Make object notation usable for polarArea and radar

docs/general/data-structures.md

@@ -69,7 +69,7 @@ options: {
 }
 ```
 
-When using the pie/doughnut chart type, the `parsing` object should have a `key` item that points to the value to look at. In this example, the doughnut chart will show two items with values 1500 and 500.
+When using the pie/doughnut or polarArea chart type, the `parsing` object should have a `key` item that points to the value to look at. In this example, the doughnut chart will show two items with values 1500 and 500.
 
 ```javascript
 type: 'doughnut',

src/controllers/controller.polarArea.js

@@ -1,6 +1,5 @@
 import DatasetController from '../core/core.datasetController';
-import {toRadians, PI} from '../helpers/index';
-import {formatNumber} from '../helpers/helpers.intl';
+import {toRadians, PI, formatNumber, isObject, resolveObjectKey} from '../helpers/index';
 
 export default class PolarAreaController extends DatasetController {
 
@@ -23,6 +22,23 @@ export default class PolarAreaController extends DatasetController {
     };
   }
 
+  parseObjectData(meta, data, start, count) {
+    const {iScale} = meta;
+    const {key = 'key'} = this._parsing;
+    const parsed = new Array(count);
+    let i, ilen, index, item;
+
+    for (i = 0, ilen = count; i < ilen; ++i) {
+      index = i + start;
+      item = data[index];
+      parsed[i] = {
+        r: iScale.parse(resolveObjectKey(item, key), index)
+      };
+    }
+
+    return parsed;
+  }
+
   update(mode) {
     const arcs = this._cachedMeta.data;
 
@@ -59,6 +75,7 @@ export default class PolarAreaController extends DatasetController {
     const datasetStartAngle = scale.getIndexAngle(0) - 0.5 * PI;
     let angle = datasetStartAngle;
     let i;
+    const {key = 'key'} = this._parsing;
 
     const defaultAngle = 360 / this.countVisibleElements();
 
@@ -67,9 +84,10 @@ export default class PolarAreaController extends DatasetController {
     }
     for (i = start; i < start + count; i++) {
       const arc = arcs[i];
+      const dataPoint = isObject(dataset.data[i]) ? resolveObjectKey(dataset.data[i], key) : dataset.data[i];
       let startAngle = angle;
       let endAngle = angle + this._computeAngle(i, mode, defaultAngle);
-      let outerRadius = chart.getDataVisibility(i) ? scale.getDistanceFromCenterForValue(dataset.data[i]) : 0;
+      let outerRadius = chart.getDataVisibility(i) ? scale.getDistanceFromCenterForValue(dataPoint) : 0;
       angle = endAngle;
 
       if (reset) {
@@ -98,10 +116,11 @@ export default class PolarAreaController extends DatasetController {
   countVisibleElements() {
     const dataset = this.getDataset();
     const meta = this._cachedMeta;
+    const {key = 'key'} = this._parsing;
     let count = 0;
 
     meta.data.forEach((element, index) => {
-      if (!isNaN(dataset.data[index]) && this.chart.getDataVisibility(index)) {
+      if ((!isNaN(dataset.data[index]) || (!isNaN(resolveObjectKey(dataset.data[index], key)))) && this.chart.getDataVisibility(index)) {
         count++;
       }
     });

test/fixtures/controller.polarArea/parse-object-data.json

@@ -0,0 +1,27 @@
+{
+  "config": {
+    "type": "polarArea",
+    "data": {
+      "datasets": [
+        {
+          "data": [{"id": "Sales", "nested": {"value": 10}}, {"id": "Purchases", "nested": {"value": 20}}],
+          "backgroundColor": ["red", "blue"]
+        }
+      ]
+    },
+    "options": {
+      "responsive": false,
+      "plugins": {
+        "legend": false
+      },
+      "parsing": {
+        "key": "nested.value"
+      },
+      "scales": {
+        "r": {
+          "display": false
+        }
+      }
+    }
+  }
+}