fnObj = window [functionName]不是函数问题 - eval（）效果很好

I'm just overworking my JS code and wish to replace my eval()'s with window[functionName]. So I just made a quick test in the JSFiddle and all works well with the following lines:

我只是过度使用我的JS代码,并希望用window [functionName]替换我的eval()。所以我刚刚在JSFiddle中进行了快速测试,并且所有方法都适用于以下几行:

var fnName = "Page_test";
var foo = "yammy";
var Page_test = function(bar) {
    return bar;
}
var Obj = window[fnName];
alert(Obj(foo));

(Link to this JSFiddle -> http://jsfiddle.net/juSHj/)

(链接到这个JSFiddle - > http://jsfiddle.net/juSHj/)

Now I try to replace the following lines of code with the evil eval() with the above concept:

现在我尝试使用上述概念将邪恶的eval()替换为以下代码行:

old code: (works like a charm / fired after ajax success)

旧代码:(工作就像魅力/ ajax成功后解雇)

 ...
 success: function(ret) {
     if(returnFnAjaxForm != "") {
          eval(returnFnAjaxForm+"('"+encodeURI(jQuery.trim(ret))+"')");
     }
 }
 ...

new code:

Returns: Uncaught TypeError: Property 'dummyFn' of object [object Window] is not a function

返回:未捕获的TypeError:对象[对象窗口]的属性'dummyFn'不是函数

...
success: function(ret) {
     if(returnFnAjaxForm != "") {
          fnObj = window[returnFnAjaxForm];
          if(typeof(fnObj) == "function") { // this is optional
               fnObj(encodeURI(jQuery.trim(ret)));
          }
     }
} 
...

I'm curious where I made my mistake. Yes the function I try to fire exists and is defined with var . Is this concept may not possible to use it on an ajax-response?

我很好奇我犯了哪些错误。是的,我尝试触发的功能存在,并使用var定义。这个概念可能无法在ajax响应中使用它吗?

Thanks for any help.

谢谢你的帮助。

(Using jQuery)

1 个解决方案

#1

If you declare your function in a closure, it's not a member of window. Example :

如果在闭包中声明函数,则它不是窗口的成员。示例:

var in_window = '132';
alert(window['in_window']); // Alert 132

(function() {
    var not_in_window = '132';
    alert(window['not_in_window']); // Alert undefined
})();

So be careful of where you declare your Page_test variable. If you really want to put in window, you can do window.Page_test = Page_test.

因此,请注意声明Page_test变量的位置。如果你真的想放入窗口,你可以做window.Page_test = Page_test。

The best you can do is to use an object for all your possible callbacks. Like this :

您可以做的最好的事情是使用一个对象来进行所有可能的回调。喜欢这个 :

var callbacks = {
    foo : function() {},
    foo1 : function() {},
    foo2 : function() {},
    foo3 : function() {}
};

var obj = callbacks[fnName];

#1