class InstitutionalHomePlugin extends GenericPlugin {

  public function register($category, $path, $mainContextId = null) {
		$success = parent::register($category, $path);
		if ($success && $this->getEnabled()) {

      // Use a hook to extend the context entity's schema
      HookRegistry::register('Schema::get::context', array($this, 'addToSchema'));

      // Use a hook to add a field to the masthead form in the journal/press settings.
      HookRegistry::register('Form::config::before', array($this, 'addToForm'));
		}
		return $success;
  }

  /**
   * Extend the context entity's schema with an institutionalHome property
   */
  public function addToSchema($hookName, $args) {
		$schema = $args[0];
		$schema->properties->institutionalHome = (object) [
			'type' => 'string',
			'apiSummary' => true,
			'multilingual' => true,
			'validation' => ['nullable']
		];

		return false;
  }

  /**
   * Extend the masthead form to add an institutionalHome input field
   * in the journal/press settings
   */
	public function addtoForm($hookName, $form) {

    // Only modify the masthead form
		if (!defined('FORM_MASTHEAD') || $form->id !== FORM_MASTHEAD) {
			return;
    }

    // Don't do anything at the site-wide level
		$context = Application::get()->getRequest()->getContext();
		if (!$context) {
			return;
    }

    // Add a field to the form
		$form->addField(new \PKP\components\forms\FieldText('institutionalHome', [
			'label' => 'Institutional Home',
			'groupId' => 'publishing',
			'value' => $context->getData('institutionalHome'),
		]));

		return false;
	}
}

$context = Application::get()->getRequest()->getContext();
$institutionalHome = $context->getLocalizedData('institutionalHome');