@ParamConverter
Usage
The @ParamConverter annotation calls converters to convert request
parameters to objects. These objects are stored as request attributes and so
they can be injected as controller method arguments:
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use Symfony\Component\Routing\Annotation\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
/**
 * @Route("/blog/{id}")
 * @ParamConverter("post", class="SensioBlogBundle:Post")
 */
public function show(Post $post)
{
}Several things happen under the hood:
- The converter tries to get a SensioBlogBundle:Postobject from the request attributes (request attributes comes from route placeholders -- hereid);
- If no Postobject is found, a404Response is generated;
- If a Postobject is found, a newpostrequest attribute is defined (accessible via$request->attributes->get('post'));
- As for other request attributes, it is automatically injected in the controller when present in the method signature.
If you use type hinting as in the example above, you can even omit the
@ParamConverter annotation:
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// automatic with method signature
public function show(Post $post)
{
}You can disable the auto-conversion of type-hinted method arguments feature
by setting the auto_convert flag to false:
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# config/packages/sensio_framework_extra.yaml
sensio_framework_extra:
    request:
        converters: true
        auto_convert: falseYou can also explicitly disable some converters by name:
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# config/packages/sensio_framework_extra.yaml
sensio_framework_extra:
    request:
        converters: true
        disable: ['doctrine.orm', 'datetime']To detect which converters are run on a parameter, the following process is run:
- If an explicit converter choice was made with
@ParamConverter(converter="name")the converter with the given name is chosen.
- Otherwise all registered parameter converters are iterated by priority. The
supports()method is invoked to check if a param converter can convert the request into the required parameter. If it returnstruethe param converter is invoked.
Built-in Converters
The bundle has two built-in converters, the Doctrine one and a DateTime converter.
Doctrine Converter
Converter Name: doctrine.orm
The Doctrine Converter attempts to convert request attributes to Doctrine entities fetched from the database. Several different approaches are possible:
1) Fetch Automatically
If your route wildcards match properties on your entity, then the converter will automatically fetch them:
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/**
 * Fetch via primary key because {id} is in the route.
 *
 * @Route("/blog/{id}")
 */
public function showByPk(Post $post)
{
}
/**
 * Perform a findOneBy() where the slug property matches {slug}.
 *
 * @Route("/blog/{slug}")
 */
public function show(Post $post)
{
}Automatic fetching works in these situations:
- If {id}is in your route, then this is used to fetch by primary key via thefind()method.
- The converter will attempt to do a findOneBy()fetch by using all of the wildcards in your route that are actually properties on your entity (non-properties are ignored).
You can control this behavior by actually adding the @ParamConverter
annotation and using the @ParamConverter options.
2) Fetch via an Expression
If automatic fetching doesn't work, use an expression:
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use Sensio\Bundle\FrameworkExtraBundle\Configuration\Entity;
/**
 * @Route("/blog/{post_id}")
 * @Entity("post", expr="repository.find(post_id)")
 */
public function show(Post $post)
{
}Use the special @Entity annotation with an expr option to
fetch the object by calling a method on your repository. The
repository method will be your entity's Repository class and
any route wildcards - like {post_id} are available as variables.
Tip
The @Entity annotation is a shortcut for using expr
and has all the same options as @ParamConverter.
This can also be used to help resolve multiple arguments:
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/**
 * @Route("/blog/{id}/comments/{comment_id}")
 * @Entity("comment", expr="repository.find(comment_id)")
 */
public function show(Post $post, Comment $comment)
{
}In the example above, the $post parameter is handled automatically, but $comment
is configured with the annotation since they cannot both follow the default convention.
DoctrineConverter Options
A number of options are available on the @ParamConverter or
(@Entity) annotation to control behavior:
- id: If an- idoption is configured and matches a route parameter, then the converter will find by the primary key:- 1 2 3 4 5 6 7 - /** * @Route("/blog/{post_id}") * @ParamConverter("post", options={"id" = "post_id"}) */ public function showPost(Post $post) { }
- mapping: Configures the properties and values to use with the- findOneBy()method: the key is the route placeholder name and the value is the Doctrine property name:- 1 2 3 4 5 6 7 8 - /** * @Route("/blog/{date}/{slug}/comments/{comment_slug}") * @ParamConverter("post", options={"mapping": {"date": "date", "slug": "slug"}}) * @ParamConverter("comment", options={"mapping": {"comment_slug": "slug"}}) */ public function showComment(Post $post, Comment $comment) { }
- excludeConfigures the properties that should be used in the- findOneBy()method by excluding one or more properties so that not all are used:- 1 2 3 4 5 6 7 - /** * @Route("/blog/{date}/{slug}") * @ParamConverter("post", options={"exclude": {"date"}}) */ public function show(Post $post, \DateTime $date) { }
- strip_nullIf true, then when- findOneBy()is used, any values that are- nullwill not be used for the query.
- entity_managerBy default, the Doctrine converter uses the default entity manager, but you can configure this:- 1 2 3 4 5 6 7 - /** * @Route("/blog/{id}") * @ParamConverter("post", options={"entity_manager" = "foo"}) */ public function show(Post $post) { }
- evict_cacheIf true, forces Doctrine to always fetch the entity from the database instead of cache.
DateTime Converter
Converter Name: datetime
The datetime converter converts any route or request attribute into a datetime instance:
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/**
 * @Route("/blog/archive/{start}/{end}")
 */
public function archive(\DateTime $start, \DateTime $end)
{
}By default, any date format that can be parsed by the DateTime constructor
or a unix timestamp is accepted. You can be stricter with input given through the options:
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/**
 * @Route("/blog/archive/{start}/{end}")
 * @ParamConverter("start", options={"format": "!Y-m-d"})
 * @ParamConverter("end", options={"format": "!Y-m-d"})
 */
public function archive(\DateTime $start, \DateTime $end)
{
}A date in a wrong format like 2017-21-22 will return a 404.
Creating a Converter
All converters must implement the ParamConverterInterface:
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namespace Sensio\Bundle\FrameworkExtraBundle\Request\ParamConverter;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
use Symfony\Component\HttpFoundation\Request;
interface ParamConverterInterface
{
    function apply(Request $request, ParamConverter $configuration);
    function supports(ParamConverter $configuration);
}The supports() method must return true when it is able to convert the
given configuration (a ParamConverter instance).
The ParamConverter instance has three pieces of information about the annotation:
- name: The attribute name;
- class: The attribute class name (can be any string representing a class name);
- options: An array of options.
The apply() method is called whenever a configuration is supported. Based
on the request attributes, it should set an attribute named
$configuration->getName(), which stores an object of class
$configuration->getClass().
If you're using service auto-registration and autoconfiguration, you're done! Your converter will automatically be used.
You can register a converter by priority, by name (attribute "converter"), or
both. If you don't specify a priority or a name, the converter will be added to
the converter stack with a priority of 0. To explicitly disable the
registration by priority you have to set priority="false" in your tag
definition.
Tip
If you would like to inject services or additional arguments into a custom
param converter, the priority shouldn't be higher than 1. Otherwise, the
service wouldn't be loaded.
Tip
Use the DoctrineParamConverter class as a template for your own converters.