extracting out common function

Author: monfera

src/transforms/aggregate.js

@@ -11,6 +11,7 @@
 var Axes = require('../plots/cartesian/axes');
 var Lib = require('../lib');
 var PlotSchema = require('../plot_api/plot_schema');
+var pointsAccessorFunction = require('./helpers').pointsAccessorFunction;
 var BADNUM = require('../constants/numerical').BADNUM;
 
 exports.moduleType = 'transform';
@@ -221,10 +222,7 @@ exports.calcTransform = function(gd, trace, opts) {
     var indexToPoints = {};
     var groupings = [];
 
-    var prevTransforms = trace.transforms.filter(function(tr) {return tr._indexToPoints;});
-    var originalPointsAccessor = prevTransforms.length ?
-        function(i) {return prevTransforms[prevTransforms.length - 1]._indexToPoints[i];} :
-        function(i) {return [i];};
+    var originalPointsAccessor = pointsAccessorFunction(trace.transforms, opts);
 
     for(i = 0; i < groupArray.length; i++) {
         vi = groupArray[i];
@@ -237,7 +235,7 @@ exports.calcTransform = function(gd, trace, opts) {
         }
         else {
             groupings[groupIndex].push(i);
-            indexToPoints[groupIndices[vi]] = indexToPoints[groupIndices[vi]].concat(originalPointsAccessor(i));
+            indexToPoints[groupIndices[vi]] = (indexToPoints[groupIndices[vi]] || []).concat(originalPointsAccessor(i));
         }
     }
 

src/transforms/filter.js

@@ -11,6 +11,7 @@
 var Lib = require('../lib');
 var Registry = require('../registry');
 var Axes = require('../plots/cartesian/axes');
+var pointsAccessorFunction = require('./helpers').pointsAccessorFunction;
 
 var COMPARISON_OPS = ['=', '!=', '<', '>=', '>', '<='];
 var INTERVAL_OPS = ['[]', '()', '[)', '(]', '][', ')(', '](', ')['];
@@ -205,11 +206,8 @@ exports.calcTransform = function(gd, trace, opts) {
     // copy all original array attribute values, and clear arrays in trace
     forAllAttrs(initFn);
 
-    var prevTransforms = trace.transforms.filter(function(tr) {return tr._indexToPoints;});
-    var originalPointsAccessor = prevTransforms.length ?
-        function(i) {return prevTransforms[prevTransforms.length - 1]._indexToPoints[i];} :
-        function(i) {return [i];};
-
+    var originalPointsAccessor = pointsAccessorFunction(trace.transforms, opts);
+    
     // loop through filter array, fill trace arrays if passed
     for(var i = 0; i < len; i++) {
         var passed = filterFunc(targetArray[i]);

src/transforms/helpers.js

@@ -0,0 +1,24 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+exports.pointsAccessorFunction = function(transforms, opts) {
+    var tr;
+    var prevIndexToPoints;
+    for(var i = 0; i < transforms.length; i++) {
+        tr = transforms[i];
+        if(tr === opts) break;
+        if(!tr._indexToPoints || tr.enabled === false) continue;
+        prevIndexToPoints = tr._indexToPoints;
+    }
+    var originalPointsAccessor = prevIndexToPoints ?
+        function(i) {return prevIndexToPoints[i];} :
+        function(i) {return [i];};
+    return originalPointsAccessor;
+};