

example
│
└───app
│    └───config
│    │      example-config.yml
│    │
│    └───resources
│
└───src
│    └───Configuration
│            ExampleConfiguration.php
│
└───var
│    └───log
│    │
│    └───cache
│
│
└───tests

• app/config/example-config.yml is our configuration file
• var/cache is our cache directory
• src/Configuration/ExampleConfiguration.php is our definition class

The application namespace is App and it points to src directory.

We want to manage our configuration via Dot Access Data library.

Installation

We need to install:

• susina/config-builder (of course!)
• symfony/yaml since we decide to use yaml format for our file
• dflydev/dot-access-data we love to access the configuration properties via dot syntax

composer require susina/config-builder symfony/yaml dflydev/dot-access-data

Our configuration file

The configuration file, we'll load and process, is app/config/example-config.yaml:

app/config/example-config.yaml

app:
  database:
    auto_connect: true
    default_connection: pgsql
    connections:
      pgsql:
        host: localhost
        driver: postgresql
        username: user
        password: pass
      sqlite:
        host: localhost
        driver: sqlite
        memory: true
        username: user
        password: pass

  paths:
    template: app/resources
    logger: var/log

The definition class

The class containing the definition, to process the configuration parameters is App\Configuration\ExampleConfiguration.php:

App\Configuration\ExampleConfiguration.php

<?php declare(strict_types=1);

namespace App\Configuration;

use Symfony\Component\Config\Definition\Builder\NodeDefinition;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;
use Symfony\Component\Config\Definition\ConfigurationInterface;

class ExampleConfiguration implements ConfigurationInterface
{
    public function getConfigTreeBuilder()
    {
        $treeBuilder = new TreeBuilder('app');
        $treeBuilder->getRootNode()
            ->append($this->addDatabaseNode())
            ->append($this->addPathsNode())
        ;
    }

    public function addDatabaseNode(): NodeDefinition
    {
        $treeBuilder = new TreeBuilder('database');

        $treeBuilder->getRootNode()
            ->children()
                ->booleanNode('auto_connect')->defaultTrue()->end()
                ->scalarNode('default_connection')->defaultValue('default')->end()
                ->fixXmlConfig('connection')
                ->children()
                    ->arrayNode('connections')
                        ->arrayPrototype()
                            ->children()
                                ->scalarNode('driver')->end()
                                ->scalarNode('host')->end()
                                ->scalarNode('username')->end()
                                ->scalarNode('password')->end()
                            ->end()
                        ->end()
                    ->end()
                ->end()
            ->end()
        ;

        return $treeBuilder;
    }

    public function addPathsNode(): NodeDefinition
    {
        $treeBuilder = new TreeBuilder('paths');

        $treeBuilder->getRootNode()
            ->children()
                ->scalarNode('template')->required()->end()
                ->scalarNode('logger')->end()
            ->end()
        ;

        return $treeBuilder;
    }
}

Let's go

Let's use the ConfigurationBuilder to load and process our file and to instantiate the class, to manage the configuration:

<?php declare(strict_types=1);

use App\Configuration\ExampleConfiguration;
use Dflydev\DotAccessData\Data;


$config = ConfigurationBuilder::create()
    ->addDirectory('app/config')
    ->addFile('example-config.yml')
    ->setDefinition(ExampleConfiguration::class)
    ->setConfigurationClass(Data::class)
    ->setCacheDirectory('var/log')
    ->getConfiguration()
;

//Now we ca use our configuration object
$connection = new Connection(
    $config->get('database.user'),
    $config->get('database.pass')
);

$template = new Template();
$template->setDir($config->get('paths.template'));