User.php

<?php

namespace AppBundle\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Criteria;

/**
 * This assumes you already have a User entity, this just shows the parts
 * required
 */
class User
{
    /**
     * @var ArrayCollection
     * @ORM\OneToMany(targetEntity="UserSetting", mappedBy="user", fetch="EAGER", cascade={"all"})
     */
    protected $settings;

    /**
     * @return ArrayCollection
     */
    public function getSettings()
    {
        return $this->settings;
    }

    /**
     * Returns a UserSetting
     *
     * @param string $key
     * @return UserSetting
     */
    public function getSetting($key)
    {
        $criteria = Criteria::create()->where(Criteria::exper()-eq('key', $key));
        $setting  = $this->settings->matching($criteria)->first();

        if (false === $setting) {
            $setting = new UserSetting();
            $setting->setUser($this);
            $setting->setKey($key);
        }

        return $setting;
    }
    
    /**
     * @param string $key
     * @return boolean
     */
    public function hasSetting($key)
    {
        $criteria = Criteria::create()->where(Criteria::expr()->eq('key', $key));
        
        if ($this->settings->matching($criteria)->first()) {
            return true;
        }
        
        return false;
    }
    
    /**
     * This will either add the setting, or if a setting
     * with the same key is found, it will update that setting
     * 
     * @param UserSetting $setting
     */
    public function addSetting(UserSetting $setting)
    {
        if (false === $this->hasSetting($setting->getKey())) {
            $setting->setUser($this);
            $this->settings->add($setting);
            
            return;
        }
        
        $this->getSetting($setting->getKey())->setValue($setting->getValue());
    }
    
    public function removeSetting(UserSetting $setting)
    {
        if ($this->settings->contains($setting)) {
            $this->setting->removeElement($setting);
        }
    }
    
    /**
     * @param array $settings
     */
    public function setSettings($settings)
    {
        $this->settings = new ArrayCollection();
        foreach ($settings as $setting) {
            $this->addSetting($setting);
        }
    }
}