Canvas event listener not working

Question

I am using fabric.js

Canvas event listener is not triggered while there is a change in canvas

    var canvas = canvas(300,100);

Attaching event listener

  canvas.on({
    'mouse:up' : modifiedHandler,
    'mouse:down' : modifiedHandler,
    'object:modified' : modifiedHandler
  });

This event listener is not triggered while there is change in canvas

  var modifiedHandler = function (event) {

    console.log('trigger') // Not triggered
  };

This function returns canvas

  function canvas(width, height) {
    this.width = width;
    this.height = height;
    this.object = object();

    function object() {
      return new fabric.Canvas('id', {
        selection: false,
        height: this.height,
        width: this.width
      });
    }
    return this.object;
  }

Adding the fiddle reference here

Answer 1

Declare modifiedHandler first before you use it.

 var modifiedHandler = function (event) {
     alert('trigger');  // trigger
  };
  canvas.on({
    'mouse:up' : modifiedHandler,
    'mouse:down' : modifiedHandler,
    'object:modified' : modifiedHandler
  })