Capture console log of an iframe

Question

Is there a way to capture the console outside of an iframe?

I'm working on an online IDE similar to jsFiddle and I wanted to give the users to option to at least read the results of the javascript console.

Answer 1

Here is another solution if you don't want to append to HTML

var console = {
  __on : {},
  addEventListener : function (name, callback) {
    this.__on[name] = (this.__on[name] || []).concat(callback);
    return this;
  },
  dispatchEvent : function (name, value) {
    this.__on[name] = (this.__on[name] || []);
    for (var i = 0, n = this.__on[name].length; i < n; i++) {
      this.__on[name][i].call(this, value);
    }
    return this;
  },
  log: function () {
    var a = [];
    // For V8 optimization
    for (var i = 0, n = arguments.length; i < n; i++) {
      a.push(arguments[i]);
    }
    this.dispatchEvent("log", a);
  }
};

Outside the iframe

iframe.contentWindow.console.addEventListener("log", function (value) {
  console.log.apply(null, value);
});