silverstripe-framework/forms/ToggleCompositeField.php

<?php

/**
 * Allows visibility of a group of fields to be toggled.
 *
 * @package forms
 * @subpackage fields-structural
 */
class ToggleCompositeField extends CompositeField {
	/**
	 * @var bool
	 */
	protected $startClosed = true;

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

	/**
	 * @param string $name
	 * @param string $title
	 * @param array|FieldList $children
	 */
	public function __construct($name, $title, $children) {
		$this->name = $name;
		$this->title = $title;

		parent::__construct($children);
	}

	/**
	 * @param array $properties
	 *
	 * @return HTMLText
	 */
	public function FieldHolder($properties = array()) {
		Requirements::javascript(FRAMEWORK_DIR . '/thirdparty/jquery/jquery.js');
		Requirements::javascript(FRAMEWORK_DIR . '/thirdparty/jquery-ui/jquery-ui.js');
		Requirements::javascript(FRAMEWORK_DIR . '/thirdparty/jquery-entwine/dist/jquery.entwine-dist.js');
		Requirements::javascript(FRAMEWORK_DIR . '/javascript/dist/ToggleCompositeField.js');

		Requirements::css(FRAMEWORK_DIR . '/thirdparty/jquery-ui-themes/smoothness/jquery-ui.css');

		$context = $this;

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

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

	/**
	 * {@inheritdoc}
	 */
	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 = $headingLevel;

		return $this;
	}
}