add hovertemplate to splom traces

Author: etpinard

src/traces/splom/attributes.js

@@ -10,6 +10,7 @@
 
 var scatterAttrs = require('../scatter/attributes');
 var colorAttrs = require('../../components/colorscale/attributes');
+var hovertemplateAttrs = require('../../components/fx/hovertemplate_attributes');
 var scatterGlAttrs = require('../scattergl/attributes');
 var cartesianIdRegex = require('../../plots/cartesian/constants').idRegex;
 var templatedArray = require('../../plot_api/plot_template').templatedArray;
@@ -123,6 +124,7 @@ module.exports = {
             'this trace\'s (x,y) coordinates.'
         ].join(' ')
     }),
+    hovertemplate: hovertemplateAttrs(),
 
     marker: markerAttrs,
 

src/traces/splom/defaults.js

@@ -39,6 +39,7 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     }
 
     coerce('text');
+    coerce('hovertemplate');
 
     handleMarkerDefaults(traceIn, traceOut, defaultColor, layout, coerce);
 

test/jasmine/tests/splom_test.js

@@ -1360,6 +1360,18 @@ describe('Test splom hover:', function() {
         nums: 'Apr 2003',
         axis: 'Jan 2000',
         evtPts: [{x: '2000-01-01', y: '2003-04-21', pointNumber: 0}]
+    }, {
+        desc: 'with a hovertemplate',
+        patch: function(fig) {
+            fig.data.forEach(function(t) {
+                t.hovertemplate = '%{x}|%{y}<extra>pt %{pointNumber}</extra>'
+            });
+            fig.layout.hovermode = 'closest';
+            return fig;
+        },
+        nums: '2.6|7.7',
+        name: 'pt 18',
+        evtPts: [{x: 2.6, y: 7.7, pointNumber: 18, curveNumber: 2}]
     }];
 
     specs.forEach(function(s) {