2012年1月4日更新

似乎你不能只调用依赖FB的方法（例如 FB.getAuthResponse（））在 FB.init（）之前就像以前一样，因为 FB.init（）似乎是异步的。将代码包裹到 FB.getLoginStatus（）响应似乎是在检测API完全准备就绪时的诀窍：

  window.fbAsyncInit = function（）{
 FB.init（{
 // ... 
}）; 

 FB.getLoginStatus（function（response）{
 runFbInitCriticalCode（）; 
}）; 

}; 
 

或者如果使用 fbEnsureInit（）以下：

  window.fbAsyncInit = function（）{
 FB.init（{
 //。 .. 
}）; 

 FB.getLoginStatus（function（response）{
 fbApiInit = true; 
}）; 

}; 
 

---

原始帖子如果你想在FB初始化时运行一些脚本，你可以在 fbAsyncInit 中放置一些回调函数：

  window.fbAsyncInit = function（）{
 FB.init（{
 appId：'& php echo $ conf ['fb'] ['appid'];？>'，
 status：true，//检查登录状态
 cookie：true，//启用Cookie以允许服务器访问会话
 xfbml：true //解析XFBML 
}）; 
 FB.Canvas.setAutoResize（）; 

 runFbInitCriticalCode（）; //包含FB init关键代码的函数
}; 
 

如果你想要确切地更换FB.ensureInit，那么你必须自己写一些东西，因为那里没有官方的替换（大错误imo）。这是我使用的：

  window.fbAsyncInit = function（）{
 FB.init（{
 appId：'<？php echo $ conf ['fb'] ['appid'];？>'，
 status：true，//检查登录状态
 cookie：true，//启用Cookie以允许服务器访问会话
 xfbml：true //解析XFBML 
}）; 
 FB.Canvas.setAutoResize（）; 

 fbApiInit = true; // init flag 
}; 

函数fbEnsureInit（callback）{
 if（！window.fbApiInit）{
 setTimeout（function（）{fbEnsureInit（callback）;}，50）; 
} else {
 if（callback）{
 callback（）; 
} 
} 
} 
 

用法：

  fbEnsureInit（function（）{
 console.log（一旦FB被初始化就运行）; 
 }）; 
 

The old JS SDK had a function called FB.ensureInit. The new SDK does not seem to have such function... how can I ensure that I do not make api calls until it is fully initiated?

I include this in the top of every page:

<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
    FB.init({
      appId  : '<?php echo $conf['fb']['appid']; ?>',
      status : true, // check login status
      cookie : true, // enable cookies to allow the server to access the session
      xfbml  : true  // parse XFBML
    });
    FB.Canvas.setAutoResize();
  };

  (function() {
    var e = document.createElement('script');
    e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
    e.async = true;
    document.getElementById('fb-root').appendChild(e);
  }());
</script>

Update on Jan 04, 2012

It seems like you can't just call FB-dependent methods (for example FB.getAuthResponse()) right after FB.init() like before, as FB.init() seems to be asynchronous now. Wrapping your code into FB.getLoginStatus() response seems to do the trick of detecting when API is fully ready:

window.fbAsyncInit = function() {
    FB.init({
        //...
    });

    FB.getLoginStatus(function(response){
        runFbInitCriticalCode(); 
    });

};  

or if using fbEnsureInit() implementation from below:

window.fbAsyncInit = function() {
    FB.init({
        //...
    });

    FB.getLoginStatus(function(response){
        fbApiInit = true;
    });

};  

---

Original Post:

If you want to just run some script when FB is initialized you can put some callback function inside fbAsyncInit:

  window.fbAsyncInit = function() {
    FB.init({
      appId  : '<?php echo $conf['fb']['appid']; ?>',
      status : true, // check login status
      cookie : true, // enable cookies to allow the server to access the session
      xfbml  : true  // parse XFBML
    });
    FB.Canvas.setAutoResize();

    runFbInitCriticalCode(); //function that contains FB init critical code
  };

If you want exact replacement of FB.ensureInit then you would have to write something on your own as there is no official replacement (big mistake imo). Here is what I use:

  window.fbAsyncInit = function() {
    FB.init({
      appId  : '<?php echo $conf['fb']['appid']; ?>',
      status : true, // check login status
      cookie : true, // enable cookies to allow the server to access the session
      xfbml  : true  // parse XFBML
    });
    FB.Canvas.setAutoResize();

    fbApiInit = true; //init flag
  };

  function fbEnsureInit(callback) {
        if(!window.fbApiInit) {
            setTimeout(function() {fbEnsureInit(callback);}, 50);
        } else {
            if(callback) {
                callback();
            }
        }
    }

Usage:

fbEnsureInit(function() {
    console.log("this will be run once FB is initialized");
});