Question

您好我正在编写代码以通过Facebook登录用户。我将所有函数与其他javascript函数一起存储在一个文件中。我尝试从另一个javascript函数调用登录函数并得到以下错误：登录未定义。这是index.html的代码

<html xmlns:fb="http://ogp.me/ns/fb#">
<head>
<script type="text/javascript" src="javascript.js"></script>
</head>
<body>
<div id="fb-root"></div>
<a href = "#" onClick = "sayhi();">Hi!</a>
</body>
</html>

这是javascript.js

window.fbAsyncInit = function() {
    // init the FB JS SDK
    FB.init({
      appId      : '213443452146381', // App ID from the App Dashboard
      channelUrl : '//http://abc.in/', // Channel File for x-domain communication
      status     : true, // check the login status upon init?
      cookie     : true, // set sessions cookies to allow your server to access the session?
      xfbml      : true  // parse XFBML tags on this page?
    });

    FB.getLoginStatus(function(response) {
    if (response.status === 'connected') 
    {
    alert('connected');
    } 
    else if (response.status === 'not_authorized') {
    alert('not_authorized');
    login();
    } else {
    alert('chillonly');
    login();
    }
    });

    function login() {
    FB.login(function(response) {
        if (response.authResponse) {
            alert('connected');
            testAPI();
        } else {
           alert('not_connected_login');
           testAPI();
        }
    });
    }
    function testAPI() {
    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me', function(response) {
        console.log('Good to see you, ' + response.name + '.');
    });
    }
    // Additional initialization code such as adding Event Listeners goes here

  };

  // Load the SDK's source Asynchronously
  // Note that the debug version is being actively developed and might 
  // contain some type checks that are overly strict. 
  // Please report such bugs using the bugs tool.
  (function(d, debug){
     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" + (debug ? "/debug" : "") + ".js";
     ref.parentNode.insertBefore(js, ref);
   }(document, /*debug*/ false));
// ]]>

function sayhi()
{
alert('Hi');
login();
}

我怀疑facebook jdk是否正在加载。请提出一种方法来实现这一目标。

Answer 1

方法login()无法访问，因为它位于本地范围内。

如果您希望在该范围之外使用function login() {，则需要将其设置为全局或部分全局命名空间。

更改

function login() {

到

window.login = function () {

Answer 2

首先，将这些函数移出window.fbAsyncInit。因为在当地范围内无法访问它们。
然后，您可以拥有一个仅在加载JS-SDK时设置为true的标志，并且您可以“阻止” window.fbAsyncInit 之外的任何进程直到该标志已设定。类似的东西：
```
var isLoaded = false;
window.fbAsyncInit = function() 
{
   isLoaded = true;
   ...
   ... 
}

function myFunc(myVar) 
{
  if(isLoaded) 
  {
  // Do FB related stuff
  }
}
```

将facebook javascript函数存储在文件中并使用它们

2 个答案: