NEW Many-many relation data editing in GridFieldDetailForm

Also adds GridFieldDetailForm->setFields() for customizing
the displayed form fields (required for adding relational fields).

docs/en/reference/grid-field.md

@@ -78,7 +78,7 @@ We will now move onto what the `GridFieldConfig`s are and how to use them.
 
 ----
 
-## GridFieldConfig
+## Configuration
 
 A gridfields's behaviour and look all depends on what config we're giving it. In the above example 
 we did not specify one, so it picked a default config called `GridFieldConfig_Base`.
@@ -98,7 +98,7 @@ A config object can be either injected as the fourth argument of the GridField c
 
 The framework comes shipped with some base GridFieldConfigs:
 
-### GridFieldConfig_Base
+### Table listing with GridFieldConfig_Base
 
 A simple read-only and paginated view of records with sortable and searchable headers.
 
@@ -107,7 +107,7 @@ A simple read-only and paginated view of records with sortable and searchable he
 
 The fields displayed are from `DataObject::getSummaryFields()`
 
-### GridFieldConfig_RecordViewer
+### Viewing records with GridFieldConfig_RecordViewer
 
 Similar to `GridFieldConfig_Base` with the addition support of:
 
@@ -118,7 +118,7 @@ The fields displayed in the read-only view is from `DataObject::getCMSFields()`
 	:::php
 	$gridField = new GridField('pages', 'All pages', SiteTree::get(), GridFieldConfig_RecordViewer::create());
 
-### GridFieldConfig_RecordEditor
+### Editing records with GridFieldConfig_RecordEditor
 
 Similar to `GridFieldConfig_RecordViewer` with the addition support of:
 
@@ -130,7 +130,7 @@ Similar to `GridFieldConfig_RecordViewer` with the addition support of:
 
 The fields displayed in the edit form are from `DataObject::getCMSFields()`
  
-### GridFieldConfig_RelationEditor
+### Editing relations with GridFieldConfig_RelationEditor
 
 Similar to `GridFieldConfig_RecordEditor`, but adds features to work on a record's has-many or 
 many-many relationships. As such, it expects the list used with the `GridField` to be a
@@ -147,9 +147,61 @@ The relations can be:
 
 The fields displayed in the edit form are from `DataObject::getCMSFields()`
 
+## Customizing Detail Forms
+
+The `GridFieldDetailForm` component drives the record editing form which is usually configured
+through the configs `GridFieldConfig_RecordEditor` and `GridFieldConfig_RelationEditor`
+described above. It takes its fields from `DataObject->getCMSFields()`,
+but can be customized to accept different fields via its `[api:GridFieldDetailForm->setFields()](api:setFields())` method.
+
+The component also has the ability to load and save data stored on join tables
+when two records are related via a "many_many" relationship, as defined through
+`[api:DataObject::$many_many_extraFields]`. While loading and saving works transparently,
+you need to add the necessary fields manually, they're not included in the `getCMSFields()` scaffolding.
+
+These extra fields act like usual form fields, but need to be "namespaced"
+in order for the gridfield logic to detect them as fields for relation extradata,
+and to avoid clashes with the other form fields.
+The namespace notation is `ManyMany[<extradata-field-name>]`, so for example
+`ManyMany[MyExtraField]`.
+
+Example:
+
+	:::php
+	class Player extends DataObject {
+		public static $db = array('Name' => 'Text');
+		public static $many_many = array('Teams' => 'Team');
+		public static $many_many_extraFields = array(
+			'Teams' => array('Position' => 'Text')
+		);
+		public function getCMSFields() {
+			$fields = parent::getCMSFields();
+
+			if($this->ID) {
+				$teamFields = singleton('Team')->getCMSFields();
+				$teamFields->addFieldToTab(
+					'Root.Main',
+					// Please follow the "ManyMany[<extradata-name>]" convention
+					new TextField('ManyMany[Position]', 'Current Position')
+				);
+				$config = GridFieldConfig_RelationEditor::create();
+				$config->getComponentByType('GridFieldDetailForm')->setFields($teamFields);
+				$gridField = new GridField('Teams', 'Teams', $this->Teams(), $config);
+				$fields->findOrMakeTab('Root.Teams')->replaceField('Teams', $gridField);
+			}
+
+			return $fields;
+		}
+	}
+
+	class Team extends DataObject {
+		public static $db = array('Name' => 'Text');
+		public static $many_many = array('Players' => 'Player');
+	}
+
 ## GridFieldComponents
 
-GridFieldComponents the actual workers in a gridfield. They can be responsible for:
+The `GridFieldComponent` classes are the actual workers in a gridfield. They can be responsible for:
 
  - Output some HTML to be rendered
  - Manipulate data

docs/en/reference/modeladmin.md

@@ -152,6 +152,8 @@ Consider replacing it with a more powerful interface in case you have many recor
 Has-many and many-many relationships are usually handled via the `[GridField](/reference/grid-field)` class,
 more specifically the `[api:GridFieldAddExistingAutocompleter]` and `[api:GridFieldRelationDelete]` components.
 They provide a list/detail interface within a single record edited in your ModelAdmin.
+The `[GridField](/reference/grid-field)` docs also explain how to manage 
+extra relation fields on join tables through its detail forms.
 
 ## Permissions
 

forms/gridfield/GridFieldDetailForm.php

@@ -28,6 +28,11 @@ class GridFieldDetailForm implements GridField_URLHandler {
 	 */
 	protected $validator;
 
+	/**
+	 * @var FieldList Falls back to {@link DataObject->getCMSFields()} if not defined.
+	 */
+	protected $fields;
+
 	/**
 	 * @var String
 	 */
@@ -127,6 +132,21 @@ class GridFieldDetailForm implements GridField_URLHandler {
 		return $this->validator;
 	}
 
+	/**
+	 * @param FieldList $fields
+	 */
+	public function setFields(FieldList $fields) {
+		$this->fields = $fields;
+		return $this;
+	}
+
+	/**
+	 * @return FieldList
+	 */
+	public function getFields() {
+		return $this->fields;
+	}
+
 	/**
 	 * @param String
 	 */
@@ -281,6 +301,8 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 	 * @return Form 
 	 */
 	public function ItemEditForm() {
+		$list = $this->gridField->getList();
+
 		if (empty($this->record)) {
 			$controller = Controller::curr();
 			$noActionURL = $controller->removeAction($_REQUEST['url']);
@@ -319,16 +341,25 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 				$actions->push(new LiteralField('cancelbutton', $text));
 			}
 		}
+		$fields = $this->component->getFields();
+		if(!$fields) $fields = $this->record->getCMSFields();
 		$form = new Form(
 			$this,
 			'ItemEditForm',
-			$this->record->getCMSFields(),
+			$fields,
 			$actions,
 			$this->component->getValidator()
 		);
-
+		
 		$form->loadDataFrom($this->record, $this->record->ID == 0 ? Form::MERGE_IGNORE_FALSEISH : Form::MERGE_DEFAULT);
 
+		// Load many_many extraData for record.
+		// Fields with the correct 'ManyMany' namespace need to be added manually through getCMSFields().
+		if($list instanceof ManyManyList) {
+			$extraData = $list->getExtraData('', $this->record->ID);
+			$form->loadDataFrom(array('ManyMany' => $extraData));
+		}
+		
 		// TODO Coupling with CMS
 		$toplevelController = $this->getToplevelController();
 		if($toplevelController && $toplevelController instanceof LeftAndMain) {
@@ -389,11 +420,19 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 	public function doSave($data, $form) {
 		$new_record = $this->record->ID == 0;
 		$controller = Controller::curr();
+		$list = $this->gridField->getList();
+		
+		if($list instanceof ManyManyList) {
+			// Data is escaped in ManyManyList->add()
+			$extraData = (isset($data['ManyMany'])) ? $data['ManyMany'] : null;
+		} else {
+			$extraData = null;
+		}
 
 		try {
 			$form->saveInto($this->record);
 			$this->record->write();
-			$this->gridField->getList()->add($this->record);
+			$list->add($this->record, $extraData);
 		} catch(ValidationException $e) {
 			$form->sessionMessage($e->getResult()->message(), 'bad');
 			$responseNegotiator = new PjaxResponseNegotiator(array(

tests/forms/gridfield/GridFieldDetailFormTest.php

@@ -106,6 +106,45 @@ class GridFieldDetailFormTest extends FunctionalTest {
 		$this->assertDOSContains(array(array('Surname' => 'Baggins')), $group->People());
 	}
 
+	public function testEditFormWithManyManyExtraData() {
+		$this->logInWithPermission('ADMIN');
+
+		// Lists all categories for a person
+		$response = $this->get('GridFieldDetailFormTest_CategoryController');
+		$this->assertFalse($response->isError());
+		$parser = new CSSContentParser($response->getBody());
+		$editlinkitem = $parser->getBySelector('.ss-gridfield-items .first .edit-link');
+		$editlink = (string) $editlinkitem[0]['href'];
+
+		// Edit a single category, incl. manymany extrafields added manually
+		// through GridFieldDetailFormTest_CategoryController
+		$response = $this->get($editlink);
+		$this->assertFalse($response->isError());
+		$parser = new CSSContentParser($response->getBody());
+		$editform = $parser->getBySelector('#Form_ItemEditForm');
+		$editformurl = (string) $editform[0]['action'];
+
+		$manyManyField = $parser->getByXpath('//*[@id="Form_ItemEditForm"]//input[@name="ManyMany[IsPublished]"]');
+		$this->assertTrue((bool)$manyManyField);
+		
+		$response = $this->post(
+			$editformurl,
+			array(
+				'Name' => 'Updated Category',
+				'ManyMany' => array('IsPublished' => 1),
+				'action_doSave' => 1
+			)
+		);
+		$this->assertFalse($response->isError());
+
+		$person = GridFieldDetailFormTest_Person::get()->sort('FirstName')->First();
+		$category = $person->Categories()->filter(array('Name' => 'Updated Category'))->First();
+		$this->assertEquals(
+			array('IsPublished' => 1),
+			$person->Categories()->getExtraData('', $category->ID)
+		);
+	}
+
 	public function testNestedEditForm() {
 		$this->logInWithPermission('ADMIN');
 
@@ -193,6 +232,12 @@ class GridFieldDetailFormTest_Person extends DataObject implements TestOnly {
 		'Categories' => 'GridFieldDetailFormTest_Category'
 	);
 
+	static $many_many_extraFields = array(
+		'Categories' => array(
+			'IsPublished' => 'Boolean'
+		)
+	);
+
 	static $default_sort = 'FirstName';
 
 	public function getCMSFields() {
@@ -289,5 +334,23 @@ class GridFieldDetailFormTest_GroupController extends Controller implements Test
 	}
 }
 
-class GridFieldDetailFormTest_ItemRequest extends GridFieldDetailForm_ItemRequest implements TestOnly {
+class GridFieldDetailFormTest_CategoryController extends Controller implements TestOnly {
+	protected $template = 'BlankPage';
+
+	public function Form() {
+		// GridField lists categories for a specific person
+		$person = GridFieldDetailFormTest_Person::get()->sort('FirstName')->First();
+		$detailFields = singleton('GridFieldDetailFormTest_Category')->getCMSFields();
+		$detailFields->addFieldToTab('Root.Main', new CheckboxField('ManyMany[IsPublished]'));
+		$field = new GridField('testfield', 'testfield', $person->Categories());
+		$field->getConfig()->addComponent($gridFieldForm = new GridFieldDetailForm($this, 'Form'));
+		$gridFieldForm->setFields($detailFields);
+		$field->getConfig()->addComponent(new GridFieldToolbarHeader());
+		$field->getConfig()->addComponent(new GridFieldAddNewButton('toolbar-header-right'));
+		$field->getConfig()->addComponent(new GridFieldEditButton());
+		return new Form($this, 'Form', new FieldList($field), new FieldList());
+	}
 }
+
+class GridFieldDetailFormTest_ItemRequest extends GridFieldDetailForm_ItemRequest implements TestOnly {
+}