CODEWITHSUNDEEP
javascriptclassdynamic
J D
J D

Reputation: 174

Dynamic function call to a class's function, using settimeout


I have a class like structure in javascript, Im attempting to invoke a sibling function using a passed in function name.
This is difficulty to explain so let me show you an example of what im trying to accomplish..

function windowFactory(){
    this.init = function(functionName,args[]){
        SetTimeout(functionName(args),2000)
    }
    this.func1 = function(var1){
        alert(var1);
    }
    this.func2 = function(var1, var2){
        alert(var1+var2);
    }
}
var win1 = new windowFactory();
win1.init("func1","hello");
var win2 = new windowFactory();
win2.init("func2","world","!");

Please note that this is only a demo function, syntax errors / typos included.
Now i had this working using a dreaded Eval when it was outside the class... 

eval(funcName+"('"+darray[1]+"','"+darray[2]+"')");

It just required it being outside the Class and passed in dummy values for parameters

Upvotes: 1

Views: 915

Answers (1)

Betamos
Betamos

Reputation: 28787

Something like this should do the trick:

var windowFactory = function() {
  var self = this;
  this.init = function(functionName){
      var args = Array.prototype.slice.call(arguments, 1);
      setTimeout(function() {
          self[functionName].apply(self, args);
      }, 2000);
  };
  this.func1 = function(var1){
      alert(var1);
  };
  this.func2 = function(var1, var2){
      alert(var1+var2);
  };
};
var win1 = new windowFactory();
win1.init("func1","hello");
var win2 = new windowFactory();
win2.init("func2","world","!");

Note the custom self reference var self = this;. This is used because when the timed out function is called, the this object will be window (at least in a web browser).

Another clarification: To address a specific object property in JavaScript you can do in the following ways:

object.property; // Or
object['property']; // When you have a string literal, like in your example

Upvotes: 1

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