Question

I have a chart object, with methods draw and update. See this (non-working) fiddle.

draw does a lot of things with the object’s properties, and at the end, draws a chart. At this point, I am able to define an update function, since all the data that was processed by draw is there. But then I can’t call update from outside the scope.

How do I define the update method as a completely separate method so I can call it from outside the object, but have it be able to reference data within the draw method?

Update: I’ve posted some semi-pseudo code.

Answer 1

like this perhaps:

function MyChart(x,y){

   this.draw = function(){
      console.log('draw chart using variables x:' + x + ' y:' + y);

      return {
          update: function(){
               console.log('update chart using variables x:' + x + ' y:' + y);
          }
      }
   }
}

usage:

 var chart = new MyChart(123,987);
 var drawResult = chart.draw();
 drawResult.update();

Live example: http://jsfiddle.net/c9TeU/