optional events in options

.gitignore

@@ -1 +1,2 @@
 node_modules
+.vscode

src/index.ts

@@ -540,7 +540,9 @@ abstract class ChartwerkPod<T extends TimeSerie, O extends Options> {
           .attr('height', 15)
           .html(`<form><input type=checkbox ${isChecked? 'checked' : ''} /></form>`)
           .on('click', () => {
-            this.options.eventsCallbacks.onLegendClick(idx);
+            if(this.options.eventsCallbacks !== undefined && this.options.eventsCallbacks.onLegendClick !== undefined) {
+              this.options.eventsCallbacks.onLegendClick(idx);
+            }
           });
 
         legendRow.append('text')
@@ -551,7 +553,9 @@ abstract class ChartwerkPod<T extends TimeSerie, O extends Options> {
           .style('fill', this.getSerieColor(idx))
           .text(this.series[idx].target)
           .on('click', () => {
-            this.options.eventsCallbacks.onLegendLabelClick(idx);
+            if(this.options.eventsCallbacks !== undefined && this.options.eventsCallbacks.onLegendLabelClick !== undefined) {
+              this.options.eventsCallbacks.onLegendLabelClick(idx);
+            }
           });
       }
     }

src/types.ts

@@ -13,17 +13,17 @@ export type Options = {
   margin?: Margin;
   confidence?: number;
   eventsCallbacks?: {
-    zoomIn: (range: AxisRange[]) => void,
-    panning: (event: { ranges: AxisRange[], d3Event: any }) => void,
-    panningEnd: (range: AxisRange[]) => void,
-    zoomOut: (centers: {x: number, y: number}) => void,
-    mouseMove: (evt: any) => void,
-    mouseOut: () => void,
-    onLegendClick: (idx: number) => void,
-    onLegendLabelClick: (idx: number) => void,
-    contextMenu: (evt: any) => void, // the same name as in d3.events
-    sharedCrosshairMove: (event: any) => void,
-    renderEnd: () => void,
+    zoomIn?: (range: AxisRange[]) => void,
+    panning?: (event: { ranges: AxisRange[], d3Event: any }) => void,
+    panningEnd?: (range: AxisRange[]) => void,
+    zoomOut?: (centers: {x: number, y: number}) => void,
+    mouseMove?: (evt: any) => void,
+    mouseOut?: () => void,
+    onLegendClick?: (idx: number) => void,
+    onLegendLabelClick?: (idx: number) => void,
+    contextMenu?: (evt: any) => void, // the same name as in d3.events
+    sharedCrosshairMove?: (event: any) => void,
+    renderEnd?: () => void,
   };
   axis?: {
     x?: AxisOption,