Getting Started with the Discovery Component

The way you install and use the Discovery Component depends on the type of project you are working on:

  • In a Symfony Project, the Discovery Component is installed through Puli’s Symfony Bundle.
  • In a PHP Application that will never be a dependency of other Composer packages, the Discovery Component is installed through Puli’s Composer Plugin.
  • In a Composer Package that is a dependency of an application or other packages, the Discovery Component needs to be installed manually.

In a Symfony Project

Important

Before you continue, install the Puli CLI and the Repository Component in your project.

In a Symfony application, the Discovery Component is installed through Puli’s Symfony Bundle. If you followed Getting Started with the Repository Component, this bundle is already installed in your application.

As a resource consumer, you can define a new binding type with the type --define command of the Puli CLI:

$ php puli.phar type --define thor/translations

Note

The name of a binding type must always start with the vendor name of your Composer package. This prevents naming collisions and makes sure that you own the type.

The type --define command adds the new binding type to your puli.json.

Use Puli’s ResourceDiscovery to access all bindings bound to your binding type. Each ResourceBinding instance may refer to more than one Resource, for example if the bound path contains the wildcard “*”. Consequently you need a double loop to access the resources in your code:

class PostController
{
    public function indexController()
    {
        $bindings = $this->get('puli.discovery')->findByType('thor/translations');

        foreach ($bindings as $binding) {
            foreach ($binding->getResources() as $resource) {
                echo $resource->getPath();
            }
        }
    }
}

As a resource provider, you can bind resources to a binding type with the bind command of the Puli CLI:

$ php puli.phar bind /app/trans/*.yml thor/translations

The bind command adds the new binding to your puli.json.

If a resource consumer and a resource provider are installed at the same time, Puli makes sure that the consumer receives all resources bound to its binding type by the provider.

In a PHP Application

Important

Before you continue, install the Puli CLI and the Repository Component in your project.

In a PHP application, the Discovery Component is installed through Puli’s Composer Plugin. If you followed Getting Started with the Repository Component, this bundle is already installed in your application.

As a resource consumer, you can define a new binding type with the type --define command of the Puli CLI:

$ php puli.phar type --define thor/translations

Note

The name of a binding type must always start with the vendor name of your Composer package. This prevents naming collisions and makes sure that you own the type.

The type --define command adds the new binding type to your puli.json.

With Puli’s ResourceDiscovery class you can access all bindings bound to your binding type. Use the Puli factory to create the ResourceDiscovery instance:

$factoryClass = PULI_FACTORY_CLASS;
$factory = new $factoryClass();

$repo = $factory->createRepository();
$discovery = $factory->createDiscovery($repo);

Note

For performance reasons, Puli services such as $factory or $repo should be created only once per application. Instead of storing them in global variables, it is usually nicer to use a Dependency Injection Container for creating the services on demand. A simple Dependency Injection Container for small projects is Pimple.

Each ResourceBinding instance may refer to more than one Resource, for example if the bound path contains the wildcard “*”. Consequently you need a double loop to access the resources in your code:

$bindings = $discovery->findByType('thor/translations');

foreach ($bindings as $binding) {
    foreach ($binding->getResources() as $resource) {
        echo $resource->getPath();
    }
}

As a resource provider, you can bind resources to a binding type with the bind command of the Puli CLI:

$ php puli.phar bind /app/trans/*.yml thor/translations

The bind command adds the new binding to your puli.json.

If a resource consumer and a resource provider are installed at the same time, Puli makes sure that the consumer receives all resources bound to its binding type by the provider.

In a Composer Package

Important

Before you continue, install the Puli CLI and the Repository Component in your project.

In a Composer package, the Discovery Component is installed manually. Before you install the component, set “minimum-stability” to “beta” in composer.json:

{
    "minimum-stability": "beta"
}

Install the component with Composer:

$ composer require puli/discovery:^1.0

As a resource consumer, you can define a new binding type with the type --define command of the Puli CLI:

$ php puli.phar type --define thor/translations

Note

The name of a binding type must always start with the vendor name of your Composer package. This prevents naming collisions and makes sure that you own the type.

The type --define command adds the new binding type to your puli.json.

With Puli’s ResourceDiscovery class you can access all bindings bound to your binding type. Each ResourceBinding instance may refer to more than one Resource, for example if the bound path contains the wildcard “*”. Consequently you need a double loop to access the resources in your code:

use Puli\Discovery\Api\ResourceDiscovery;

class TranslationLoader
{
    private $discovery;

    public function __construct(ResourceDiscovery $discovery)
    {
        $this->discovery = $discovery;
    }

    public function loadTranslations($catalog, $language)
    {
        $bindings = $this->discovery->findByType('thor/translations');
        $resourceName = $catalog.'.'.$language.'.yml';

        foreach ($bindings as $binding) {
            foreach ($binding->getResources() as $resource) {
                if ($resourceName === $resource->getName()) {
                    return Yaml::parse($resource->getBody());
                }
            }
        }

        return array();
    }
}

You should never create ResourceDiscovery instances in a Composer package. Instead, let the application that uses your package create the discovery and pass it to your code. This way, every part of the application uses the same instance and benefits of caching and other optimizations done internally.

As a resource provider, you can bind resources to a binding type with the bind command of the Puli CLI:

$ php puli.phar bind /batman/blog/trans/*.yml thor/translations

The bind command adds the new binding to your puli.json.

If a resource consumer and a resource provider are installed at the same time, Puli makes sure that the consumer receives all resources bound to its binding type by the provider.

Further Reading