how to edit a js object/function

Question

Hi i am using an api but i should make a patch for it

Songapi.prototype.goPlaySong=Songapi.prototype.goPlaySong.toString().replace('["universal","emi","warner"]) !== -1','false');

doesn't work also tried

Songapi.prototype.goPlaySong=Function(Songapi.prototype.goPlaySong.toString().replace('["universal","emi","warner"]) !== -1','false'));

or

Songapi.prototype.goPlaySong=eval(Songapi.prototype.goPlaySong.toString().replace('["universal","emi","warner"]) !== -1','false'));

still couldn't do it any idea?

• Virus721: I'm not sure you can edit functions just like that. You could maybe store their code into a string, replace, and then eval the string, and finally set it as the function.
• Virus721: He wants to replace a test in a parsed function by an hard coded false boolean.
• gen_Eric: @Virus721: Oh! Thanks. I didn't see how that was working.
• vladkras: It seems to me you don't even understand what you are doing. You cannot just replace something there

Answer 1

DEMO

SongApi is a constructor a.k.a a class.

function inherits(child, parent) {
 function temp() {};
 temp.prototype = parent.prototype;
 child.prototype = new temp();
 child.prototype.constructor = child;
};
var CustomizedApi = function() {
 SongApi.call(this);
};
inherits(CustomizedApi, Songapi);
// or use Object.create for inheritance.
CustomizedApi.prototype = Object.create(SongApi.prototype);
/**
 * @override
 */
CustomizedApi.prototype.goPlaySong = function() {
 // override with whatever you want.
};
var api = new CustomizedApi;
api.goPlaySong();

Answer 2

Try :

eval('var code = ' + Songapi.prototype.goPlaySong.toString().replace('["universal","emi","warner"]) !== -1','false'));
Songapi.prototype.goPlaySong = code;

But this is absolute dirtiness.

Answer 3

var newgoPlaySong=Songapi.prototype.goPlaySong.toString().replace('$.inArray(response.provider,["universal","emi","warner"]) !== -1','false');
eval('Songapi.prototype.goPlaySong = '+gecicigoPlaySong+';');

it worked thanks