javascript - FB.Event.subscribe ('auth.login' )不会每次都会触发？

Question

<div id="fb-root"></div>
    <script>
        window.fbAsyncInit = function() {
            FB.init({
                appId      : 'MY_APP_ID',
                status     : true,
                cookie     : true,
                xfbml      : true
            });

            FB.Event.subscribe('auth.login', function(response) {
               $.ajax({
                    url: "http://example.com/fbconnect",
                    success: function(){
                     window.location.reload();
        }
                 });
            });
        };
        (function(d){
            var js, id = 'facebook-jssdk'; if (d.getElementById(id)) {return;}
            js = d.createElement('script'); js.id = id; js.async = true;
            js.src = "//connect.facebook.net/en_US/all.js";
            d.getElementsByTagName('head')[0].appendChild(js);
        }(document));
    </script>


<div class="fb-login-button" data-perms="email,user_birthday,user_hometown,user_location">Login with Facebook</div>

它只适用于两种情况:

1. 当用户未登录并登录 Facebook 时，就会触发该事件。
2. 当用户登录但尚未授权该应用时，它会触发。

第三种不起作用的情况是当用户登录并且他已经授权该应用程序时，FB.Event.subscribe('auth.login')不会触发! !

Answer 1

我遇到了和你一样的事情，我发现了一个函数“getLoginStatus”，你可能会感兴趣。

当用户已经登录并授予您的应用所有权限时，无需再次登录，因此不会触发该事件。

但是，如果“getLoginStatus”的响应是“已连接”，则当用户已经登录并授予您的应用程序所有权限时，您可以执行您想做的操作。

完整的脚本可能如下所示:

<script>
  window.fbAsyncInit = function() {
    FB.init({
      appId      : 'APPID', // App ID
      channelUrl : 'CHANNEL_URL', // Channel File
      status     : true, // check login status
      cookie     : true, // enable cookies to allow the server to access the session
      xfbml      : true  // parse XFBML
    });

    FB.getLoginStatus(function(response) {
      if (response.status === 'connected') {
        // the user is logged in and connected to your
        // app, and response.authResponse supplies
        // the user's ID, a valid access token, a signed
        // request, and the time the access token 
        // and signed request each expire
        var uid = response.authResponse.userID;
        var accessToken = response.authResponse.accessToken;
        FB.api('/me', function(response) {
          if (response.name != undefined ) {
            console.log("Welcome, " + response.name);
          }         
        });
      } else if (response.status === 'not_authorized') {
        // the user is logged in to Facebook, 
        // but not connected to the app
      } else {
        // the user isn't even logged in to Facebook.
      }
    });        

    // Additional initialization code here

  };

  // Load the SDK Asynchronously
  (function(d){
     var js, id = 'facebook-jssdk'; if (d.getElementById(id)) {return;}
     js = d.createElement('script'); js.id = id; js.async = true;
     js.src = "//connect.facebook.net/en_US/all.js";
     d.getElementsByTagName('head')[0].appendChild(js);
   }(document));
</script>