Is it possible to organise methods on an object's prototype into namespaces?

Question

I'm trying to achieve a specific syntax pattern in JavaScript. Essentially, the requirement is to extend the prototypes of native JavaScript objects with new methods, and to organise those methods into namespaces. The result I'm looking for can be summed up as:

String.prototype.foo = {
    bar: function() { return this.toUpperCase(); } //Fails because "this" is foo, not it's parent string
};
'test'.foo.bar(); //should return 'TEST'

I am aware there are other ways to achieve similar results but I really would prefer the syntax above is possible - although I'm about 80% sure that it's not.

I've tried a dozen different ways of constructing this but I can't find any way of reaching the string as "this" inside bar(). I believe the problem is that because foo is an object and has no executable code, there is no way for the compiler to pass the owner "this" to it and from there down to the child method, but I wondered if some obscure technique for walking the parent chain exists that I don't know about? The next best thing might be 'test'.foo().bar(), which I haven't tried, but sounds more likely to work.

possible duplicate of [Organize prototype javascript while perserving object reference and inheritance](http://stackoverflow.com/q/15884096/1048572) — Bergi, May 29 '16 at 22:10

score 4 · Accepted Answer · answered Mar 01 '14 at 01:35

4

Sure, here you go:

Object.defineProperty(String.prototype,"foo", {
   get: function(){ 
        return { 
            bar: function(){ return this.toUpperCase() }.bind(this)
        }
   },
   enumerable: false, // don't show in for.. in loop
   configuratble: true,
});

"hello".foo.bar(); // "HELLO"

A couple of things to notice:

defineProperty for defining a getter
Function::bind for fixing the this value.

answered Mar 01 '14 at 01:35

Benjamin Gruenbaum

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Note that the long term solution will probably be ES7 protocols, but I have to admit I kind of like this getter idea in the meanwhile. – Benjamin Gruenbaum Mar 01 '14 at 01:40
Perfect. Hadn't occurred to me to try a getter - this is exactly the solution I was looking for, thanks! – wwarby Mar 01 '14 at 08:48
@wwarby glad I could help - do keep me updated if you figure out how to do something cool with this! – Benjamin Gruenbaum Mar 01 '14 at 14:05
this is very nice! – Stato Machino May 07 '17 at 21:57

score 0 · Answer 2 · answered Mar 01 '14 at 01:16

0

While this answer makes your "namespace" a function rather than an object, this should work:

String.prototype.foo = function(){
     var self = this;
     return {
         bar: function() { return self.toUpperCase(); }
     };
}

'test'.foo().bar()

answered Mar 01 '14 at 01:16

Fisch

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score 0 · Answer 3 · answered Mar 01 '14 at 01:23

Hi here is the solution with function

String.prototype.foo = function(){
    var that = this;
    return{
        bar:function(){
            return that.toUpperCase()
        }
    }
}

'test'.foo().bar();

I think the solution with object does not exist. Note that 1 object can exists in many "parents" so how to decide which one is the one you want

Is it possible to organise methods on an object's prototype into namespaces?

3 Answers3

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