Pass customdata through to scatter calcdata

src/traces/scatter/arrays_to_calcdata.js

@@ -16,6 +16,7 @@ var Lib = require('../../lib');
 module.exports = function arraysToCalcdata(cd, trace) {
 
     Lib.mergeArray(trace.text, cd, 'tx');
+    Lib.mergeArray(trace.customdata, cd, 'data');
     Lib.mergeArray(trace.textposition, cd, 'tp');
     if(trace.textfont) {
         Lib.mergeArray(trace.textfont.size, cd, 'ts');

src/traces/scatter/attributes.js

@@ -56,6 +56,10 @@ module.exports = {
             'where `y0` is the starting coordinate and `dy` the step.'
         ].join(' ')
     },
+    customdata: {
+        valType: 'data_array',
+        description: 'Assigns extra data to each scatter point DOM element'
+    },
     dy: {
         valType: 'number',
         dflt: 1,

src/traces/scatter/defaults.js

@@ -36,6 +36,7 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
         return;
     }
 
+    coerce('customdata');
     coerce('text');
     coerce('mode', defaultMode);
     coerce('ids');

src/traces/scatter/plot.js

@@ -428,9 +428,14 @@ function plotOne(gd, idx, plotinfo, cdscatter, cdscatterAll, element, transition
         }
 
         join.each(function(d) {
-            var sel = transition(d3.select(this));
+            var el = d3.select(this);
+            var sel = transition(el);
             Drawing.translatePoint(d, sel, xa, ya);
             Drawing.singlePointStyle(d, sel, trace);
+
+            if(trace.customdata) {
+                el.classed('plotly-customdata', d.data !== null && d.data !== undefined);
+            }
         });
 
         if(hasTransition) {

src/traces/scatter/style.js

@@ -24,10 +24,14 @@ module.exports = function style(gd) {
 
     s.selectAll('g.points')
         .each(function(d) {
-            d3.select(this).selectAll('path.point')
-                .call(Drawing.pointStyle, d.trace || d[0].trace);
-            d3.select(this).selectAll('text')
-                .call(Drawing.textPointStyle, d.trace || d[0].trace);
+            var el = d3.select(this);
+            var pts = el.selectAll('path.point');
+            var trace = d.trace || d[0].trace;
+
+            pts.call(Drawing.pointStyle, trace);
+
+            el.selectAll('text')
+                .call(Drawing.textPointStyle, trace);
         });
 
     s.selectAll('g.trace path.js-line')

test/jasmine/tests/calcdata_test.js

@@ -862,4 +862,18 @@ describe('calculated data and points', function() {
             });
         });
     });
+
+    describe('customdata', function() {
+        it('should pass customdata to the calcdata points', function() {
+            Plotly.plot(gd, [{
+                x: [0, 1, 3],
+                y: [4, 5, 7],
+                customdata: ['a', 'b', {foo: 'bar'}]
+            }], {});
+
+            expect(gd.calcdata[0][0]).toEqual(jasmine.objectContaining({data: 'a'}));
+            expect(gd.calcdata[0][1]).toEqual(jasmine.objectContaining({data: 'b'}));
+            expect(gd.calcdata[0][2]).toEqual(jasmine.objectContaining({data: {foo: 'bar'}}));
+        });
+    });
 });

test/jasmine/tests/scatter_test.js

@@ -1,8 +1,14 @@
+var d3 = require('d3');
 var Scatter = require('@src/traces/scatter');
 var makeBubbleSizeFn = require('@src/traces/scatter/make_bubble_size_func');
 var linePoints = require('@src/traces/scatter/line_points');
 var Lib = require('@src/lib');
 
+var Plotly = require('@lib/index');
+var createGraphDiv = require('../assets/create_graph_div');
+var destroyGraphDiv = require('../assets/destroy_graph_div');
+var fail = require('../assets/fail_test');
+
 describe('Test scatter', function() {
     'use strict';
 
@@ -326,3 +332,43 @@ describe('Test scatter', function() {
     });
 
 });
+
+describe('end-to-end scatter tests', function() {
+    var gd;
+
+    beforeEach(function() {
+        gd = createGraphDiv();
+    });
+
+    afterEach(destroyGraphDiv);
+
+    it('should add a plotly-customdata class to points with custom data', function(done) {
+        Plotly.plot(gd, [{
+            x: [1, 2, 3, 4, 5, 6, 7],
+            y: [2, 3, 4, 5, 6, 7, 8],
+            customdata: [null, undefined, 0, false, {foo: 'bar'}, 'a']
+        }]).then(function() {
+            var points = d3.selectAll('g.scatterlayer').selectAll('.point');
+
+            // Rather than just duplicating the logic, let's be explicit about
+            // what's expected. Specifially, only null and undefined (the default)
+            // do *not* add the class.
+            var expected = [false, false, true, true, true, true, false];
+
+            points.each(function(cd, i) {
+                expect(d3.select(this).classed('plotly-customdata')).toBe(expected[i]);
+            });
+
+            return Plotly.animate(gd, [{
+                data: [{customdata: []}]
+            }], {frame: {redraw: false, duration: 0}});
+        }).then(function() {
+            var points = d3.selectAll('g.scatterlayer').selectAll('.point');
+
+            points.each(function() {
+                expect(d3.select(this).classed('plotly-customdata')).toBe(false);
+            });
+
+        }).catch(fail).then(done);
+    });
+});