Add utility request handler class

README.md

@@ -3,11 +3,17 @@ SilverStripe Grid Field Extensions Module
 
 This module provides a number of useful grid field components:
 
-* `GridFieldAddExistingSearchButton` - a more advanced search form for adding items.
-* `GridFieldAddNewInlineButton` - builds on `GridFieldEditableColumns` to allow inline creation of records.
-* `GridFieldAddNewMultiClass` - lets the user select from a list of classes to create a new record from.
+* `GridFieldAddExistingSearchButton` - a more advanced search form for adding
+  items.
+* `GridFieldAddNewInlineButton` - builds on `GridFieldEditableColumns` to allow
+  inline creation of records.
+* `GridFieldAddNewMultiClass` - lets the user select from a list of classes to
+  create a new record from.
 * `GridFieldEditableColumns` - allows inline editing of records.
 * `GridFieldOrderableRows` - drag and drop re-ordering of rows.
+* `GridFieldRequestHandler` - a basic utility class which can be used to build
+  custom grid field detail views including tabs, breadcrumbs and other CMS
+  features.
 * `GridFieldTitleHeader` - a simple header which displays column titles.
 
 See [docs/en/index.md](docs/en/index.md) for documentation and examples.

code/GridFieldRequestHandler.php

@@ -0,0 +1,147 @@
+<?php
+/**
+ * A base utility class for request handlers which present a grid field detail
+ * view.
+ *
+ * This class provides some useful defaults for grid field detail views, such
+ * as tabs, breadcrumbs and a back link. Much of this code is extracted from the
+ * detail form.
+ */
+abstract class GridFieldRequestHandler extends RequestHandler {
+
+	/**
+	 * @var GridField
+	 */
+	protected $grid;
+
+	/**
+	 * @var GridFieldComponent
+	 */
+	protected $component;
+
+	/**
+	 * @var string
+	 */
+	protected $name;
+
+	/**
+	 * @var string
+	 */
+	protected $template = __CLASS__;
+
+	public function __construct(GridField $grid, GridFieldComponent $component, $name) {
+		$this->grid = $grid;
+		$this->component = $component;
+		$this->name = $name;
+
+		parent::__construct();
+	}
+
+	public function index($request) {
+		$result = $this->renderWith($this->template);
+
+		if($request->isAjax()) {
+			return $result;
+		} else {
+			return $this->getTopLevelController()->customise(array(
+				'Content' => $result
+			));
+		}
+	}
+
+	public function Link($action = null) {
+		return Controller::join_links($this->grid->Link(), $this->name, $action);
+	}
+
+	/**
+	 * This method should be overloaded to build out the detail form.
+	 *
+	 * @return Form
+	 */
+	public function Form() {
+		$form = new Form(
+			$this,
+			'Form',
+			new FieldList($root = new TabSet('Root', new Tab('Main'))),
+			new FieldList()
+		);
+
+		if($this->getTopLevelController() instanceof LeftAndMain) {
+			$form->setTemplate('LeftAndMain_EditForm');
+			$form->addExtraClass('cms-content cms-edit-form cms-tabset center');
+			$form->setAttribute('data-pjax-fragment', 'CurrentForm Content');
+
+			$root->setTemplate('CMSTabSet');
+			$form->Backlink = $this->getBackLink();
+		}
+
+		return $form;
+	}
+
+	/**
+	 * @return Controller
+	 */
+	public function getController() {
+		return $this->grid->getForm()->getController();
+	}
+
+	/**
+	 * @param string $template
+	 */
+	public function setTemplate($template) {
+		$this->template = $template;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getTemplate() {
+		return $this->template;
+	}
+
+	/**
+	 * @return ArrayList
+	 */
+	public function getBreadcrumbs() {
+		$controller = $this->getController();
+
+		if($controller->hasMethod('Breadcrumbs')) {
+			return $controller->Breadcrumbs();
+		} else {
+			return new ArrayList();
+		}
+	}
+
+	/**
+	 * @return string
+	 */
+	protected function getBackLink() {
+		$controller = $this->getTopLevelController();
+
+		if($controller->hasMethod('Backlink')) {
+			return $controller->Backlink();
+		} else {
+			return $controller->Link();
+		}
+	}
+
+	/**
+	 * @return Controller
+	 */
+	protected function getTopLevelController() {
+		$controller = $this->getController();
+
+		while($controller) {
+			if($controller instanceof GridFieldRequestHandler) {
+				$controller = $controller->getController();
+			} elseif($controller instanceof GridFieldDetailForm_ItemRequest) {
+				$controller = $controller->getController();
+			} else {
+				break;
+			}
+		}
+
+		return $controller;
+	}
+
+}

templates/GridFieldRequestHandler.ss

@@ -0,0 +1,5 @@
+<% if $BackLink %>
+	<a href="$BackLink"><%t GridFieldExtensions.BACK "Back" %></a>
+<% end_if %>
+
+$Form