reduction job, chart duplicates

src/components/ChartView.vue

@@ -17,6 +17,10 @@ export default {
     yaxis: {
       type:     Array,
       required: true
+    },
+    remove_duplicates: {
+      type:    Boolean,
+      default: false
     }
   },
   computed: {
@@ -28,10 +32,23 @@ export default {
           data:            [],
           yAxisID:         index,
           borderColor:     y.color,
-          backgroundColor: y.fill
+          backgroundColor: y.fill,
+          spanGaps:        true
         };
-        for (const data of this.data)
-          res.data.push (resolve_data (data, y.field));
+        let last = null;
+        for (let i = 0; i < this.data.length; i++) {
+          const data = this.data[i];
+          const val = resolve_data (data, y.field);
+          if (
+            !this.remove_duplicates
+            || last !== val
+            || this.data.length - 1 === i
+          )
+            res.data.push (val);
+          else
+            res.data.push (null);
+          last = val;
+        }
         return res;
       });
       return { datasets, labels };