Merge pull request #44 from gormanb/master

Check that options.zoom exists before reading options.zoom.drag in beforeInit

Author: etimberg

Chart.Zoom.js

@@ -302,7 +302,7 @@ var zoomPlugin = {
 		var options = chartInstance.options;
 		var panThreshold = helpers.getValueOrDefault(options.pan ? options.pan.threshold : undefined, zoomNS.defaults.pan.threshold);
 
-		if (options.zoom.drag) {
+		if (options.zoom && options.zoom.drag) {
 			// Only want to zoom horizontal axis
 			options.zoom.mode = 'x';
 

Chart.Zoom.min.js

@@ -290,7 +290,7 @@ var zoomPlugin = {
 		var options = chartInstance.options;
 		var panThreshold = helpers.getValueOrDefault(options.pan ? options.pan.threshold : undefined, zoomNS.defaults.pan.threshold);
 
-		if (options.zoom.drag) {
+		if (options.zoom && options.zoom.drag) {
 			// Only want to zoom horizontal axis
 			options.zoom.mode = 'x';