此文分為兩個單元
1 使用Yahoo OAuth2 1/2
2 使用Yahoo OAuth2 2/2

前文已申請完yahoo的api後，接下來實作的部分，原先我參考了Jex’s note 不寫下來絕對會忘…的內容，原先我也如他的原先以為只要照著做，就能順利的運作，所以我就照著他的範例來做，但是怎麼試都會出現ERROR：

$session = YahooSession::requireSession(OAUTH::CONSUMER_KEY, OAUTH::CONSUMER_SECRET, OAUTH::APP_ID);

這裡面的YahooSession到底是什麼東西啊，為什麼突然出現？後來發現它引入https://github.com/yahoo/yos-social-php/blob/master/lib/OAuth.php這個library，它的年代已經過去，同時它的方法是用YQL的方式取回資料，所以我就和Jex說的一樣：我只好參考網路的資源重刻了一個輪子：

使用OAuth2的方法來作認證

雖然Jex無法解決我的問題，但摸索中也了解了oauth2的運作，這比直接得到一個輪子有意思。以下和Jex一樣，使用CI3作為範例：

四、建立一個library

這個library 來自於[3] 由saurabhsahni寫的library，/application/libraries/Yahoooauth2.php

<?php
/*
Example class to access Yahoo OAuth2 protected APIs, based on https://developer.yahoo.com/oauth2/guide/
Find documentation and support on Yahoo Developer Network: https://developer.yahoo.com/forums
*/
class YahooOAuth2 {
  const AUTHORIZATION_ENDPOINT  = 'https://api.login.yahoo.com/oauth2/request_auth';
  const TOKEN_ENDPOINT   = 'https://api.login.yahoo.com/oauth2/get_token';
  public function fetch($url,$postdata="",$auth="",$headers="") {
        $curl = curl_init($url);
        if($postdata) {
            curl_setopt($curl, CURLOPT_POST, true);
            curl_setopt($curl, CURLOPT_POSTFIELDS, http_build_query($postdata));
        }
        else {
            curl_setopt($curl, CURLOPT_POST, false);
        }
        if($auth){
            curl_setopt($curl, CURLOPT_USERPWD, $auth);
        }
        if($headers){
            curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
        }
        curl_setopt($curl, CURLOPT_HEADER, false);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        $response = curl_exec( $curl );
        if (empty($response)) {
            // some kind of an error happened
            die(curl_error($curl));
            curl_close($curl); // close cURL handler
        } else {
            $info = curl_getinfo($curl);
            curl_close($curl); // close cURL handler
            if($info['http_code'] != 200 && $info['http_code'] != 201 ) {
                echo "Received error: " . $info['http_code']. "\n";
                echo "Raw response:".$response."\n";
                die();
            }
        }
        return $response;
  }
  public function getAuthorizationURL($client_id,$redirect_uri,$language="en-us") {
        $url = self::AUTHORIZATION_ENDPOINT;
        $authorization_url=$url.'?'.'client_id='.$client_id.'&redirect_uri='.$redirect_uri.
        '&language='.$language.'&response_type=code';
        return $authorization_url;
  }
  public function get_access_token($clientId, $clientSecret,$redirect_uri,$code) {
        $url=self::TOKEN_ENDPOINT;
        $postdata=array("redirect_uri"=>$redirect_uri,"code"=>$code,"grant_type"=>"authorization_code");
        $auth=$clientId . ":" . $clientSecret;
        $response=self::fetch($url,$postdata,$auth);
        // Convert the result from JSON format to a PHP array
        $jsonResponse = json_decode( $response );
        return $jsonResponse->access_token;
  }
}
?>

五、controller的部分，放在你的 controller function中

        $this->load->library('Yahoooauth2');
        define("CONSUMER_KEY", $this->config->item("yahoo_consumer_key"));
        define("CONSUMER_SECRET",$this->config->item("yahoo_consumer_secret"));
        $redirect_uri="http://".$_SERVER['SERVER_NAME'] . "/auth/login?step=8";  //設定你的回呼路徑
        $social_endpoint = "https://social.yahooapis.com/v1/user/me/profile?format=json";
        if (isset($_GET['code'])){
          $code=$_GET['code'];
        }
        else {
          $code=0;
        }
        if($code){
          try{
            #oAuth 3-legged authorization is successful, fetch access token
            $token=$this->yahoooauth2->get_access_token(CONSUMER_KEY,CONSUMER_SECRET,$redirect_uri,$code);
            #access token is available. Do API calls.
            $headers= array(
                'Authorization: Bearer '.$token,
                'Accept: application/json',
                'Content-Type: application/json'
            );
            //Fetch Advertiser Name and Advertiser ID
            $resp=$this->yahoooauth2->fetch($social_endpoint,$postdata="",$auth="",$headers);
            $jsonResponse = json_decode( $resp);
            $email = $jsonResponse->profile->emails[0]->handle;
            $name = $jsonResponse->profile->familyName .  $jsonResponse->profile->givenName;
            $gender =  ($jsonResponse->profile->gender=="M")? 1:0;
            $thumb = $jsonResponse->profile->image->imageUrl;
            $guid =  $jsonResponse->profile->guid;
         }catch(Exception $e){
              $msg= "Yahoo認證失敗：".$e->getMessage();
         }finally{
            print $msg;
         }
        }
        else {
        /* no valid access token available, go to authorization server */
          header("HTTP/1.1 302 Found");
          header("Location: " . $this->yahoooauth2->getAuthorizationURL(CONSUMER_KEY,$redirect_uri));
          exit;
        }

簡略說明：
2,3 行我把key/secret的值放在config中
4 設定你的回呼路徑
6-11,36-41 如果yahoo沒有回傳code，則導到yahoo進行授權確認
24 取得回呼的資料，是一個物件
25-29 回呼內容，可參考下面的物件內容：

六、取得的物件資料

能夠取得這麼完整的資料，相信你一定會很高興，祝你們使用愉快

參考資料

[3] https://github.com/saurabhsahni/php-yahoo-oauth2

原文 2016-04-05 00:04:26