Set Required and Optional Address Inputs for Address Field in Drupal 8

18 Jan · by Tim Kamanin · 2 min read

This one is dedicated to all my fellow Drupalers. There's no better exercise for a brain than ~~reading ancient chinese poetry~~ taming Drupal 8. When I 'm bored, I turn to Drupal!

Recently I got my Drupal 8 Address module updated and it turned out that from now on street address and postal code inputs are required by default. But my requirement is to have only a "city" input required. How do I do that? Well it's not that easy as you might think (form alter / widget alter won't help you there) and there's no UI for that (as of now). After spending some time deep in the ~~sh..~~ code, I've figured out that ALL you need is to just simply create an EventSubscriber and declare your required fields there. Sssssimple!

Okay, enough talking, let me show it to you:

Step 1

Create a file with the following path: your_module/src/EventSubscriber/AddressFormatSubscriber.php

Step 2

Put this code inside a previously created file:

namespace Drupal\pabc_glue\EventSubscriber;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Drupal\address\Event\AddressEvents;

class AddressFormatSubscriber implements EventSubscriberInterface {

  static function getSubscribedEvents() {
    $events[AddressEvents::ADDRESS_FORMAT][] = array('onGetDefinition', 0);
    return $events;

  public function onGetDefinition($event) {
    $definition = $event->getDefinition();
    // This makes city (locality) field required and leaves
    // the rest address fields as optional
    $definition['required_fields'] = ['locality'];


Note line 18, this is where we declare our required fields.

Step 3

Create, or alter already existing, file

Step 4

Declare your newly created AddressFormatSubscriber service in

Step 5

Coffee time ☕️ - clear your caches!


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B. Kat

Is there a way to customize the required address components on a per field basis? For example, for a birthplace, I just want city/state (for US birthplaces) but some others I may want the standard required fields.

Reply · 1 month, 1 week ago

Can't get this to work ... Functions are never called, can't figure out why.

Reply · 1 month, 1 week ago
Michael W.

This is great, Tim, thanks! Saved me loads of time futzing about with the address field.

Reply · 1 month, 1 week ago

Duuuude, you're a lifesaver!

Reply · 10 months, 2 weeks ago