Timezone.php

<?php

namespace Lunetics\TimezoneBundle\Validator;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class Timezone extends Constraint
{
    public $message = 'The timezone "%string%" is not a valid timezone';
}

TimezoneValidator.php

<?php
/**
 * This file is part of the MfCoreBundle package.
 *
 * <https://github.com/lunetics/>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that is distributed with this source code.
 */
namespace Lunetics\TimezoneBundle\Validator;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

/**
 * Timezone Validator Class
 *
 * @author Matthias Breddin <[email protected]>
 */
class TimezoneValidator extends ConstraintValidator
{

    /**
     * Validates the Timezone
     *
     * @param string               $timezone   The timezone string
     * @param Timezone|Constraint  $constraint timezone Constraint
     */
    public function validate($timezone, Constraint $constraint)
    {
        if (!in_array($timezone, \DateTimeZone::listIdentifiers())) {
            $this->context->addViolation($constraint->message, array('%string%' => $timezone));
        }
    }
}

TimezoneValidatorTest.php

<?php

namespace Lunetics\TimezoneBundle\Tests\Validator;

use Lunetics\TimezoneBundle\Validator\Timezone;
use Lunetics\TimezoneBundle\Validator\TimezoneValidator;

/**
 * Test for the Timezone Validator
 */
class TimezoneValidatorTest extends \PHPUnit_Framework_TestCase
{
    protected $context;

    /**
     * Setup
     */
    public function setUp()
    {
        $this->context = $this->getContext();
    }

    /**
     * Provider for Valid Timezones
     *
     * @return array
     */
    public function validTimezones()
    {
        return array(
            array('Europe/Berlin'),
            array('UTC'),
            array('America/New_York')
        );
    }

    /**
     * Test if Timezone is valid
     *
     * @param string $timezone
     *
     * @dataProvider validTimezones
     */
    public function testTimezoneIsValid($timezone)
    {
        $constraint = new Timezone();
        $this->context->expects($this->never())
                ->method('addViolation');
        $this->getTimezoneValidator()->validate($timezone, $constraint);
    }

    /**
     * Provider for Invalid Timezones
     *
     * @return array
     */
    public function invalidTimezones()
    {
        return array(
            array('GMT'),
            array('NONE'),
            array('EST')
        );
    }

    /**
     * Test if Timezone is invalid
     *
     * @param string $timezone
     *
     * @dataProvider invalidTimezones
     */
    public function testTimezoneIsInvalid($timezone)
    {
        $constraint = new Timezone();
        $this->context->expects($this->once())
                ->method('addViolation')
                ->with($this->equalTo($constraint->message), $this->equalTo(array('%string%' => $timezone)));
        $this->getTimezoneValidator()->validate($timezone, $constraint);
    }

    /**
     * Returns an Executioncontext
     *
     * @return \PHPUnit_Framework_MockObject_MockObject
     */
    private function getContext()
    {
        return $this->getMockBuilder('Symfony\Component\Validator\ExecutionContext')->disableOriginalConstructor()->getMock();
    }

    /**
     * Returns the TimezoneValidator
     *
     * @return \Lunetics\TimezoneBundle\Validator\TimezoneValidator
     */
    private function getTimezoneValidator()
    {
        $validator = new TimezoneValidator();
        $validator->initialize($this->context);

        return $validator;
    }
}