GridFieldCustomSiteTreeAddNewButton.php

<?php

class GridFieldCustomSiteTreeAddNewButton extends GridFieldAddNewButton implements GridField_ActionProvider {

	/** @var  SiteTree */
	protected $parentPage;

	public function __construct($targetFragment = 'before', SiteTree $parent) {
		parent::__construct($targetFragment);
		$this->parentPage = $parent;
	}

	public function getHTMLFragments($gridField) {
		/** @var GridField $gridField */

		$state = $gridField->State->GridFieldCustomSiteTreeAddNewButton;

		if ($this->parentPage) {
			$state->currentPageID = $this->parentPage->ID;
		}

		$pageTypes       = HiddenField::create('PageType', 'Page Type', 'WinePage');
		$state->pageType = 'WinePage';

		$this->buttonName = 'Add New Wine';

		$addAction = new GridField_FormAction($gridField, 'add', $this->buttonName, 'add', 'add');
		$addAction->setAttribute('data-icon', 'add')->addExtraClass("no-ajax ss-ui-action-constructive dropdown-action");

		$forTemplate         = new ArrayData(array());
		$forTemplate->Fields = new ArrayList();
		$forTemplate->Fields->push($pageTypes);
		$forTemplate->Fields->push($addAction);

		return array($this->targetFragment => $forTemplate->renderWith("GridFieldSiteTreeAddNewButton"));
	}


	/**
	 * Provide actions to this component.
	 *
	 * @param GridField $gridField
	 *
	 * @return array
	 **/
	public function getActions($gridField) {
		return ["add"];
	}


	/**
	 * Handles the add action, but only acts as a wrapper for {@link CMSPageAddController::doAdd()}
	 *
	 * @param GridField $gridField
	 * @param string    $actionName
	 * @param mixed     $arguments
	 * @param array     $data
	 **/
	public function handleAction(GridField $gridField, $actionName, $arguments, $data) {

		if ($actionName == "add") {
			$tmpData = json_decode($data[$gridField->getName()]['GridState'], true);
			$tmpData = $tmpData['GridFieldCustomSiteTreeAddNewButton'];

			$data = array(
				"ParentID" => $tmpData['currentPageID'],
				"PageType" => $tmpData['pageType']
			);

			$controller = Injector::inst()->create("CMSPageAddController");

			$form = $controller->AddForm();
			$form->loadDataFrom($data);

			$controller->doAdd($data, $form);
			$response = $controller->getResponseNegotiator()->getResponse();

			// Get the current record
			$record = SiteTree::get()->byId($controller->currentPageID());
			if ($record) {
				$response->redirect(Director::absoluteBaseURL() . $record->CMSEditLink(), 301);
			}

			return $response;

		}
	}

}