Finished HATEOAS support.

docs/guide/rest.md

@@ -12,8 +12,8 @@ In particular, Yii provides support for the following aspects regarding RESTful
 * Support `OPTIONS` and `HEAD` verbs;
 * Authentication;
 * Authorization;
+* Support for HATEOAS;
 * Caching via `yii\web\HttpCache`;
-* Support for HATEOAS: TBD
 * Rate limiting: TBD
 * Searching and filtering: TBD
 * Testing: TBD

framework/base/Model.php

@@ -17,6 +17,8 @@ use yii\helpers\ArrayHelper;
 use yii\helpers\Inflector;
 use yii\validators\RequiredValidator;
 use yii\validators\Validator;
+use yii\web\Link;
+use yii\web\Linkable;
 
 /**
  * Model is the base class for data models.
@@ -876,6 +878,11 @@ class Model extends Component implements IteratorAggregate, ArrayAccess, Arrayab
 		foreach ($this->resolveFields($fields, $expand) as $field => $definition) {
 			$data[$field] = is_string($definition) ? $this->$definition : call_user_func($definition, $field, $this);
 		}
+
+		if ($this instanceof Linkable) {
+			$data['_links'] = Link::serialize($this->getLinks());
+		}
+
 		return $recursive ? ArrayHelper::toArray($data) : $data;
 	}
 

framework/data/Pagination.php

@@ -9,6 +9,8 @@ namespace yii\data;
 
 use Yii;
 use yii\base\Object;
+use yii\web\Link;
+use yii\web\Linkable;
 use yii\web\Request;
 
 /**
@@ -65,9 +67,8 @@ use yii\web\Request;
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class Pagination extends Object
+class Pagination extends Object implements Linkable
 {
-	const LINK_SELF = 'self';
 	const LINK_NEXT = 'next';
 	const LINK_PREV = 'prev';
 	const LINK_FIRST = 'first';
@@ -301,7 +302,7 @@ class Pagination extends Object
 		$currentPage = $this->getPage();
 		$pageCount = $this->getPageCount();
 		$links = [
-			self::LINK_SELF => $this->createUrl($currentPage, $absolute),
+			Link::REL_SELF => $this->createUrl($currentPage, $absolute),
 		];
 		if ($currentPage > 0) {
 			$links[self::LINK_FIRST] = $this->createUrl(0, $absolute);

framework/web/Link.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\web;
+
+use yii\base\Arrayable;
+use yii\base\Object;
+
+/**
+ * Link represents a link object as defined in [JSON Hypermedia API Language](https://tools.ietf.org/html/draft-kelly-json-hal-03).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class Link extends Object implements Arrayable
+{
+	/**
+	 * The self link.
+	 */
+	const REL_SELF = 'self';
+
+	/**
+	 * @var string a URI [RFC3986](https://tools.ietf.org/html/rfc3986) or
+	 * URI template [RFC6570](https://tools.ietf.org/html/rfc6570). This property is required.
+	 */
+	public $href;
+	/**
+	 * @var string a secondary key for selecting Link Objects which share the same relation type
+	 */
+	public $name;
+	/**
+	 * @var string a hint to indicate the media type expected when dereferencing the target resource
+	 */
+	public $type;
+	/**
+	 * @var boolean a value indicating whether [[href]] refers to a URI or URI template.
+	 */
+	public $templated = false;
+	/**
+	 * @var string a URI that hints about the profile of the target resource.
+	 */
+	public $profile;
+	/**
+	 * @var string a label describing the link
+	 */
+	public $title;
+	/**
+	 * @var string the language of the target resource
+	 */
+	public $hreflang;
+
+	/**
+	 * @inheritdoc
+	 */
+	public function toArray()
+	{
+		return array_filter((array)$this);
+	}
+
+	/**
+	 * Serializes a list of links into proper array format.
+	 * @param array $links the links to be serialized
+	 * @return array the proper array representation of the links.
+	 */
+	public static function serialize(array $links)
+	{
+		foreach ($links as $rel => $link) {
+			if (is_array($link)) {
+				foreach ($link as $i => $l) {
+					$link[$i] = $l instanceof self ? $l->toArray() : ['href' => $l];
+				}
+				$links[$rel] = $link;
+			} elseif (!$link instanceof self) {
+				$links[$rel] = ['href' => $link];
+			}
+		}
+		return $links;
+	}
+}

framework/web/Linkable.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\web;
+
+/**
+ * Linkable is the interface that should be implemented by classes that typically represent locatable resources.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+interface Linkable
+{
+	/**
+	 * Returns a list of links.
+	 *
+	 * Each link is either a URI or a [[Link]] object. The return value of this method should
+	 * be an array whose keys are the relation names and values the corresponding links.
+	 *
+	 * If a relation name corresponds to multiple links, use an array to represent them.
+	 *
+	 * For example,
+	 *
+	 * ```php
+	 * [
+	 *     'self' => 'http://example.com/users/1',
+	 *     'friends' => [
+	 *         'http://example.com/users/2',
+	 *         'http://example.com/users/3',
+	 *     ],
+	 *     'manager' => $managerLink, // $managerLink is a Link object
+	 * ]
+	 * ```
+	 *
+	 * @return array the links
+	 */
+	public function getLinks();
+}