Merge pull request #2977 from plotly/polar-hole

Add `polar.hole`

src/plots/polar/constants.js

@@ -22,10 +22,10 @@ module.exports = {
         'angular-grid',
         'radial-grid',
         'frontplot',
-        'angular-axis',
-        'radial-axis',
         'angular-line',
-        'radial-line'
+        'radial-line',
+        'angular-axis',
+        'radial-axis'
     ],
 
     radialDragBoxSize: 50,

src/plots/polar/layout_attributes.js

@@ -112,16 +112,6 @@ var radialAxisAttrs = {
 
     hoverformat: axesAttrs.hoverformat,
 
-    // More attributes:
-
-    // We'll need some attribute that determines the span
-    // to draw donut-like charts
-    // e.g. https://github.com/matplotlib/matplotlib/issues/4217
-    //
-    // maybe something like 'span' or 'hole' (like pie, but pie set it in data coords?)
-    // span: {},
-    // hole: 1
-
     editType: 'calc'
 };
 
@@ -256,6 +246,17 @@ module.exports = {
             'with *0* corresponding to rightmost limit of the polar subplot.'
         ].join(' ')
     },
+    hole: {
+        valType: 'number',
+        min: 0,
+        max: 1,
+        dflt: 0,
+        editType: 'plot',
+        role: 'info',
+        description: [
+            'Sets the fraction of the radius to cut out of the polar subplot.'
+        ].join(' ')
+    },
 
     bgcolor: {
         valType: 'color',

src/plots/polar/layout_defaults.js

@@ -30,6 +30,7 @@ function handleDefaults(contIn, contOut, coerce, opts) {
     opts.bgColor = Color.combine(bgColor, opts.paper_bgcolor);
 
     var sector = coerce('sector');
+    coerce('hole');
 
     // could optimize, subplotData is not always needed!
     var subplotData = getSubplotData(opts.fullData, constants.name, opts.id);