Symfony2 Config Component: Config Definition and Processing

Posted on May 12, 2012 by Matthias Noback

My previous post was about finding and loading configuration files. I now continue my Symfony2 Config Component quest with a post about the way you can “semantically expose your configuration” (using the TreeBuilder). I wrote this piece to later contribute it to the Symfony documentation so feedback is very welcome!

Validate configuration values

After loading configuration values from all kinds of resources, the values and their structure can be validated using the Definition part of the Symfony2 Config Component. Configuration values are usually expected to show some kind of hierarchy. Also, values should be of a certain type, be restricted in number or be one of a given set of values. For example, the following configuration (in Yaml) shows a clear hierarchy and some validation rules that should be applied to it (like: “the value for ‘auto_connect’ must be a boolean”):

Posted in Configuration, Symfony2, Validation | Leave a comment

Symfony2 Config Component: Using FileLocator, Loaders and LoaderResolver

Posted on May 3, 2012 by Matthias Noback

The Symfony2 Config Component provides several classes to help you find, load, combine, autofill and validate configuration values of any kind, whatever their source may be (Yaml, XML, INI files, or for instance a database).

Locating resources

Loading the configuration normally starts with a search for resources – in most cases: files. This can be done with FileLocator:

use Symfony\Component\Config\FileLocator;

$configDirectories = array(__DIR__ . DIRECTORY_SEPARATOR . 'app' . DIRECTORY_SEPARATOR . 'config');

$locator = new FileLocator($configDirectories);
$yamlUserFiles = $locator->locate('users.yml', null, false);

The locator receives a collection of locations where it should look for files. The first argument of locate() is the name of the file to look for. The second argument may be the current path and when supplied, the locator will look in this directory first.
The third argument indicates whether or not the locator should return the first file it has found, or an array containing all matches.

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Symfony2 & JMSSerializerBundle: Vendor MIME types and API versioning

Posted on April 26, 2012 by Matthias Noback

The JMSSerializerBundle has a VersionExclusionStrategy, which allows you to serialize/deserialize objects for a specific version of your API. You can mark the properties that are available for different versions using the @Since and @Until annotations:

use JMS\SerializerBundle\Annotation\Type;
use JMS\SerializerBundle\Annotation\Since;
use JMS\SerializerBundle\Annotation\Until;

class Comment
{
    /**
     * @Type("DateTime")
     * @Since("1.2.0")
     */
    private $createdAt;

    /**
     * @Type("DateTime")
     * @Until("2.1.3")
     */
    private $updatedAt;
}

The only thing you have to do is tell the serializer which version to use, before you start using it:

$this->get('serializer')->setVersion('2.0.2');

Posted in Annotation, Events, Request, Serializer, Service, Symfony2 | 1 Comment

PHP: A Custom Stream Wrapper Part 2: Reading and Seeking

Posted on April 22, 2012 by admin

In my previous post about the experimental DOM stream wrapper, I discussed the issues that came forth when opening the stream. Now, let’s take a look at another very important thing you want to do with a stream: read from and to it, and maybe move the pointer back and forth.

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PHP & Symfony