puzzle/configuration

3.0.0 2017-03-10 15:11 UTC

README

Hide configuration implementation behind common interface.

Some advantages :

  • Application does not depend upon configuration implementation details
  • Application does not have to manage filesystem issues (for filesystem based implementations)
  • Application can be easily tested, even for configuration edge cases (missing or wrong configuration values)
  • Define configuration as a service in your dependency injection container

QA

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Installation

Use composer :

{
    "require": {
            "puzzle/configuration" : "~2.0"
    }
}

Documentation

Configuration as a service

<?php

class Example
{
    public function __construct(Puzzle\Configuration $config)
    {
        $threshold = $config->read('app/detection/threshold');
    }
}

The way the configuration value is read depends on the chosen implementation.

Up to now, 2 implementations are provided :

  • Memory (for unit testing purpose)
  • Yaml (based on Symfony/Yaml).

For YAML one, 'app/detection/threshold' means detection[thresold] in app.yml file. When you instanciate YamlConfiguration object, you need to provide where yaml files can be found :

<?php

$fileSystem = new Gaufrette\Filesystem(
    new Local('path/to/yaml/files/root/dir')
);
$config = new Puzzle\Configuration\Yaml($fileSystem);

$example = new Example($config);
# app.yml 

detection:
  threshold: 3

Unit testing

<?php

$config = new Puzzle\Configuration\Memory(array(
    'app/detection/threshold' => 2
);

$example = new ExampleTest($config);

Default values

<?php

$configuration->read('a/b/c', 'default value if a/b/c does not exist');

But if a/b/c is required :

<?php

// will throw an exception if a/b/c does not exist
$configuration->readRequired('a/b/c');

Fallback strategy

<?php

// Since 1.5.0
// returns value associated to first existing key
// will throw an exception if none exist
$configuration->readFirstExisting('a/b/c', 'd/e/f', 'x/y/z');

Override configuration

If you need some configuration to (partially or not) override another one :

<?php

// Since 1.6.0
$defaultFileSystem = new Gaufrette\Filesystem(
    new Local('path/to/yaml/files/root/dir')
);
$defaultConfig = new Puzzle\Configuration\Yaml($defaultFileSystem);

$fileSystem = new Gaufrette\Filesystem(
    new Local('path/to/another/config/files')
);
$localConfig = new Puzzle\Configuration\Yaml($fileSystem);

$config = new Puzzle\Configuration\Stacked();
$config->overrideBy($defaultConfig)
       ->overrideBy($localConfig);

// values will be read in localConfig first. They will be read in default config only if they don't exist in local one.

Another example :

<?php

$fileSystem = new Gaufrette\Filesystem(
    new Local('path/to/yaml/files/root/dir')
);
$defaultConfig = new Puzzle\Configuration\Yaml($fileSystem);

$overrideConfig = new Puzzle\Configuration\Memory(array(
    'app/detection/threshold' => 2
);

$config = new Puzzle\Configuration\Stacked();
$config->overrideBy($defaultConfig)
       ->overrideBy($overrideConfig);

You can add as many as configuration instances you want in the stack. The last inserted is the most prioritary.

If you want to add the least prioritary, use the addBase() method :

<?php

// Since 2.0.0
$config = new Puzzle\Configuration\Stacked();
$config->overrideBy($overrideConfig)
       ->addBase($defaultConfig);

Prefixed configuration

You can use automatic prefix decorator PrefixedConfiguration. It can be useful for "namespace like" configurations such as loggers or multiple databases ones.

# logger.yml 

app:
  filename: app.log
  verbosity: INFO
users:
  filename: users.log
  verbosity: WARNING
<?php

// Since 1.7.0
$fileSystem = new Gaufrette\Filesystem(
    new Local('path/to/yaml/files/root/dir')
);
$config = new Puzzle\Configuration\Yaml($fileSystem);
$config = new Puzzle\PrefixedConfiguration($config, "logger/$loggerName");

$filename = $config->readRequired('filename');
$verbosity = $config->readRequired('verbosity');

Changelog

2.x --> 3.x

  • Drop php 5.5 support. Minimal version is 5.6.0

1.x -> 2.x

  • Drop php 5.4 support. Minimal version is 5.5.0