Facebook 画布应用程序需要做的基本事情之一是检查权限并要求用户授权他们访问页面。有什么好方法可以做到这一点？
问问题
562 次
1 回答
0
这是我为自己的应用程序开发的系统。您可以从以下位置下载代码：
http://developsocialapps.com/permissions-and-basic-graph-api-calls/
这是完成繁重工作的图书馆。检查权限的主要方法是requireAuthorization。这将首先使用initOauthUserFromSignedRequest来查看是否有 signed_request 以查看使用是否经过身份验证并设置 userid 和 token。然后它将使用hasAllPermissions从图形 API 检查我/权限，以查看用户是否具有所有必需的权限。因为我不想在每次页面加载时都点击这个 API，所以我将权限存储在 cookie 中。如果用户没有权限或未被授权，它会将用户定向到授权对话框。
class FacebookApp {
public $appId;
private $appSecret;
private $nameSpace;
public $userId;
public $token;
public $tokenExpires;
// get your own from http://www.w3.org/P3P/
public $p3p = 'P3P:CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"';
/* construct object
appid, secret, and namespace from app settings */
public function __construct($id, $secret, $namespace) {
$this->appId = $id;
$this->appSecret = $secret;
$this->nameSpace = $namespace;
}
/* return json data from a graph api object or false */
function getGraphObject($object) {
$return = false;
$url = $this->getGraphUrl($object);
$response = $this->makeCurlRequest($url);
if ($repsonse !== false) {
$return = json_decode($response,true);
if (isset($return['error'])) {
$return = false;
// the request return an error, you can debug here
}
}
return $return;
}
/* constructs graphs url */
public function getGraphUrl($object,$limit=false) {
$url = "https://graph.facebook.com/".$object;
if (strpos($url,"?") === false) $url .= "?";
else $url .= "&";
$url .= "access_token=".$this->token;
if ($limit !== false) $url .= "&limit=".$limit;
return $url;
}
/* uses curl to get a url */
public function makeCurlRequest($url) {
$return = false;
try {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
$responseInfo = curl_getinfo($ch);
curl_close($ch);
if ($responseInfo['http_code']==200) {
$return = $response;
}
} catch (Exception $e) {
$return = false;
}
return $return;
}
/* sets userid and token from signed request, return true or false if authorized */
public function initOauthUserFromSignedRequest() {
$authorized = false;
if (isset($_REQUEST['signed_request'])) {
$data = $this->parseSignedRequest($_REQUEST['signed_request']);
if ($data !== false) {
if (isset($data['user_id']) && isset($data['oauth_token'])) {
$this->userId = $data['user_id'];
$this->token = $data['oauth_token'];
$this->tokenExpires = $data['expires'];
$authorized = true;
}
}
}
return $authorized;
}
/* require user to authorize and have permissions for page
redirect_uri = url to return after user has authorized like redirect.php
success_uri = url to redirect to on successful authorization like mypage.php
scope = comma separted list of permissions */
function requireAuthorization($redirect_uri,$success_uri=false,$scope=false) {
if ($success_uri === false) {
// if no success_uri use current page, all files for app must be in same directory
$success_uri = substr($_SERVER['REQUEST_URI'],strrpos($_SERVER['REQUEST_URI'],"/")+1);
}
$this->setCookie ("success_uri",$success_uri,0); // we will use this on the redirect_uri page
$requireauth = true;
if ($this->initOauthUserFromSignedRequest()) { // user has authorized
if (($scope === false) || ($this->hasAllPermissions($scope))) { // now check for perms
$requireauth = false;
}
}
if ($requireauth) { // user is either not authorized or doesn't have permissions
$url = $this->getAuthUrl($this->getCanvasUrl($redirect_uri),$scope);
echo "<html>\n<body>\n<script>\ntop.location.href='".$url."';\n</script></body></html>";
exit();
}
}
/* checks to see if has permissions, scope is comma separated list */
public function hasAllPermissions($scope) {
$return = false;
$cookiename = "permissions_".$this->appId."_".$this->userId;
$requiredpermissions = explode(",",$scope);
// first check cookie
if (isset($_COOKIE[$cookiename])) {
$return = true;
$permissions = json_decode($_COOKIE[$cookiename],true);
foreach ($requiredpermissions as $perm) {
if ($permissions['data'][0][$perm] != 1) {
$return = false;
break;
}
}
}
// if didn't have all in cookie, then see if it is in graph
if ($return == false) {
$permissions = $this->getGraphObject("me/permissions");
if ($permissions !== false) {
$this->setCookie($cookiename,json_encode($permissions),0);
$return = true;
foreach ($requiredpermissions as $perm) {
if ($permissions['data'][0][$perm] != 1) {
$return = false;
break;
}
}
}
}
return $return;
}
/* sets a cookie with p3p headers */
public function setCookie($name,$value,$expires) {
if ($this->p3p != '') {
header($this->p3p);
$this->p3p = '';
}
setcookie ($name,$value,$expires,"/");
}
/* returns url for oauth authorization
redirect_uri = url to return after user has authorized
scope = comma separted list of permissions */
public function getAuthUrl($redirect_uri,$scope=false) {
$url = "https://www.facebook.com/dialog/oauth/?client_id=".$this->appId."&redirect_uri=".rawurlencode($redirect_uri);
if ($scope !== false) $url .= "&scope=".rawurlencode($scope);
return $url;
}
/* returns url to app canvas page, $page like mypage.php?foo=bar */
public function getCanvasUrl($page) {
if ($_SERVER['HTTPS'] == "on") $protocol = "https";
else $protocol = "http";
return $protocol."://apps.facebook.com/".$this->nameSpace."/".$page;
}
/* parses signed_request parameter and returns data object, returns false if sigs don't match */
public function parseSignedRequest($signed_request) {
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
$data = json_decode(base64_decode(strtr($payload, '-_', '+/')), true);
$sig = base64_decode(strtr($encoded_sig, '-_', '+/'));
$expected_sig = hash_hmac('sha256', $payload, $this->appSecret, true);
if ($sig == $expected_sig) {
return $data;
} else {
return false;
}
}
}
在这样的页面上使用它：
$facebookapp = new FacebookApp("id1234...","secret...","appnamespace");
$facebookapp->requireAuthorization("redirect.php","thispage.php","user_about_me,user_likes,more_permissions");
redirect.php是一个页面，它将检测用户是否接受或取消了授权。如果接受，它将重定向回第一页，如果取消，它将显示一条消息。
<?php
require_once("../lib/facebookapp.php");
require_once("config.php");
$facebookapp = new FacebookApp($GLOBALS['facebookAppId'],$GLOBALS['facebookAppSecret'],$GLOBALS['facebookNamespace']);
if ((!isset($_GET['error'])) && isset($_GET['code'])) {
// user has auhtorized this app, go the the page from success_uri cookie
if (isset($_COOKIE['success_uri'])) $url = $facebookapp->getCanvasUrl($_COOKIE['success_uri']);
else $url = $facebookapp->getCanvasUrl('');
echo "<html>\n<body>\n<script>\ntop.location.href='".$url."';\n</script></body></html>";
exit();
}
?><html>
<body>
<h1>Permission Denied</h1>
<p>You have denied permissions to this app.</p>
<p><a href="<?php echo $facebookapp->getCanvasUrl(''); ?>" target="_top">Home</a></p>
</body>
</html>
于 2012-09-07T13:46:40.023 回答