fix for multibar widget

httpdocs/js/widgets/templates/multibar-chart-template.js

@@ -0,0 +1,49 @@
+import { ChartTemplate } from './default-template.js';
+
+export default class MultiBarChartTemplate extends ChartTemplate {
+
+    constructor(params) { super(params); console.log(this); }
+
+    _addGraph() {
+
+        const self = this;
+        nv.addGraph(function() {
+
+            const multibarChart = nv.models.multiBarChart();
+            multibarChart.height(self._height);
+            multibarChart.width(self._width);
+            multibarChart.stacked(true);
+
+            d3.select(`#${self._defaultOptions.domId}`)
+                .append('svg')
+                .datum(self._data)
+                .transition()
+                .duration(1000)
+                .call(multibarChart);
+
+            if (self._defaultOptions.widget.intervalTime) {
+               self._intervalId = setInterval(async function() {
+                    const newData = await self._updateData();
+                    self._data = newData.data;
+                    multibarChart.update();
+                }, self._defaultOptions.widget.intervalTime);
+            }
+
+            self._chart = multibarChart;
+
+            return multibarChart;
+        });
+    }
+
+    render() {
+
+        const container = super.render();
+        /* if I have data to show then add the graph! */
+        if (this._data.length != 0) {
+            container.setAttribute('style', `width:${this._width}px;height:${this._width}px`);
+            this._addGraph();
+        }
+        return container;
+    }
+
+}