How can I override strings?

Question

I'm trying to change a label of Drupal 8's contact form ('Your email address'). The label is defined /core/modules/contact/src/MessageForm.php, but obviously I don't want to change this in core.

$form['mail'] = array(
'#type' => 'email',
'#title' => $this->t('Your email address'),
'#required' => TRUE,
);

In Drupal 7 I always used string overrides but the module isn't available for Drupal 8 yet. How can string be overridden in Drupal 8?

Answer 1

The easiest method would be to implement a hook_form_alter inside a custom module that overrides the title

https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Form%21form.api.php/function/hook_form_alter/8.2.x

Some information how to create custom module.

https://www.drupal.org/docs/8/creating-custom-modules

Answer 2

You can always override strings in settings.php like this:

$settings['locale_custom_strings_en'][''] = array(
  'Related entities for @group' => 'Add Content to group @group',
);

You can change en to de or whatever two letter language code you like.

Please note: the entire string must exist by itself. For example, the above string override existed in the group module controller like this:

return $this->t('Related entities for @group', ['@group' => $group->label()]);

This will NOT work:

$settings['locale_custom_strings_en'][''] = array(
  'Related entities for ' => 'Add Content to ',
);

So for the example listed in the question, you could use:

$settings['locale_custom_strings_en'][''] = array(
  'Your email address' => 'Your email ID',
);