在facebook api回调的上下文？ [英] Context on facebook api callback?

问题描述

有没有办法在javascript facebook sdk api回调中传递上下文？这是一个简单的例子。现在这将不起作用，因为我的回调函数中的变量'this.name'将是未定义的，因为它不在我的用户对象上下文中。任何想法如何做？

  function user（id）{
 this.id = id; 
 this.getUserName = function（fields，callback）{
 FB.api（{
 method：'fql.query'，
 query：'SELECT'+ fields.toString ）+'FROM profile WHERE id ='+ this.id 
}，
 callback 
）; 
} 
 this.getUserName（['name']，function（response）{this.name = response [0] .name;}）; 
} 
 
 var amigo = new user（'fb_id_here'）; 
  

解决方案

编辑：这只是解。 Apply（）可以与闭包一起使用，以返回绑定到对象范围的函数（请参阅Jamie的帖子）。

Ex：

  function bindScope = function（context，obj）
 {
 return function（）
 {
 return obj.apply（context）; 
} 
} 
  

我相信你可以使用javascript的apply ）。尝试将第8行改为callback.apply（this）。

上下文资源申请 - http://kossovsky.net/index .php / 2009/07 / function-context-and-apply-function /

Is there a way to pass context in a javascript facebook sdk api callback? Here's a simple exemple. Now this won't work because the variable 'this.name' in my callback function would be undefined, because it's not in my user object context. Any idea how to do it?

function user(id) {
 this.id = id;
 this.getUserName = function(fields,callback){
   FB.api({
     method:'fql.query',
     query: 'SELECT '+ fields.toString() +' FROM profile WHERE id=' + this.id
     },
     callback
   );
 }
 this.getUserName(['name'],function(response){this.name = response[0].name;});
}

var  amigo = new user('fb_id_here');

解决方案

Edit: This is only part of the solution. Apply() can be used with closures to return a function that is bound to an object's scope (see Jamie's post).

Ex:

function bindScope = function(context, obj)
{
    return function()
    {
        return obj.apply(context);
    }
}

I believe you can change the context using javascript's apply(). Try changing line #8 to callback.apply(this).

Resource on context & apply - http://kossovsky.net/index.php/2009/07/function-context-and-apply-function/

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