Documentation for "authclient" extension has been extended.

extensions/yii/authclient/README.md

@@ -24,8 +24,8 @@ or add
 to the `require` section of your composer.json.
 
 
-Usage & Documentation
+Quick start
----------------------
+-----------
 
 This extension provides the ability of the authentication via external credentials providers.
 It covers OpenID, OAuth1 and OAuth2 protocols.
@@ -81,3 +81,218 @@ You may use [[yii\authclient\widgets\Choice]] to compose auth client selection:
      'baseAuthUrl' => ['site/auth']
 ]) ?>
 ```
+
+
+Base auth clients overview
+--------------------------
+
+This extension provides the base client class for each supported auth protocols:
+ - [[yii\authclient\OpenId]] supports [OpenID](http://openid.net/)
+ - [[yii\authclient\OAuth1]] supports [OAuth 1/1.0a](http://oauth.net/)
+ - [[yii\authclient\OAuth2]] supports [OAuth 2](http://oauth.net/2/)
+
+You may use these classes as they are to use external auth provider, or extend them
+in order to create some particular provider oriented client.
+
+Please, refer to the particular base client class documentation for its actual usage.
+
+Although, all clients are different they shares same basic interface [[yii\authclient\ClientInterface]],
+which governs some common API.
+
+Each client has some descriptive data, which can be used for different purposes:
+ - id - unique client id, which separates it from other clients, it could be used in URLs, logs etc.
+ - name - external auth provider name, which this client is match too. Different auth clients
+ can share the same name, if they refer to the same external auth provider.
+ For example: clients for Google OpenID and Google OAuth have same name "google".
+ This attribute can be used inside the database, CSS styles and so on.
+ - title - user friendly name for the external auth provider, it is used to present auth client
+ at the view layer.
+
+Each auth client has different auth flow, but all of them supports "getUserAttributes()" method,
+which can be invoked if authentication was successful.
+This method allows you to get information about external user account, such as id, email address,
+full name, preferred language etc.
+Defining list of attributes, which external auth provider should return, depends on client type:
+ - [[yii\authclient\OpenId]]: combination of "requiredAttributes" and "optionalAttributes"
+ - [[yii\authclient\OAuth1]] and [[yii\authclient\OAuth2]]: field "scope", note that different
+ providers use different formats for the scope.
+
+Each auth client has "viewOptions" attribute. It is an array, which stores name-value pairs,
+which serve to compose client representation in the view.
+For example widget [[yii\authclient\widgets\Choice]] uses keys "popupWidth" and "popupHeight" to
+determine the size of authentication popup window.
+
+
+External API usage
+------------------
+
+Both [[yii\authclient\OAuth1]] and [[yii\authclient\OAuth2]] provide method "api()", which
+can be used to access external auth provider REST API. However this method is very basic and
+it may be not enough to access full external API functionality. This method is mainly used to
+fetch the external user account data.
+To use API calls, you need to setup [[yii\authclient\BaseOAuth::apiBaseUrl]] according to the
+API specification. Then you can call [[yii\authclient\BaseOAuth::api()]] method:
+```
+use yii\authclient\OAuth2;
+
+$client = new OAuth2;
+...
+$client->apiBaseUrl = 'https://www.googleapis.com/oauth2/v1';
+$userInfo = $client->api('userinfo', 'GET');
+```
+
+
+Predefined auth clients
+-----------------------
+
+This extension provides the list of ready to use auth clients, which covers most
+popular external authentication providers. These clients are located under "yii\authclient\clients"
+namespace.
+
+Following predefined auth clients are available:
+ - [[yii\authclient\clients\Facebook]] - [Facebook](https://www.facebook.com/) OAuth2 client
+ - [[yii\authclient\clients\GitHub]] - [GitHub](https://github.com/) OAuth2 client
+ - [[yii\authclient\clients\GoogleOAuth]] - [Google](https://www.google.com/) OAuth2 client
+ - [[yii\authclient\clients\GoogleOpenId]] - [Google](https://www.google.com/) OpenID client
+ - [[yii\authclient\clients\LinkedIn]] - [LinkedIn](http://www.linkedin.com/) OAuth2 client
+ - [[yii\authclient\clients\LinkedIn]] - [LinkedIn](http://www.linkedin.com/) OAuth2 client
+ - [[yii\authclient\clients\Twitter]] - [Twitter](https://twitter.com/) OAuth1 client
+ - [[yii\authclient\clients\YandexOAuth]] - [Yandex](http://www.yandex.ru/) OAuth2 client
+ - [[yii\authclient\clients\YandexOpenId]] - [Yandex](http://www.yandex.ru/) OpenID client
+
+Please, refer to the particular client class documentation for its actual usage.
+
+
+Creating your own auth clients
+------------------------------
+
+You may create your own auth client for any external auth provider, which supports
+OpenId or OAuth protocol. To do so, first of all, you need to find out which protocol is
+supported by the external auth provider, this will give you the name of the base class
+for your extension:
+ - for OAuth 2 use [[yii\authclient\OAuth2]]
+ - for OAuth 1/1.0a use [[yii\authclient\OAuth1]]
+ - for OpenID use [[yii\authclient\OpenId]]
+
+At this stage you can determine auth client default name, title and view options, declaring
+corresponding methods:
+
+```
+use yii\authclient\OAuth2;
+
+class MyAuthClient extends OAuth2
+{
+	protected function defaultName()
+	{
+		return 'my_auth_client';
+	}
+
+	protected function defaultTitle()
+	{
+		return 'My Auth Client';
+	}
+
+	protected function defaultViewOptions()
+	{
+		return [
+			'popupWidth' => 800,
+			'popupHeight' => 500,
+		];
+	}
+}
+```
+
+Depending on actual base class, you will need to redeclare different fields and methods.
+
+1) [[yii\authclient\OpenId]]
+
+All you need is specify auth URL, by redeclaring "authUrl" field.
+You may also setup default required and/or optional attributes.
+For example:
+
+```
+use yii\authclient\OpenId;
+
+class MyAuthClient extends OpenId
+{
+	public $authUrl = 'https://www.my.com/openid/';
+
+	public $requiredAttributes = [
+		'contact/email',
+	];
+
+	public $optionalAttributes = [
+		'namePerson/first',
+		'namePerson/last',
+	];
+}
+```
+
+2) [[yii\authclient\OAuth2]]
+
+You will need to specify:
+- authorize URL - redeclare "authUrl" field
+- token request URL - redeclare "tokenUrl" field
+- API base URL - redeclare "apiBaseUrl" field
+- User attribute fetching strategy - redeclare "initUserAttributes" method
+
+For example:
+
+```
+use yii\authclient\OAuth2;
+
+class MyAuthClient extends OAuth2
+{
+	public $authUrl = 'https://www.my.com/oauth2/auth';
+
+	public $tokenUrl = 'https://www.my.com/oauth2/token';
+
+	public $apiBaseUrl = 'https://www.my.com/apis/oauth2/v1';
+
+	protected function initUserAttributes()
+	{
+		return $this->api('userinfo', 'GET');
+	}
+}
+```
+
+You may also specify default auth scopes.
+
+Note: some OAuth providers may not follow OAuth standards clearly, introducing
+some differences, which may require additional efforts to apply.
+
+3) [[yii\authclient\OAuth1]]
+
+You will need to specify:
+- authorize URL - redeclare "authUrl" field
+- request token URL - redeclare "requestTokenUrl" field
+- access token URL - redeclare "accessTokenUrl" field
+- API base URL - redeclare "apiBaseUrl" field
+- User attribute fetching strategy - redeclare "initUserAttributes" method
+
+For example:
+
+```
+use yii\authclient\OAuth1;
+
+class MyAuthClient extends OAuth1
+{
+	public $authUrl = 'https://www.my.com/oauth/auth';
+
+	public $requestTokenUrl = 'https://www.my.com/oauth/request_token';
+
+	public $accessTokenUrl = 'https://www.my.com/oauth/access_token';
+
+	public $apiBaseUrl = 'https://www.my.com/apis/oauth/v1';
+
+	protected function initUserAttributes()
+	{
+		return $this->api('userinfo', 'GET');
+	}
+}
+```
+
+You may also specify default auth scopes.
+
+Note: some OAuth providers may not follow OAuth standards clearly, introducing
+some differences, which may require additional efforts to apply.