BlogSearchWidget.php

<?php

if (class_exists("Widget")) {

	/**
	 * Class BlogSearchWidget
	 *
	 * @method Blog Blog()
	 */
	class BlogSearchWidget extends Widget {

		private static $cmsTitle = "Blog Search";

		private static $description = "Displays a keyword search of blog posts.";

		private static $title = "Search";

		private static $db = [
			'WidgetTitle' => 'Varchar'
		];

		private static $has_one = array(
			"Blog" => "Blog",
		);

		public function getCMSFields() {
			$fields = FieldList::create();
			$fields->merge(array(
				TextField::create("WidgetTitle", "Title"),
				DropdownField::create("BlogID", "Blog", Blog::get()->map())
			));
			$this->extend("updateCMSFields", $fields);
			return $fields;
		}

		public function Title() {
			return $this->WidgetTitle ? $this->WidgetTitle : self::$title;
		}

	}

	/**
	 * Class BlogSearchWidget_Controller
	 *
	 * @property BlogSearchWidget $widget
	 */
	class BlogSearchWidget_Controller extends WidgetController {

		private static $allowed_actions = [
			'BlogSearchForm',
			'doSearch'
		];

		public function BlogSearchForm() {
			$searchParam = Controller::curr()->request->getVar('search');
			$form = new Form(
				$this,
				'BlogSearchForm',
				new FieldList(
					(new TextField('Query', '', $searchParam))->setAttribute('required', 'required')
				),
				new FieldList(
					new FormAction('doSearch', 'Search')
				)
			);

			$form->setTemplate('BlogSearchForm');
			$form->disableSecurityToken();
			$form->setFormMethod('get');

			return $form;
		}

		public function doSearch($data, $form) {
			$query = $data['Query'];
			$blog = $this->widget->Blog();
			return $this->redirect($blog->Link("?search=$query"));

		}
	}

}