working, cascading filter transform points

Author: monfera

src/transforms/filter.js

@@ -170,6 +170,8 @@ exports.calcTransform = function(gd, trace, opts) {
     var d2c = Axes.getDataToCoordFunc(gd, trace, target, targetArray);
     var filterFunc = getFilterFunc(opts, d2c, targetCalendar);
     var originalArrays = {};
+    var indexToPoints = {};
+    var index = 0;
 
     function forAllAttrs(fn, index) {
         for(var j = 0; j < arrayAttrs.length; j++) {
@@ -204,10 +206,33 @@ exports.calcTransform = function(gd, trace, opts) {
     forAllAttrs(initFn);
 
     // loop through filter array, fill trace arrays if passed
-    for(var i = 0; i < len; i++) {
-        var passed = filterFunc(targetArray[i]);
-        if(passed) forAllAttrs(fillFn, i);
+
+    var prevTransforms = trace.transforms.filter(function(tr) {return tr.indexToPoints;});
+
+    if(prevTransforms.length > 0) {
+
+        var prevTransform = prevTransforms[prevTransforms.length - 1];
+        var prevIndexToPoints = prevTransform.indexToPoints;
+
+        for(var i = 0; i < len; i++) {
+            var passed = filterFunc(targetArray[i]);
+            if(passed) {
+                forAllAttrs(fillFn, i);
+                indexToPoints[index++] = prevIndexToPoints[i];
+            }
+        }
+    } else {
+        for(var i = 0; i < len; i++) {
+            var passed = filterFunc(targetArray[i]);
+            if(passed) {
+                forAllAttrs(fillFn, i);
+                indexToPoints[index++] = [i];
+            }
+        }
     }
+
+    opts.indexToPoints = indexToPoints;
+    console.log(indexToPoints)
 };
 
 function getFilterFunc(opts, d2c, targetCalendar) {

test/jasmine/tests/transform_filter_test.js

@@ -62,7 +62,7 @@ describe('filter transforms defaults:', function() {
         traceIn = {
             x: [1, 2, 3],
             transforms: [{
-                type: 'filter',
+                type: 'filter'
             }, {
                 type: 'filter',
                 target: 0
@@ -143,6 +143,7 @@ describe('filter transforms calc:', function() {
         expect(out[0].x).toEqual([0, 1]);
         expect(out[0].y).toEqual([1, 2]);
         expect(out[0].z).toEqual(['2016-10-21', '2016-12-02']);
+        expect(out[0].transforms[0].indexToPoints).toEqual({0: [3], 1 :[4]});
     });
 
     it('should use the calendar from the target attribute if target is a string', function() {
@@ -261,13 +262,14 @@ describe('filter transforms calc:', function() {
         expect(out[0].x).toEqual([-2, 2, 3]);
         expect(out[0].y).toEqual([3, 3, 1]);
         expect(out[0].marker.color).toEqual([0.3, 0.3, 0.4]);
+        expect(out[0].transforms[0].indexToPoints).toEqual({0: [2], 1 :[5], 2: [6]});
     });
 
     it('filters should handle array on base trace attributes', function() {
         var out = _transform([Lib.extendDeep({}, base, {
             hoverinfo: ['x', 'y', 'text', 'name', 'none', 'skip', 'all'],
             hoverlabel: {
-                bgcolor: ['red', 'green', 'blue', 'black', 'yellow', 'cyan', 'pink'],
+                bgcolor: ['red', 'green', 'blue', 'black', 'yellow', 'cyan', 'pink']
             },
             transforms: [{
                 type: 'filter',
@@ -314,6 +316,8 @@ describe('filter transforms calc:', function() {
 
         expect(out[0].x).toEqual([1, 2]);
         expect(out[0].y).toEqual([2, 3]);
+        expect(out[0].transforms[0].indexToPoints).toEqual({0: [4], 1 :[5], 2: [6]});
+        expect(out[0].transforms[1].indexToPoints).toEqual({0: [4], 1 :[5]});
     });
 
     it('filters should chain as AND (case 2)', function() {
@@ -339,6 +343,8 @@ describe('filter transforms calc:', function() {
 
         expect(out[0].x).toEqual([3]);
         expect(out[0].y).toEqual([1]);
+        expect(out[0].transforms[0].indexToPoints).toEqual({0: [4], 1 :[5], 2: [6]});
+        expect(out[0].transforms[2].indexToPoints).toEqual({0: [6]});
     });
 
     it('should preserve gaps in data when `preservegaps` is turned on', function() {