Adding functionality to Intl.NumberFormat

Question

I'm trying to add functionality to the format function but there is something wrong with my code:

Object.defineProperty(Intl.NumberFormat.prototype, "format", { value: function(){
     //your logic here
     let orig = Intl.NumberFormat.prototype
     console.log(orig);// does not remember the original proto
}, configurable: true } );

What am I missing?

What do you mean "original proto"? What are you expecting? – Niet the Dark Absol Jul 03 '17 at 09:19 — Niet the Dark Absol, Jul 03 '17 at 09:19

Jonas Wilms · Accepted Answer · 2017-07-03T16:25:01.853

1

You basically catch the property itself. You want to get the original one so before it is overriden, and you may store its subobject references too through copying them:

{
   let orig = Object.assign({}, Intl.NumberFormat.prototype);
   Object.defineProperty(Intl.NumberFormat.prototype, "format", { value: function(){
      //your logic here     
     console.log(orig);// does remember the original proto
   }, configurable: true } );
}

edited Jul 03 '17 at 16:25

answered Jul 03 '17 at 09:33

Jonas Wilms

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Thanks for the reply, however it seems that the orig.format is being re-written to the new declaration – Roni Gadot Jul 03 '17 at 10:39
1

@roni gadot right in that case you need to keep a reference,ive edited – Jonas Wilms Jul 03 '17 at 16:24

Adding functionality to Intl.NumberFormat

1 Answers1