Sunday, April 8, 2012

Access parent"s parent from javascript object

Somthing like

var life= {

users : {

guys : function(){ this.SOMTHING.mameAndDestroy(this.girls); },

girls : function(){ this.SOMTHING.kiss(this.boys); },


mameAndDestroy : function(group){ },

kiss : function(group){ }


this.SOMTHING is what I imagine the format is, but it might not be. What will step back up to the parent of an object?

Source: Tips4all


  1. In this case, you could use life to reference the parent object. Or you could store a reference to life in the users object. There can't be a fixed parent available to you in the language, because users is just a reference to an object, and there could be other references...

    var death = { residents : life.users };
    life.users.smallFurryCreaturesFromAlphaCentauri = { exist : function() {} };
    // death.residents.smallFurryCreaturesFromAlphaCentauri now exists
    // - because life.users references the same object as death.residents!

    You might find it helpful to use something like this:

    function addChild(ob, childName, childOb)
    ob[childName] = childOb;
    childOb.parent = ob;

    var life= {
    mameAndDestroy : function(group){ },
    kiss : function(group){ }

    addChild(life, 'users', {
    guys : function(){ this.parent.mameAndDestroy(this.girls); },
    girls : function(){ this.parent.kiss(this.boys); },

    // life.users.parent now exists and points to life

  2. I simply added in first function

    parentThis = this;

    and use parentThis in subfunction. Why? Because in JavaScript, objects are soft. A new member can be added to a soft object by simple assignment (not like ie. Java where classical objects are hard. The only way to add a new member to a hard object is to create a new class) More on this here:

    And also at the end you don't have to kill or destroy the object. Why I found here:

    Hope this helps

  3. If I'm reading your question correctly, objects in general are agnostic about where they are contained. They don't know who their parents are. To find that information, you have to parse the parent data structure. The DOM has ways of doing this for us when you're talking about element objects in a document, but it looks like you're talking about vanilla objects.

  4. Here you go:

    var life={
    guys:function(){ life.mameAndDestroy(life.users.girls); },
    girls:function(){ life.kiss(life.users.guys); }
    mameAndDestroy : function(group){
    kiss : function(group){
    //could call group() here, but would result in infinite loop


    Also, make sure you don't have a comma after the "girls" definition. This will cause the script to crash in IE (any time you have a comma after the last item in an array in IE it dies).

    See it run