Symfony 3 Object of class could not be converted to string

Question

I'm have this address form. Everything is working as expected, until I added a drop down selection field for the cities. I'm getting this error when I try to save the form:

Catchable Fatal Error: Object of class AppBundle\Entity\Address could not be converted to string

The docs say that the EntityType field is designed to load options from a Doctrine entity.

This is the form:

 $builder
             ->add('cities', EntityType::class, array(
                'class' => \AppBundle\Entity\Cities::class,
                'choice_label' => 'cityname',
                'choice_value' => 'cityid')
            )

And this is my entity

 /**
 * @var string
 * 
 * @ORM\Column(name="cities", type="string", length=55, nullable=false)
 */
private $cities;   

And setters/getters:

 /**
 * Set cities
 *
 * @param string $cities
 *
 * @return Address
 */
public function setCities($cities)
{
    $this->cities = $cities;

    return $this;
}

/**
 * Get cities
 *
 * @return string
 */
public function getCities()
{
    return $this->cities;
}

I also added this:

public function __toString() {
  return $this->getCities();
}

And had this result:

Catchable Fatal Error: Method AppBundle\Entity\Address::__toString() must return a string value

Answer 1

You should implement __toString() method for you Entity:

__toString() allows a class to decide how it will react when it is treated like a string. For example, what echo $obj; will print. This method must return a string, as otherwise a fatal E_RECOVERABLE_ERROR level error is emitted.

For example, you could write something like this to represent your class as a string:

public function __toString() {
  return $this->getCities();
}

More info about this magic method here.