Question

Would be possible to check if an association exists before issuing a query in Doctrine2? Example:

/**
 * @ORM\Entity
 */
class Product
{
    /**
     * @ORM\OneToMany(targetEntity="Feature", inversedBy="product")
     */
    public $features;
}

I’d like to check (actually without issuing the query itself) it the association product.features exists.

EDIT: Out of curiosity i’m writing a service (an helper, really) to do some collection filtering based on GET paramters:

public function initialize($entityName, $key)
{
    // Defaults are empty values and empty collection
    $this->values     = array();
    $this->collection = new ArrayCollection();

    // If "$key" GET parameter is null or blank return this instance
    if(is_null($value = $this->request->get($key))
        || strlen(trim($value)) == 0) return $this;

    // Split the parameter value based on separator (typically a comma)
    $re = '/\s*' . $this->separator . '\s*/';

    // Return this instance if no values are found
    if(!($set = preg_split($re, $value, 0, PREG_SPLIT_NO_EMPTY))) return $this;

    // Guess the repository fully qualified name and entity name
    $guesser    = $this->getManagementGuesser();
    $repoName   = $guesser->guessRepositoryName();
    $entityName = $guesser->guessEntityName();

    // Get the repository for the entity and create the builder
    $qb = $this->getRepository($repoName)->createQueryBuilder('e');

    // Check if a relation named $key exists and throw a LogicException
    $exists = $this->getEntitiesUtility()->checkRelation($entityName, $key);
    if(!$exists) throw new \LogicException("Relation named '$key' not found.");

    // Other stuff
}

The relavant part would be:

$this->getEntitiesUtility()->checkRelation($entityName, $relationName);

Answer 1

// $em being your EntityManager..

if ($em->getClassMetadata($className)->getAssociationMapping($fieldName))
{
   ....
}