implemented Base64 attribute on DonutChart

Author: tieniber

src/ChartJS/widgets/Core.js

@@ -667,6 +667,21 @@ define([
 
         _animationComplete: function () {
             logger.debug(this.id + "._animationComplete");
+			if(this.base64Attr) {
+				var ctx = this.canvasNode.getContext('2d');
+				var imgData=ctx.getImageData(0,0,this.canvasNode.width,this.canvasNode.height);
+				var data=imgData.data;
+				for(var i=0;i<data.length;i+=4){
+					if(data[i+3]<255){
+						data[i]=255;
+						data[i+1]=255;
+						data[i+2]=255;
+						data[i+3]=255;
+					}
+				}
+				ctx.putImageData(imgData,0,0);
+				this._mxObj.set(this.base64Attr, this.canvasNode.toDataURL("image/jpeg"));
+			}
             // Use this.canvasNode.toDataURL() to get an image
         }
 

src/ChartJS/widgets/DoughnutChart/DoughnutChart.xml

@@ -205,6 +205,14 @@
                 <description>Microflow to invoke when chart canvas is clicked. This Microflow will pass the Dataset object 'Data set entity'</description>
                 <returnType type="Void"></returnType>
             </property>
+			<property key="base64Attr" type="attribute" required="false">
+				<caption>Base 64 Attribute</caption>
+				<category>Behavior</category>
+				<description>The attribute to store the base64 encoding of the chart when rendered.</description>
+				<attributeTypes>
+					<attributeType name="String"/>
+				</attributeTypes>
+			</property>
             <!-- Settings -->
             <property key="responsive" type="boolean" required="true" defaultValue="true">
                 <caption>Responsive</caption>

src/ChartJS/widgets/DoughnutChart/widget/DoughnutChart.js

@@ -140,7 +140,9 @@ define([
             }));
 
             // Set the con
-            html.set(this._numberNode, this._data.object.get(this.numberInside).toString());
+			if(this.numberInside) {
+				html.set(this._numberNode, this._data.object.get(this.numberInside).toString());
+			}
 
             // Add class to determain chart type
             this._addChartClass("chartjs-doughnut-chart");