protected function editInTemplateContext ($template, $field, callable $callback)
	{
		$template = $this->getTemplate($template);
		$fieldgroup = $template->fieldgroup;
		$field = $this->getField($field);

		$context = $fieldgroup->getField($field->name, true);
		$callback($context, $template);
		$this->fields->saveFieldgroupContext($context, $fieldgroup);
	}