class Sport {
    /**
    * Bidirectional - Many facilies are related to one sport
    *
    * @ORMOneToMany(targetEntity="SportsFacility", mappedBy="sport")
    */
    protected $facilities;
    public function getFacilities() {
        return $this->facilities;
    }

    public function setFacilities($facilities) {
        $this->facilities = $facilities;
        return $this;
    }
}

class Facility {
    /**
    * Bidirectional - Many sports are related to one facility
    *
    * @ORMOneToMany(targetEntity="SportsFacility", mappedBy="facility")
    */
    protected $sports;
    public function getSports() {
        return $this->sports;
    }

    public function setSports($sportsFacilities) {
        $this->sports = $sportsFacilities;
        return $this;
    }

    public function addSports($sportsFacilities) {
        $this->sports = $sportsFacilities;
        return $this;
    }
}

class SportsFacility {
    /**
     * @var integer $sportsFacilityId
     *
     * @ORMColumn(name="sportsFacilityId", type="integer", nullable=false)
     * @ORMId
     * @ORMGeneratedValue(strategy="AUTO")
     */
    protected $sportsFacilityId;

    /**
    * Bidirectional - Many Sports are related to one Facility (OWNING SIDE)
    *
    * @ORMManyToOne(targetEntity="Sport", inversedBy="facilities"))
    * @ORMJoinColumn(name="sportId", referencedColumnName="sportId"))

    */
    protected $sport;
    /**
    * Bidirectional - Many Facilities are related to one Sport (OWNING SIDE)
    *
    * @ORMManyToOne(targetEntity="Facility", inversedBy="sports"))
    * @ORMJoinColumn(name="facilityId", referencedColumnName="facilityId"))
    */
    protected $facility;

    public function getSportsFacilityId() {
        return $this->sportsFacilityId;
    }

    public function setSportsFacilityId($sportsFacilityId) {
        $this->sportsFacilityId = $sportsFacilityId;
        return $this;
    }

    public function getSport() {
        return $this->sport;
    }

    public function setSport($sport) {
        $this->sport = $sport;
        return $this;
    }

    public function getFacility() {
        return $this->facility;
    }

    public function setFacility($facility) {
        $this->facility = $facility;
        return $this;
    }
}

protected function configureFormFields(FormMapper $formMapper)
{
    $formMapper
        ->add('name')
        ->with('Sports')
            ->add('sports', 'sonata_type_collection',
                array('by_reference' => false),
                array(
                    'edit' => 'inline',
                    'inline' => 'table',
                ))
        ->end();
}