Interface yii\web\IdentityInterface

IdentityInterface is the interface that should be implemented by a class providing identity information.

This interface can typically be implemented by a user model class. For example, the following code shows how to implement this interface by a User ActiveRecord class:

class User extends ActiveRecord implements IdentityInterface
{
    public static function findIdentity($id)
    {
        return static::findOne($id);
    }

    public static function findIdentityByAccessToken($token, $type = null)
    {
        return static::findOne(['access_token' => $token]);
    }

    public function getId()
    {
        return $this->id;
    }

    public function getAuthKey()
    {
        return $this->authKey;
    }

    public function validateAuthKey($authKey)
    {
        return $this->authKey === $authKey;
    }
}

In some situations not all of these methods are required to be implemented. For example, if your application is a pure stateless RESTful application, you would only need to implement findIdentityByAccessToken() and getId() while leaving all other methods with an empty body. Or if your application uses session only authentication, you would need to implement all the methods except findIdentityByAccessToken().