chartjs v2 - bartop controller that displays value at top of bar chart using y axis formating

bartop.js

(function() {

	"use strict";

	var root = this,
		Chart = root.Chart,
		helpers = Chart.helpers;

	Chart.defaults.bartop = helpers.extendDeep({},Chart.defaults.bar);

	Chart.controllers.bartop = function(chart, datasetIndex) {
		this.initialize.call(this, chart, datasetIndex);
	};
	
	helpers.extend(Chart.controllers.bartop.prototype,Chart.controllers.bar.prototype,{
		draw: function(ease) {
			
			var easingDecimal = ease || 1;

			helpers.each(this.getDataset().metaData, function(rectangle, index) {
				rectangle.transition(easingDecimal).draw();
			}, this);

			var ctx=this.chart.chart.ctx;
			var ticks=this.chart.scales["y-axis-0"]; // is this a safe way to get the yaxis?
			var options=ticks.options;
			var labelFont = helpers.fontString(options.ticks.fontSize, options.ticks.fontStyle, options.ticks.fontFamily);
			ctx.font = labelFont;
			ctx.fillStyle = options.ticks.fontColor;

			helpers.each(this.getDataset().metaData, function(rectangle, index) {

				var value=this.getDataset().data[index];
	
				var vm = rectangle._view;
				var top = vm.base - (vm.base - vm.y);
				var text=options.ticks.callback(value, index, ticks);

				ctx.save();
				ctx.font = labelFont;
				ctx.textAlign = "center";
				ctx.textBaseline = "bottom" ;
				ctx.fillText(text, vm.x, top);
				ctx.restore();
			}, this);

		},
	});


}).call(this);