calculated/virtual field in symfony entity - how to do it?

Question

I have first entity called "places" that maps places data like place name,latitude and longitude. Another entity called "users" stores the user data like username,user current latitude,user current longitude.

I want to add a virtual field for the "places" entity that calculate the distance between the geo points.

I'm using this function -

class Places{

/**
 * @var integer
 *
 * @ORM\Column(name="id", type="integer")
 * @ORM\Id
 * @ORM\GeneratedValue(strategy="AUTO")
 */
private $id;

/**
 * @var string
 * @ORM\Column(name="name", type="string", length=255)
 * @Assert\NotBlank()
 * @Expose
 */
private $name;

/**
 * @var string
 * @ORM\Column(name="description", type="string", length=255, nullable=true)
 * @Expose
 */
private $description;

/**
 * @var float
 * @ORM\Column(name="lon", type="float", nullable=true)
 * @Expose
 */
private $lon;

/**
 * @var float
 * @ORM\Column(name="lat", type="float", nullable=true)
 * @Expose
 */
private $lat;

/**
 * @var integer
 * @ORM\ManyToOne(targetEntity="Countries")
 * @ORM\JoinColumn(name="country", referencedColumnName="id", onDelete="SET NULL")
 * @Assert\NotBlank()
 * @Expose
 */
private $country;

/**
 * @var string
 * @VirtualProperty
 * @Type("string")
 * @SerializedName("distance")
 * @return string
 */
public function distance(){

    $longitude1 = '34.7722';//$user->getLon();(?)
    $latitude1 = '32.0114';//$user->getLat();(?)
    $longitude2 = $this->getLon();
    $latitude2  = $this->getLat();

    $theta = $longitude1 - $longitude2;
    $miles = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
    $miles = acos($miles);
    $miles = rad2deg($miles);
    $miles = $miles * 60 * 1.1515;
    $kilometers = $miles * 1.609344;
    //return round($kilometers);
    return $this->user->getLastName();
}
}

but as you can see the lon1/lat1 are hard coded because i can't get the user lan/lat from with in the places entity.

How do i do it?

Thanks.

Answer 1

You can pass $place entity to your function:

public function distance($place)
{
      $longitude1 = $place->getLon();
      $latitude1 = $place->getLat();
      $longitude2 = $this->getLon();
      $latitude2  = $this->getLat();

      $theta = $longitude1 - $longitude2;
      $miles = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
      $miles = acos($miles);
      $miles = rad2deg($miles);
      $miles = $miles * 60 * 1.1515;
      $kilometers = $miles * 1.609344;

      return round($kilometers);
}

Answer 2

you do not have any relations between place and user, you cant do that inside place entity. Assuming that user is the logged user. Your logic has to be in a service and inject TokenStorage to get the user logged:

namespace Acme\Bundle\AcmeBundle\Manager;

use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
use Acme\Bundle\AcmeBundle\Entity\Location;


class LocationFinder{
/*
 * @var TokenStorageInterface
 */
private $tokenStorage;

public function __construct(TokenStorageInterface $tokenStorage)
{
    $this->tokenStorage = $tokenStorage;
}

public function getDistance(Location $location)
{
    $longitude1 =$this->tokenStorage->getToken()->getUser()->getLon();
    $latitude1 = $this->tokenStorage->getToken()->getUser()->getLat();

    $longitude2 = $this->getLon();
    $latitude2  = $this->getLat();

    $theta = $longitude1 - $longitude2;
    $miles = (sin(deg2rad($latitude1)) * sin(deg2rad($latitude2))) + (cos(deg2rad($latitude1)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
    $miles = acos($miles);
    $miles = rad2deg($miles);
    $miles = $miles * 60 * 1.1515;
    $kilometers = $miles * 1.609344;
    return round($kilometers);

}

}

Then you have to create the service inside Resources\config\services.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

<services>
    <service id="acme.manager.location_finder" class="Acme\Bundle\AcmeBundle\Manager\LocationFinder">
        <argument type="service" id="security.token_storage" />
    </service>
</services>
</container>

now you can get the LocationService inside a controller and get the distance between place and the user logged

class AccountController extends Controller
{

/**
 * @Route("/place/{id}", name="place")
 * @Method("GET")
 */
public function placeAction($id)
{
    $em = $this->getDoctrine()->getEntityManager();
    $location = $em->getRepository('AcmeBundle:Location')->findOneBy([
        'id' => $id
    ]);
    $distance = $this->get('acme.manager.location_finder')->getDistance($location);
}

}

You have more information here: http://symfony.com/doc/current/book/service_container.html

Sf2 : using a service inside an entity

Answer 3

I got it!! Managed to solve this problem using an event listener .

listener:

class SearchIndexer{

        public function __construct(TokenStorageInterface  $tokenStorage)
        {
            $this->tokenStorage = $tokenStorage;
        }

        public function postLoad (LifecycleEventArgs $args){
            $entity = $args->getEntity();
            if ($entity instanceof Places) {
                $user = $this->tokenStorage->getToken()->getUser();
                $entity->setUser_longitude($user->getLastGeoLocationLon());
                $entity->setUser_latitude($user->getLastGeoLocationLat());
            }
        }

    }

services:

services:
   doctrine.listener:
      class: ApplicationBundle\Listener\SearchIndexer
      arguments: ["@security.token_storage"]
      tags:
          - { name: doctrine.event_listener, event: postLoad }

places entity:

class Places
{
  private $user_longitude;

        public function setUser_longitude($user_longitude){
            $this->user_longitude = $user_longitude;
        }

        private $user_latitude;

        public function setUser_latitude($user_latitude){
            $this->user_latitude = $user_latitude;
        }

        /**
         * @var string
         * @VirtualProperty
         * @Type("string")
         * @SerializedName("distance")
         * @return string
         */
        public function distance(){

            $longitude2 = $this->getLon();
            $latitude2  = $this->getLat();

            $theta = $this->user_longitude - $longitude2;
            $miles = (sin(deg2rad($this->user_latitude)) * sin(deg2rad($latitude2))) + (cos(deg2rad($this->user_latitude)) * cos(deg2rad($latitude2)) * cos(deg2rad($theta)));
            $miles = acos($miles);
            $miles = rad2deg($miles);
            $miles = $miles * 60 * 1.1515;
            $kilometers = $miles * 1.609344;
            return round($kilometers);

        }
 //rest of the class
}