added service to provide canvas all over

src/app/directives/guilloche.directive.ts

@@ -8,18 +8,33 @@ import * as Drag from 'd3-drag';
 import { Config } from './../models/config.model';
 import { Point } from './../models/point.model';
 import { Param } from './../models/param.model';
+import { CanvasService } from './../services/canvas.service';
 
 @Directive({
   selector: '[guilloche]'
 })
 export class GuillocheDirective implements OnChanges {
 
+  private canvas: any;
+
   @Input() graph: Graph;
 
-  constructor() {
+  constructor(
+    private canvasService: CanvasService
+  ) {
   }
 
   ngOnChanges(changes: SimpleChanges) {
-    console.log('guilloche directive (changes)', changes.graph);
+    console.log('guilloche directive (changes)', changes.graph.currentValue);
+    this.selectCanvas();
+    this.drawGraph();
+  }
+
+  private drawGraph(): void {
+    console.log('guilloche directive(drawGraph)', this.graph, this.canvas);
+  }
+
+  private selectCanvas(): void {
+    this.canvas = Selection.select(this.canvasService.get);
   }
 }