use extractOpts in extractScale

... and add makeColorScaleFuncFromTrace wrapper to DRY things up
    a little bit.

Author: etpinard

Diff for: src/components/colorscale/helpers.js

@@ -104,6 +104,7 @@ function extractOpts(cont) {
 
     return out;
 }
+
 /**
  * Extract colorscale into numeric domain and color range.
  *
@@ -112,24 +113,19 @@ function extractOpts(cont) {
  *  - cmin/zmin {number}
  *  - cmax/zmax {number}
  *  - reversescale {boolean}
- * @param {object} opts
- *  - cLetter {string} 'c' (for cmin/cmax) or 'z' (for zmin/zmax)
  *
  * @return {object}
  *  - domain {array}
  *  - range {array}
  */
-function extractScale(cont, opts) {
-    var cLetter = opts.cLetter;
-
-    var scl = cont.reversescale ?
-        flipScale(cont.colorscale) :
-        cont.colorscale;
+function extractScale(cont) {
+    var cOpts = extractOpts(cont);
+    var cmin = cOpts.min;
+    var cmax = cOpts.max;
 
-    // minimum color value (used to clamp scale)
-    var cmin = cont[cLetter + 'min'];
-    // maximum color value (used to clamp scale)
-    var cmax = cont[cLetter + 'max'];
+    var scl = cOpts.reversescale ?
+        flipScale(cOpts.colorscale) :
+        cOpts.colorscale;
 
     var N = scl.length;
     var domain = new Array(N);
@@ -141,10 +137,7 @@ function extractScale(cont, opts) {
         range[i] = si[1];
     }
 
-    return {
-        domain: domain,
-        range: range
-    };
+    return {domain: domain, range: range};
 }
 
 function flipScale(scl) {
@@ -220,6 +213,10 @@ function makeColorScaleFunc(specs, opts) {
     return sclFunc;
 }
 
+function makeColorScaleFuncFromTrace(trace, opts) {
+    return makeColorScaleFunc(extractScale(trace), opts);
+}
+
 function colorArray2rbga(colorArray) {
     var colorObj = {
         r: colorArray[0],
@@ -236,5 +233,6 @@ module.exports = {
     extractOpts: extractOpts,
     extractScale: extractScale,
     flipScale: flipScale,
-    makeColorScaleFunc: makeColorScaleFunc
+    makeColorScaleFunc: makeColorScaleFunc,
+    makeColorScaleFuncFromTrace: makeColorScaleFuncFromTrace
 };

Diff for: src/components/colorscale/index.js

@@ -33,7 +33,8 @@ module.exports = {
 
     hasColorscale: helpers.hasColorscale,
     extractOpts: helpers.extractOpts,
-    flipScale: helpers.flipScale,
     extractScale: helpers.extractScale,
-    makeColorScaleFunc: helpers.makeColorScaleFunc
+    flipScale: helpers.flipScale,
+    makeColorScaleFunc: helpers.makeColorScaleFunc,
+    makeColorScaleFuncFromTrace: helpers.makeColorScaleFuncFromTrace
 };

Diff for: src/lib/gl_format_color.js

@@ -47,9 +47,7 @@ function formatColor(containerIn, opacityIn, len) {
     var sclFunc, getColor, getOpacity, colori, opacityi;
 
     if(containerIn.colorscale !== undefined) {
-        sclFunc = Colorscale.makeColorScaleFunc(
-            Colorscale.extractScale(containerIn, {cLetter: 'c'})
-        );
+        sclFunc = Colorscale.makeColorScaleFuncFromTrace(containerIn);
     } else {
         sclFunc = validateColor;
     }

Diff for: src/traces/choropleth/style.js

@@ -24,9 +24,7 @@ function styleTrace(gd, calcTrace) {
     var marker = trace.marker || {};
     var markerLine = marker.line || {};
 
-    var sclFunc = Colorscale.makeColorScaleFunc(
-        Colorscale.extractScale(trace, {cLetter: 'z'})
-    );
+    var sclFunc = Colorscale.makeColorScaleFuncFromTrace(trace);
 
     locs.each(function(d) {
         d3.select(this)

Diff for: src/traces/heatmap/plot.js

@@ -14,7 +14,7 @@ var tinycolor = require('tinycolor2');
 
 var Registry = require('../../registry');
 var Lib = require('../../lib');
-var Colorscale = require('../../components/colorscale');
+var makeColorScaleFuncFromTrace = require('../../components/colorscale').makeColorScaleFuncFromTrace;
 var xmlnsNamespaces = require('../../constants/xmlns_namespaces');
 
 module.exports = function(gd, plotinfo, cdheatmaps, heatmapLayer) {
@@ -140,10 +140,7 @@ module.exports = function(gd, plotinfo, cdheatmaps, heatmapLayer) {
         canvas.height = canvasH;
         var context = canvas.getContext('2d');
 
-        var sclFunc = Colorscale.makeColorScaleFunc(
-            Colorscale.extractScale(trace, {cLetter: 'z'}),
-            { noNumericCheck: true, returnArray: true }
-        );
+        var sclFunc = makeColorScaleFuncFromTrace(trace, {noNumericCheck: true, returnArray: true});
 
         // map brick boundaries to image pixels
         var xpx,

Diff for: src/traces/scattermapbox/convert.js

@@ -157,9 +157,7 @@ function makeCircleOpts(calcTrace) {
     var colorFn;
     if(arrayColor) {
         if(Colorscale.hasColorscale(trace, 'marker')) {
-            colorFn = Colorscale.makeColorScaleFunc(
-                 Colorscale.extractScale(marker, {cLetter: 'c'})
-             );
+            colorFn = Colorscale.makeColorScaleFuncFromTrace(marker);
         } else {
             colorFn = Lib.identity;
         }

Diff for: test/jasmine/tests/colorscale_test.js

@@ -647,11 +647,11 @@ describe('Test colorscale:', function() {
         it('should constrain color array values between cmin and cmax', function() {
             var trace = {
                 colorscale: scale,
-                pmin: 2,
-                pmax: 3
+                cmin: 2,
+                cmax: 3
             };
 
-            var specs = Colorscale.extractScale(trace, {cLetter: 'p'});
+            var specs = Colorscale.extractScale(trace);
             var sclFunc = Colorscale.makeColorScaleFunc(specs);
 
             var color1 = sclFunc(1);
@@ -669,11 +669,11 @@ describe('Test colorscale:', function() {
             var trace = {
                 colorscale: scale,
                 reversescale: true,
-                pmin: 2,
-                pmax: 3
+                zmin: 2,
+                zmax: 3
             };
 
-            var specs = Colorscale.extractScale(trace, {cLetter: 'p'});
+            var specs = Colorscale.extractScale(trace);
             var sclFunc = Colorscale.makeColorScaleFunc(specs);
 
             var color1 = sclFunc(1);