9 Replies Latest reply on Sep 28, 2015 3:48 PM by Qwertyfly...

    Add event handler as/via prototype?

    Silly-V Adobe Community Professional

      I would like to try and increase my javascript knowledge here.

      So, here is what I have got so far, and I would like to make it better. I saw that if you click on the 1 pixel in the border of a dropdown list in CC ScriptUI, it will have the undesired effect of selecting "null", which crashed some of my scripts. Therefore I have made this "prototype" that selects the first item, should someone trigger the effect of selecting null by inadvertently clicking on the border of the dropdownlist.


      DropDownList.prototype.selectWell = function(){

        //CC will let you select null

        this.addEventListener('change', function(){

          if(this.selection == null){

            this.selection = this.items[0];





      The way it would work is like this:


      var d = window.add("dropdownlist", undefined, ["Item 1","Item 2"]);



      Okay, this works, but then you gotta write "d.selectWell();" after every dropdown.

      Would it be possible to write such code that every new instance of a dropdownlist already comes with this event listener added?



      In browser javascript, they have querySelector(element) to add one listener to every element of the desired kind. I am not sure there is such available in ScriptUI.

      I suppose it would be possible to do mass listener assignments via recursive function, but would need to be repeated in windows where new dropdowns are added dynamically.
      Also, I could make my own constructor, call it SuperDropDownList and in that constructor add all the necessary listeners and use it to add any dropdown that I want to have the custom functionality in.

      However, if this could be done with a simple "DropDownList.prototype", I would like to learn how to do so!