Question

我有一个脚本来显示某个网站的facebook登录按钮：

<html>
<head></head>
<body>
<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
  FB.init({
    appId      : 'myID', // App ID
    channelUrl : 'localhost:8080', // Channel File
    status     : true, // check login status
    cookie     : true, // enable cookies to allow the server to access the session
    xfbml      : true  // parse XFBML
  });

  // Here we subscribe to the auth.authResponseChange JavaScript event. This event is fired
  // for any authentication related change, such as login, logout or session refresh. This means that
  // whenever someone who was previously logged out tries to log in again, the correct case below 
  // will be handled. 
  FB.Event.subscribe('auth.authResponseChange', function(response) {
    // Here we specify what we do with the response anytime this event occurs. 
    if (response.status === 'connected') {
      // The response object is returned with a status field that lets the app know the current
      // login status of the person. In this case, we're handling the situation where they 
      // have logged in to the app.
      testAPI();
    } else if (response.status === 'not_authorized') {
      // In this case, the person is logged into Facebook, but not into the app, so we call
      // FB.login() to prompt them to do so. 
      // In real-life usage, you wouldn't want to immediately prompt someone to login 
      // like this, for two reasons:
      // (1) JavaScript created popup windows are blocked by most browsers unless they 
      // result from direct interaction from people using the app (such as a mouse click)
      // (2) it is a bad experience to be continually prompted to login upon page load.
      FB.login();
    } else {
      // In this case, the person is not logged into Facebook, so we call the login() 
      // function to prompt them to do so. Note that at this stage there is no indication
      // of whether they are logged into the app. If they aren't then they'll see the Login
      // dialog right after they log in to Facebook. 
      // The same caveats as above apply to the FB.login() call here.
      FB.login();
    }
  });
  };

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

  // Here we run a very simple test of the Graph API after login is successful. 
  // This testAPI() function is only called in those cases. 
  function testAPI() {
    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me', function(response) {
      console.log('Good to see you, ' + response.name + '.');
    });
  }
</script>

<!--
  Below we include the Login Button social plugin. This button uses the JavaScript SDK to
  present a graphical Login button that triggers the FB.login() function when clicked.

  Learn more about options for the login button plugin:
  /docs/reference/plugins/login/ -->

<fb:login-button show-faces="true" width="200" max-rows="1"></fb:login-button>
</body>
</html>

我收到了以下代码：

https://developers.facebook.com/docs/facebook-login/getting-started-web/

我是javascript的新手，并按原样复制脚本：并将其粘贴到我尝试使用浏览器查看的.html文件中。但我什么也没看到。请提出新的建议。

Answer 1

如果您在开发者工具中检查控制台，您将在facebook javascript代码中看到此警告：

Invalid App Id: Must be a number or numeric string representing the application id.

后面跟着这个javascript错误：

Uncaught TypeError: Cannot read property '1' of null

您必须使用您自己的数据替换代码中的这两行以使其正常工作：

appId      : 'myID', // App ID
channelUrl : 'localhost:8080', // Channel File

创建Facebook应用时，您将获得appId，如您要链接的教程所示。

此外，您需要指定channelUrl指向一个文件（例如channel.html，其中包含以下代码行：

<script src="//connect.facebook.net/en_US/all.js"></script>

但请仔细阅读您链接到的指南，而不是盲目地复制粘贴代码，您可能都会理解它并且能够在几分钟内使其工作：）

用于显示facebook登录按钮的Javascript代码无效

1 个答案: