Initial Form Field Schema implementation

- Adds FormSchema class
- Adds FormSchema dependency to LeftAndMain via Injector
- Adds schema allowed_action method to LeftAndMain for generating Form schemas
- Adds FormFieldSchemaTrait to for schema getters and setters on FormFields

_config/config.yml

@@ -1,6 +1,9 @@
 ---
 Name: coreconfig
 ---
+Injector:
+  FormSchema:
+    class: SilverStripe\Forms\Schema\FormSchema
 Upload:
   # Replace an existing file rather than renaming the new one.
   replaceFile: false

admin/code/LeftAndMain.php

@@ -5,6 +5,8 @@
  * @subpackage admin
  */
 
+use SilverStripe\Forms\Schema\FormSchema;
+
 /**
  * LeftAndMain is the parent class of all the two-pane views in the CMS.
  * If you are wanting to add more areas to the CMS, you can do it by subclassing LeftAndMain.
@@ -84,7 +86,7 @@ class LeftAndMain extends Controller implements PermissionProvider {
 	/**
 	 * @var array
 	 */
-	private static $allowed_actions = array(
+	private static $allowed_actions = [
 		'index',
 		'save',
 		'savetreenode',
@@ -97,7 +99,12 @@ class LeftAndMain extends Controller implements PermissionProvider {
 		'AddForm',
 		'batchactions',
 		'BatchActionsForm',
-	);
+		'schema',
+	];
+
+	private static $dependencies = [
+		'schema' => '%$FormSchema'
+	];
 
 	/**
 	 * @config
@@ -169,6 +176,15 @@ class LeftAndMain extends Controller implements PermissionProvider {
 	 */
 	protected $responseNegotiator;
 
+	/**
+	 * Gets a JSON schema representing the current edit form.
+	 *
+	 * @return SS_HTTPResponse
+	 */
+	public function schema() {
+		return $this->schema->getSchema($this->getEditForm());
+	}
+
 	/**
 	 * @param Member $member
 	 * @return boolean

forms/FormField.php

@@ -25,6 +25,8 @@
  */
 class FormField extends RequestHandler {
 
+	use SilverStripe\Forms\Schema\FormFieldSchemaTrait;
+
 	/**
 	 * @var Form
 	 */
@@ -80,7 +82,7 @@ class FormField extends RequestHandler {
 	 * @config
 	 * @var array $default_classes The default classes to apply to the FormField
 	 */
-	private static $default_classes = array();
+	private static $default_classes = [];
 
 
 	/**
@@ -162,7 +164,22 @@ class FormField extends RequestHandler {
 	 *
 	 * @var array
 	 */
-	protected $attributes = array();
+	protected $attributes = [];
+
+	/**
+	 * The type of front-end component to render the FormField as.
+	 *
+	 * @var string
+	 */
+	protected $schemaComponent;
+
+	/**
+	 * Structured schema data representing the FormField.
+	 * Used to render the FormField as a ReactJS Component on the front-end.
+	 *
+	 * @var array
+	 */
+	protected $schemaData = [];
 
 	/**
 	 * Takes a field name and converts camelcase to spaced words. Also resolves combined field

forms/FormFieldSchemaTrait.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace SilverStripe\Forms\Schema;
+
+trait FormFieldSchemaTrait {
+
+	/**
+	 * Sets the component type the FormField will be rendered as on the front-end.
+	 *
+	 * @param string $componentType
+	 * @return FormField
+	 */
+	public function setSchemaComponent($componentType) {
+		$this->schemaComponent = $componentType;
+		return $this;
+	}
+
+	/**
+	 * Gets the type of front-end component the FormField will be rendered as.
+	 *
+	 * @return string
+	 */
+	public function getSchemaComponent() {
+		return $this->schemaComponent;
+	}
+
+	/**
+	 * Sets the schema data used for rendering the field on the front-end.
+	 * Merges the passed array with the current `$schemaData` or {@link getSchemaDataDefaults()}.
+	 * Any passed keys that are not defined in {@link getSchemaDataDefaults()} are ignored.
+	 * If you want to pass around ad hoc data use the `data` array e.g. pass `['data' => ['myCustomKey' => 'yolo']]`.
+	 *
+	 * @param array $schemaData - The data to be merged with $this->schemaData.
+	 * @return FormField
+	 *
+	 * @todo Add deep merging of arrays like `data` and `attributes`.
+	 */
+	public function setSchemaData($schemaData = []) {
+		$current = $this->getSchemaData();
+
+		$this->schemaData = array_merge($current, array_intersect_key($schemaData, $current));
+		return $this;
+	}
+
+	/**
+	 * Gets the schema data used to render the FormField on the front-end.
+	 *
+	 * @return array
+	 */
+	public function getSchemaData() {
+		return array_merge($this->getSchemaDataDefaults(), $this->schemaData);
+	}
+
+	/**
+	 * Gets the defaults for $schemaData.
+	 * The keys defined here are immutable, meaning undefined keys passed to {@link setSchemaData()} are ignored.
+	 * Instead the `data` array should be used to pass around ad hoc data.
+	 *
+	 * @return array
+	 */
+	function getSchemaDataDefaults() {
+		return [
+			'type' => $this->class,
+			'component' => $this->getSchemaComponent(),
+			'id' => $this->ID,
+			'holder_id' => null,
+			'name' => $this->getName(),
+			'title' => $this->Title(),
+			'source' => null,
+			'extraClass' => $this->ExtraClass(),
+			'description' => $this->getDescription(),
+			'rightTitle' => $this->RightTitle(),
+			'leftTitle' => $this->LeftTitle(),
+			'readOnly' => $this->isReadOnly(),
+			'disabled' => $this->isDisabled(),
+			'customValidationMessage' => $this->getCustomValidationMessage(),
+			'attributes' => [],
+			'data' => [],
+		];
+	}
+}

forms/FormSchema.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace SilverStripe\Forms\Schema;
+
+use Convert;
+use Form;
+
+class FormSchema {
+
+	/**
+	 * Gets the schema for this form as a nested array.
+	 *
+	 * @param Form $form
+	 * @return string
+	 */
+	public function getSchema(Form $form) {
+		$request = $form->controller()->getRequest();
+		$params = $request->AllParams();
+
+		$schema = [
+			'name' => $form->getName(),
+			'id' => isset($params['ID']) ? $params['ID'] : null,
+			'action' => isset($params['Action']) ? $params['Action'] : null,
+			'method' => $form->controller()->getRequest()->HttpMethod(),
+			'schema_url' => $request->getUrl(),
+			'attributes' => $form->getAttributes(),
+			'data' => [],
+			'fields' => [],
+			'actions' => []
+		];
+
+		foreach ($form->Actions() as $action) {
+			$schema['actions'][] = $action->getSchemaData();
+		}
+
+		foreach ($form->Fields() as $fieldList) {
+			foreach ($fieldList->getForm()->fields()->dataFields() as $field) {
+				$schema['fields'][] = $field->getSchemaData();
+			}
+		}
+
+		return Convert::raw2json($schema);
+	}
+
+	/**
+	 * Gets the current state of this form as a nested array.
+	 *
+	 * @param From $form
+	 * @return string
+	 */
+	public function getState(Form $form) {
+		$state = ['state' => []];
+
+		return Convert::raw2json($state);
+	}
+}

tests/forms/FormFieldTest.php

@@ -241,6 +241,43 @@ class FormFieldTest extends SapphireTest {
 		$this->assertArrayHasKey('extended', $field->getAttributes());
 	}
 
+	public function testSetSchemaComponent() {
+		$field = new FormField('MyField');
+		$field = $field->setSchemaComponent('MyComponent');
+		$component = $field->getSchemaComponent();
+		$this->assertEquals('MyComponent', $component);
+	}
+
+	public function testGetSchemaDataDefaults() {
+		$field = new FormField('MyField');
+		$schema = $field->getSchemaDataDefaults();
+		$this->assertInternalType('array', $schema);
+	}
+
+	public function testGetSchemaData() {
+		$field = new FormField('MyField');
+		$schema = $field->getSchemaData();
+		$this->assertEquals('MyField', $schema['name']);
+
+		// Make sure the schema data is up-to-date with object properties.
+		$field->setName('UpdatedField');
+		$schema = $field->getSchemaData();
+		$this->assertEquals($field->getName(), $schema['name']);
+	}
+
+	public function testSetSchemaData() {
+		$field = new FormField('MyField');
+
+		// Make sure the user can update values.
+		$field = $field->setSchemaData(['name' => 'MyUpdatedField']);
+		$schema = $field->getSchemaData();
+		$this->assertEquals($schema['name'], 'MyUpdatedField');
+
+		// Make user the user can't define custom keys on the schema.
+		$field = $field->setSchemaData(['myCustomKey' => 'yolo']);
+		$schema = $field->getSchemaData();
+		$this->assertEquals(array_key_exists('myCustomKey', $schema), false);
+	}
 }
 
 /**

tests/forms/FormSchemaTest.php

@@ -0,0 +1,62 @@
+<?php
+
+use SilverStripe\Forms\Schema\FormSchema;
+
+class FormSchemaTest extends SapphireTest {
+
+	public function testGetSchema() {
+		$form = new Form(new Controller(), 'TestForm', new FieldList(), new FieldList());
+		$formSchema = new FormSchema();
+		$expectedJSON = json_encode([
+			'name' => 'TestForm',
+			'id' => null,
+			'action' => null,
+			'method' => '',
+			'schema_url' => '',
+			'attributes' => [
+				'id' => 'Form_TestForm',
+				'action' => 'Controller/TestForm',
+				'method' => 'POST',
+				'enctype' => 'application/x-www-form-urlencoded',
+				'target' => null,
+				'class' => ''
+			],
+			'data' => [],
+			'fields' => [
+				[
+					'type' => "HiddenField",
+					'component' => null,
+					'id' => null,
+					'holder_id' => null,
+					'name' => 'SecurityID',
+					'title' => 'Security ID',
+					'source' => null,
+					'extraClass' => 'hidden',
+					'description' => null,
+					'rightTitle' => null,
+					'leftTitle' => null,
+					'readOnly' => false,
+					'disabled' => false,
+					'customValidationMessage' => '',
+					'attributes' => [],
+					'data' => []
+				],
+			],
+			'actions' => []
+		]);
+
+		$schema = $formSchema->getSchema($form);
+
+		$this->assertJsonStringEqualsJsonString($expectedJSON, $schema);
+	}
+
+	public function testGetState() {
+		$form = new Form(new Controller(), 'TestForm', new FieldList(), new FieldList());
+		$formSchema = new FormSchema();
+		$expectedJSON = json_encode(['state' => []]);
+
+		$state = $formSchema->getState($form);
+
+		$this->assertJsonStringEqualsJsonString($expectedJSON, $state);
+	}
+}