return a listener+path from firebase._addObservers

Hi Eddy, i want to propose you some little changes so we can use the removeEventListener

first we return an object with path and listener from the _addObservers

firebase._addObservers = function(to, updateCallback) {
   var listener = new com.google.firebase.database.ChildEventListener({
   [...]
   return listenerPlusPathObj;
}

and we resolve the promise with it

firebase.addChildEventListener = function (updateCallback, path) {
   [...]
   var listenerPlusPathObj = firebase._addObservers(firebase.instance.child(path), updateCallback);
   resolve(listenerPlusPathObj);
   [...]
}

we return the same obj here

firebase.addValueEventListener = function (updateCallback, path) {
   [...]
   resolve(listenerPlusPathObj);
   [...]
}

and then again we resolve the promise with the obj

firebase.query = function (updateCallback, path, options) {
   [...]
   else {
        var listenerPlusPathObj = firebase._addObservers(query, updateCallback);
        resolve(listenerPlusPathObj);
    }
   [...]
}

of course in the query we don’t have to think about the singleEvent option because that listener should die after the first call.

I imagine the listenerPlusPathObj like

{
  "listener": listener,
  "path": path
}

in this way we can call removeEventListener(obj.listener, obj.path);

now we have all the tools to use the firebase.removeEventListener = function (listener, path) which is also very useful for my porting of geofire as a garbage collector for all the unused listeners. what do you think? any problems or better ideas?

[EddyVerbruggen]

Btw that NativeScript-Android issue has been fixed and the kind folks at NativeScript will ship the fix with the next release. So we made the framework better with this feature as well 👍

[andrew19881123]

Hi, that’s a great work! I’ve reviewed the code just now (not tested yet) and just one thing came to mind: because the query() returns 1 or 4 listeners depending on the platform and one goal of this plugin is to create a layer of abstraction above the two, in this situation a developer has to understand the problem and use properly the two in the correct case, like removeEventListeners against the query() function (that’s not obvious). So my idea is to hide from the public api the removeEventListener and just give the developer the option to use removeEventListeners which takes an array of listeners (even an array with one element). In this way it’s not confusing, because you can choose only between one option, and you keep the same functionality…