Add hoverongaps to heatmap and contour for suppressing hovers on missing data

src/traces/contour/attributes.js

@@ -38,7 +38,7 @@ module.exports = extendFlat({
     ytype: heatmapAttrs.ytype,
     zhoverformat: heatmapAttrs.zhoverformat,
     hovertemplate: heatmapAttrs.hovertemplate,
-
+    hoverongaps: heatmapAttrs.hoverongaps,
     connectgaps: extendFlat({}, heatmapAttrs.connectgaps, {
         description: [
             'Determines whether or not gaps',

src/traces/contour/defaults.js

@@ -35,6 +35,7 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     coerce('text');
     coerce('hovertext');
     coerce('hovertemplate');
+    coerce('hoverongaps');
 
     var isConstraint = (coerce('contours.type') === 'constraint');
     coerce('connectgaps', Lib.isArray1D(traceOut.z));

src/traces/heatmap/attributes.js

@@ -79,6 +79,17 @@ module.exports = extendFlat({
             'Picks a smoothing algorithm use to smooth `z` data.'
         ].join(' ')
     },
+    hoverongaps: {
+        valType: 'boolean',
+        dflt: true,
+        role: 'style',
+        editType: 'none',
+        description: [
+            'Determines whether or not gaps',
+            '(i.e. {nan} or missing values)',
+            'in the `z` data have hover labels associated with them.'
+        ].join(' ')
+    },
     connectgaps: {
         valType: 'boolean',
         role: 'info',

src/traces/heatmap/defaults.js

@@ -34,6 +34,7 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
 
     handleStyleDefaults(traceIn, traceOut, coerce, layout);
 
+    coerce('hoverongaps');
     coerce('connectgaps', Lib.isArray1D(traceOut.z) && (traceOut.zsmooth !== false));
 
     colorscaleDefaults(traceIn, traceOut, layout, coerce, {prefix: '', cLetter: 'z'});

src/traces/heatmap/hover.js

@@ -91,6 +91,8 @@ module.exports = function hoverPoints(pointData, xval, yval, hovermode, hoverLay
     var zVal = z[ny][nx];
     if(zmask && !zmask[ny][nx]) zVal = undefined;
 
+    if(zVal === undefined && !trace.hoverongaps) return;
+
     var text;
     if(Array.isArray(cd0.hovertext) && Array.isArray(cd0.hovertext[ny])) {
         text = cd0.hovertext[ny][nx];

test/jasmine/tests/contour_test.js

@@ -66,7 +66,7 @@ describe('contour defaults', function() {
 
     it('should default connectgaps to false if `z` is not a one dimensional array', function() {
         traceIn = {
-            type: 'heatmap',
+            type: 'contour',
             z: [[0, null], [1, 2]]
         };
 
@@ -76,7 +76,7 @@ describe('contour defaults', function() {
 
     it('should default connectgaps to true if `z` is a one dimensional array', function() {
         traceIn = {
-            type: 'heatmap',
+            type: 'contour',
             x: [0, 1, 0, 1],
             y: [0, 0, 1, 1],
             z: [0, null, 1, 2]
@@ -591,3 +591,61 @@ describe('contour plotting and editing', function() {
         .then(done);
     });
 });
+
+describe('contour hover', function() {
+    'use strict';
+
+    var gd;
+
+    function _hover(gd, xval, yval) {
+        var fullLayout = gd._fullLayout;
+        var calcData = gd.calcdata;
+        var hoverData = [];
+
+        for(var i = 0; i < calcData.length; i++) {
+            var pointData = {
+                index: false,
+                distance: 20,
+                cd: calcData[i],
+                trace: calcData[i][0].trace,
+                xa: fullLayout.xaxis,
+                ya: fullLayout.yaxis
+            };
+
+            var hoverPoint = Contour.hoverPoints(pointData, xval, yval);
+            if(hoverPoint) hoverData.push(hoverPoint[0]);
+        }
+
+        return hoverData;
+    }
+
+    describe('missing data', function() {
+        beforeAll(function(done) {
+            gd = createGraphDiv();
+
+            Plotly.plot(gd, {
+                data: [{
+                    type: 'contour',
+                    x: [10, 11, 10, 11],
+                    y: [100, 100, 101, 101],
+                    z: [null, 1, 2, 3],
+                    connectgaps: false,
+                    hoverongaps: false
+                }]
+            }).then(done);
+        });
+        afterAll(destroyGraphDiv);
+
+        it('should not display hover on missing data and hoverongaps is disabled', function() {
+            var pt = _hover(gd, 10, 100)[0];
+
+            var hoverData;
+            gd.on('plotly_hover', function(data) {
+                hoverData = data;
+            });
+
+            expect(hoverData).toEqual(undefined);
+            expect(pt).toEqual(undefined);
+        });
+    });
+});

test/jasmine/tests/heatmap_test.js

@@ -976,4 +976,34 @@ describe('heatmap hover', function() {
             .then(done);
         });
     });
+
+    describe('missing data', function() {
+        beforeAll(function(done) {
+            gd = createGraphDiv();
+
+            Plotly.plot(gd, {
+                data: [{
+                    type: 'heatmap',
+                    x: [10, 11, 10, 11],
+                    y: [100, 100, 101, 101],
+                    z: [null, 1, 2, 3],
+                    connectgaps: false,
+                    hoverongaps: false
+                }]
+            }).then(done);
+        });
+        afterAll(destroyGraphDiv);
+
+        it('should not display hover on missing data and hoverongaps is disabled', function() {
+            var pt = _hover(gd, 10, 100)[0];
+
+            var hoverData;
+            gd.on('plotly_hover', function(data) {
+                hoverData = data;
+            });
+
+            expect(hoverData).toEqual(undefined);
+            expect(pt).toEqual(undefined);
+        });
+    });
 });