silverstripe-framework/Forms/ToggleCompositeField.php

<?php

namespace SilverStripe\Forms;

use SilverStripe\View\Requirements;

/**
 * Allows visibility of a group of fields to be toggled.
 *
 * Caution: The form field does not include any JavaScript or CSS when used outside of the CMS context,
 * since the required frontend dependencies are included through CMS bundling.
 */
class ToggleCompositeField extends CompositeField {
	/**
	 * @var bool
	 */
	protected $startClosed = true;

	/**
	 * @var int
	 */
	protected $headingLevel = 3;

	/**
	 * @inheritdoc
	 *
	 * @param string $name
	 * @param string $title
	 * @param array|FieldList $children
	 */
	public function __construct($name, $title, $children) {
		parent::__construct($children);
		$this->setName($name);
		$this->setTitle($title);
	}

	/**
	 * @inheritdoc
	 *
	 * @param array $properties
	 * @return string
	 */
	public function FieldHolder($properties = array()) {
		$context = $this;

		if(count($properties)) {
			$context = $this->customise($properties);
		}

		return $context->renderWith($this->getTemplates());
	}

	/**
	 * @inheritdoc
	 *
	 * @return array
	 */
	public function getAttributes() {
		$attributes = array(
			'id' => $this->ID(),
			'class' => $this->extraClass(),
		);

		if($this->getStartClosed()) {
			$attributes['class'] .= ' ss-toggle ss-toggle-start-closed';
		} else {
			$attributes['class'] .= ' ss-toggle';
		}

		return array_merge(
			$this->attributes,
			$attributes
		);
	}

	/**
	 * @return bool
	 */
	public function getStartClosed() {
		return $this->startClosed;
	}

	/**
	 * Controls whether the field is open or closed by default. By default the field is closed.
	 *
	 * @param bool $startClosed
	 *
	 * @return $this
	 */
	public function setStartClosed($startClosed) {
		$this->startClosed = (bool) $startClosed;

		return $this;
	}

	/**
	 * @return int
	 */
	public function getHeadingLevel() {
		return $this->headingLevel;
	}

	/**
	 * @param int $headingLevel
	 *
	 * @return $this
	 */
	public function setHeadingLevel($headingLevel) {
		$this->headingLevel = (int) $headingLevel;

		return $this;
	}
}