Question

I am currently building a browser extension that injects javascript/jquery into certain pages, and i am having a weird issue, where forcing .click() events are not working from my injected code. The strange bit is that it works completely fine if i make the call from my console js console.

I dont really understand what the problem is. It seems that all of my other calls are working fine. I can bind to click events using .click(function(){...}) (so clearly my jquery has been loaded properly), and call methods when things are clicked (so clearly my jquery has been loaded properly), but the second that i try to force a click, the call just does not go through.

Can anybody explain what is happening, or a way that i can get around it?

(i can not recreate this issue, because the problem clearly has to do with injecting the js in an extension)

this is the best i can do for recreation:

//I have tried all of these separately 
console.log($("#this_is_an_id"))  //This returns the correct element

$("#this_is_an_id").click()       //This does not work at all

$("#this_is_an_id").trigger("click") //I have also tried this without success

$("#this_is_an_id").click(function(){ console.log("stuff") }) //This works fine.

Really, at this point, i am assuming it is not my fault, but something that is wrong with the browser’s method of injecting script. I am sorta looking for really hackey ways to fix this, i also tried eval('$("#this_is_an_id").trigger("click")'). Does anybody have any other suggestions?

Answer 1

I finally found a very excellent answer/work around to this issue here:
Trigger events from Firefox browser extension?

From user cms:

First of all, for click events, you need to create an event object with type MouseEvents, not HTMLEvents, and use event.initMouseEvent instead of event.initEvent.

To access the document of the current tab of Firefox from a XUL overlay, you can use the content.document property, but since you already have access to the DOM element you want to click, you can use the Node.ownerDocument property, which will refer to the top-level document object for this node.

I have made a simple function to simulate MouseEvents:

function triggerMouseEvent(element, eventName, userOptions) {
  var options = { // defaults
    clientX: 0, clientY: 0, button: 0,
    ctrlKey: false, altKey: false, shiftKey: false,
    metaKey: false, bubbles: true, cancelable: true
     // create event object:
  }, event = element.ownerDocument.createEvent("MouseEvents");

  if (!/^(?:click|mouse(?:down|up|over|move|out))$/.test(eventName)) {
    throw new Error("Only MouseEvents supported");
  }

  if (typeof userOptions != 'undefined'){ // set the userOptions
    for (var prop in userOptions) {
      if (userOptions.hasOwnProperty(prop))
        options[prop] = userOptions[prop];
    }
  }
  // initialize the event object
  event.initMouseEvent(eventName, options.bubbles, options.cancelable,
                       element.ownerDocument.defaultView,  options.button,
                       options.clientX, options.clientY, options.clientX,
                       options.clientY, options.ctrlKey, options.altKey,
                       options.shiftKey, options.metaKey, options.button,
                       element);
  // dispatch!
  element.dispatchEvent(event);
}

Usage:
triggerMouseEvent(element, ‘click’);

Check a test usage here.

You can pass also an object as the third argument, if you want to change the values of the event object properties.

Thank you so much for this answer. O_O