Question

I have this piece of code:

var myObj = function () {    this.complex = function (text) { /* long piece of code */ }    this.parse(text) {      return text.replace(/valid_pattern/gi, function ($1) { return this.complex($1); } );    } } 

Of course calling this.complex($1) won’t do the trick, because I’m in the scope of the anonymous function. I can’t re-scope the anonymous function using .call(this) statement either, because in th ta case I would lose the parameters passed to the function by String.replace.

So far I’m using the concrete instance of the object. This is my solution:

var instance = new myObj; var myObj = function () {    this.complex = function (text) { /* long piece of code */ }    this.parse(text) {      return text.replace(/valid_pattern/gi, function ($1) { return instance.complex($1); } );    } } 

So far it’s sufficient to my needs, but I’m wondering if there is any universal solution to this problem. The only idea that has worked for me so far is this:

function ($1) { return (new myObj).complex($1); } 

… which suffers from serious performance issues. Any ideas would be greatly appreciated.

— D.

P. S. Sorry about my English, it’s not my first language.

Answer 1

Maybe try:

var myObj = function () {    this.complex = function (text) { /* long piece of code */ }    this.parse(text) {      var that = this;      return text.replace(/valid_pattern/gi, function ($1) { return that.complex($1); } );    } } 

It is one of the most useful tricks 🙂

UPDATE: The trick is not mine, I learned it (as most of things I know about Javascript) from: Douglas Crockford