How to know "who" executed this function

Question

In my Javascript code I have this

function log_function() {

   console.log("WHO FIRED ME");

}

window.alert = log_function;
window.open = log_function;
window.confirm = log_function;

Inside the function log_function I would like to know "who" fired the "log_function". Is it possible? I will assign that function to many more functions, so I would like to know who fired the log_function.

For example, if inside a page there is a script like:

alert("aaa");

I would like to know that it was the "alert" who was blocked and log it in the console.

possible duplicate of [How do you find out the caller function in JavaScript?](http://stackoverflow.com/questions/280389/how-do-you-find-out-the-caller-function-in-javascript) — Maximillian Laumeister, Sep 15 '15 at 19:52
@MaximillianLaumeister: that won't tell you the name of the global will it? — dandavis, Sep 15 '15 at 19:54

score 1 · Accepted Answer · answered Sep 15 '15 at 19:54

1

You could use a closure:

function log_function(caller) {
   return function() {
      console.log(caller + " FIRED ME");
   }
}

window.alert = log_function('alert');
window.open = log_function('open');
window.confirm = log_function('confirm');

answered Sep 15 '15 at 19:54

Ram

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it would not be practical cause I will be blocking many functions (probably around 300) and it would take too much time to do that. Isnt it possible something like arguments.callee? – gessicamilar Sep 15 '15 at 19:56
I like it. Clean and concise. – Brad Christie Sep 15 '15 at 19:56
1

@gessicamilar: you could feed it from an array of names, you don't have to hard-code each blocked var name... `["alert","confirm","whatev"].forEach(function(key){window[key]=log_function(key);})` does the same as the last 3 lines, but you can see how to expand it much more quickly... (or feed it something _like_ `Object.keys(window)`) – dandavis Sep 15 '15 at 20:02

score 0 · Answer 2 · answered Sep 15 '15 at 19:53

0

Could modify the context and pass along a describing property:

window.alert = function(){
  var _this = this || {};
  _this.caller = 'window.alert';
  log_function.apply(_this, arguments);
};
window.open = function(){
  var _this = this || {};
  _this.caller = 'window.open';
  log_function.apply(_this, arguments);
};
window.confirm = function(){
  var _this = this || {};
  _this.caller = 'window.confirm';
  log_function.apply(_this, arguments);
};

Then you can reference this.caller in your log method.

answered Sep 15 '15 at 19:53

Brad Christie

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Nice but it would still give me a hell of a job to block around 300 functions using 5 block of code for each function to block – gessicamilar Sep 15 '15 at 19:57
[`arguments.callee`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/callee) is acceptable, but from what I'm gathering it will give you trouble in strict mode. Not sure if that's a problem. However, [`arguments.caller`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/caller) is marked as troublesome. – Brad Christie Sep 15 '15 at 19:58
do you have any idea how I could achive tihs using arguments.callee ? I dont care about strict mode, it's an application that I will run under controlled circunstances. – gessicamilar Sep 15 '15 at 20:00
Callee is deprecated now that's what I read about the strict mode. – EasyBB Sep 15 '15 at 20:04

How to know "who" executed this function

2 Answers2