silverstripe-framework/Forms/FormTemplateHelper.php

<?php

namespace SilverStripe\Forms;

use SilverStripe\Core\Convert;
use ReflectionClass;
use SilverStripe\Core\Injector\Injectable;

/**
 * A helper class for managing {@link Form} and {@link FormField} HTML template
 * output.
 *
 * This primarily exists to maintain backwards compatibility between Form and
 * FormField template changes since developers may rely on specific HTML output
 * in their applications. Any core changes to templates (such as changing ID's)
 * may have the potential to silently prevent websites from working.
 *
 * To provide a form with a custom FormTemplateHelper use the following snippet:
 *
 * <code>
 * $form->setTemplateHelper('ClassName');
 * </code>
 *
 * Globally, the FormTemplateHelper can be set via the {@link Injector} API.
 */
class FormTemplateHelper {
	use Injectable;

	/**
	 * @param Form $form
	 *
	 * @return string
	 */
	public function generateFormID($form) {
		if($id = $form->getHTMLID()) {
			return Convert::raw2htmlid($id);
		}

		$reflection = new ReflectionClass($form);
		$shortName = str_replace(array('.', '/'), '', $form->getName());
		return Convert::raw2htmlid($reflection->getShortName() . '_' . $shortName);
	}

	/**
	 * @param FormField $field
	 *
	 * @return string
	 */
	public function generateFieldHolderID($field) {
		return $this->generateFieldID($field) . '_Holder';
	}

	/**
	 * Generate the field ID value
	 *
	 * @param FormField $field
	 * @return string
	 */
	public function generateFieldID($field) {
		if($form = $field->getForm()) {
			return sprintf("%s_%s",
				$this->generateFormID($form),
				Convert::raw2htmlid($field->getName())
			);
		}

		return Convert::raw2htmlid($field->getName());
	}

}