Symfony TimezoneType表单

Question

In my symfony 3 application, User can choose their timezone in an form.

So i put it in my form like that:

    $builder
    ->add('timezone', TimezoneType::class)

It's working but i want to personnalize what user can choose in the list. Actually i see all country by continent. The list is too large with too many city.

I would like to have a shorter list with only main city and put the UTC before each city. Something like Twitter.

Example:

• (UTC) London
• (UTC+01:00) Paris
• (UTC+02:00) Athens
• (UTC+03:00) Moscow
• Etc ...

Does someone can help me on that?

Thanks

Answer 1

As you can see inside the Timezone Type, Symfony get the timezone this way:

private static function getFlippedTimezones()
{
    if (null === self::$timezones) {
        self::$timezones = array();

        foreach (\DateTimeZone::listIdentifiers() as $timezone) {
            $parts = explode('/', $timezone);

            if (count($parts) > 2) {
                $region = $parts[0];
                $name = $parts[1].' - '.$parts[2];
            } elseif (count($parts) > 1) {
                $region = $parts[0];
                $name = $parts[1];
            } else {
                $region = 'Other';
                $name = $parts[0];
            }

            self::$timezones[$region][str_replace('_', ' ', $name)] = $timezone;
        }
    }

    return self::$timezones;
}

You could create your own type or use it inside the form like

 $choices = self::getCustomFlippedTimezones();
 $builder
        ->add('timeZone', ChoiceType::class, array(
                'choices' => $choices
            ))

For reusability:

// src/AppBundle/Form/Type/CustomTimeZoneType.php
namespace AppBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Form\Extension\Core\Type\ChoiceType;

class CustomTimeZoneType extends AbstractType
{
    private static function getFlippedTimezones() { /*[...]*/}

    public function configureOptions(OptionsResolver $resolver)
    {

        $resolver->setDefaults(array(
            'choices' => self::getCustomFlippedTimezones(),
            'choices_as_values' => true,
        ));
    }

    public function getParent()
    {
        return ChoiceType::class;
    }
}