util: move GeoJSON coords / type logic in own module

- to be reuse in 'scattergeo'

Author: etpinard

src/lib/geojson_utils.js

@@ -0,0 +1,130 @@
+/**
+* Copyright 2012-2016, 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';
+
+/**
+ * Convert calcTrace to GeoJSON 'MultiLineString' coordinate arrays
+ *
+ * @param {object} calcTrace
+ *  gd.calcdata item.
+ *  Note that calcTrace[i].lonlat is assumed to be defined
+ *
+ * @return {array}
+ *  return line coords array (or array of arrays)
+ *
+ */
+exports.calcTraceToLineCoords = function(calcTrace) {
+    var trace = calcTrace[0].trace,
+        connectgaps = trace.connectgaps;
+
+    var coords = [],
+        lineString = [];
+
+    for(var i = 0; i < calcTrace.length; i++) {
+        var calcPt = calcTrace[i];
+
+        lineString.push(calcPt.lonlat);
+
+        if(!connectgaps && calcPt.gapAfter && lineString.length > 0) {
+            coords.push(lineString);
+            lineString = [];
+        }
+    }
+
+    coords.push(lineString);
+
+    return coords;
+};
+
+
+/**
+ * Make line ('LineString' or 'MultiLineString') GeoJSON
+ *
+ * @param {array} coords
+ *  results form calcTraceToLineCoords
+ * @param {object} trace
+ *  (optional) full trace object to be added on to output
+ *
+ * @return {object} out
+ *  GeoJSON object
+ *
+ */
+exports.makeLine = function(coords, trace) {
+    var out = {};
+
+    if(coords.length === 1) {
+        out = {
+            type: 'LineString',
+            coordinates: coords[0]
+        };
+    }
+    else {
+        out = {
+            type: 'MultiLineString',
+            coordinates: coords
+        };
+    }
+
+    if(trace) out.trace = trace;
+
+    return out;
+};
+
+/**
+ * Make polygon ('Polygon' or 'MultiPolygon') GeoJSON
+ *
+ * @param {array} coords
+ *  results form calcTraceToLineCoords
+ * @param {object} trace
+ *  (optional) full trace object to be added on to output
+ *
+ * @return {object} out
+ *  GeoJSON object
+ */
+exports.makePolygon = function(coords, trace) {
+    var out = {};
+
+    if(coords.length === 1) {
+        out = {
+            type: 'Polygon',
+            coordinates: coords
+        };
+    }
+    else {
+        var _coords = new Array(coords.length);
+
+        for(var i = 0; i < coords.length; i++) {
+            _coords[i] = [coords[i]];
+        }
+
+        out = {
+            type: 'MultiPolygon',
+            coordinates: _coords
+        };
+    }
+
+    if(trace) out.trace = trace;
+
+    return out;
+};
+
+/**
+ * Make blank GeoJSON
+ *
+ * @return {object}
+ *  Blank GeoJSON object
+ *
+ */
+exports.makeBlank = function() {
+    return {
+        type: 'Point',
+        coordinates: []
+    };
+};

src/traces/scattermapbox/convert.js

@@ -10,6 +10,8 @@
 'use strict';
 
 var Lib = require('../../lib');
+var geoJsonUtils = require('../../lib/geojson_utils');
+
 var subTypes = require('../scatter/subtypes');
 var convertTextOpts = require('../../plots/mapbox/convert_text_opts');
 
@@ -46,11 +48,11 @@ module.exports = function convert(calcTrace) {
     // fill layer and line layer use the same coords
     var coords;
     if(hasFill || hasLines) {
-        coords = getCoords(calcTrace);
+        coords = geoJsonUtils.calcTraceToLineCoords(calcTrace);
     }
 
     if(hasFill) {
-        fill.geojson = makeFillGeoJSON(calcTrace, coords);
+        fill.geojson = geoJsonUtils.makePolygon(coords);
         fill.layout.visibility = 'visible';
 
         Lib.extendFlat(fill.paint, {
@@ -59,7 +61,7 @@ module.exports = function convert(calcTrace) {
     }
 
     if(hasLines) {
-        line.geojson = makeLineGeoJSON(calcTrace, coords);
+        line.geojson = geoJsonUtils.makeLine(coords);
         line.layout.visibility = 'visible';
 
         Lib.extendFlat(line.paint, {
@@ -133,45 +135,12 @@ module.exports = function convert(calcTrace) {
 
 function initContainer() {
     return {
-        geojson: makeBlankGeoJSON(),
+        geojson: geoJsonUtils.makeBlank(),
         layout: { visibility: 'none' },
         paint: {}
     };
 }
 
-function makeBlankGeoJSON() {
-    return {
-        type: 'Point',
-        coordinates: []
-    };
-}
-
-function makeFillGeoJSON(_, coords) {
-    if(coords.length === 1) {
-        return {
-            type: 'Polygon',
-            coordinates: coords
-        };
-    }
-
-    var _coords = new Array(coords.length);
-    for(var i = 0; i < coords.length; i++) {
-        _coords[i] = [coords[i]];
-    }
-
-    return {
-        type: 'MultiPolygon',
-        coordinates: _coords
-    };
-}
-
-function makeLineGeoJSON(_, coords) {
-    return {
-        type: 'MultiLineString',
-        coordinates: coords
-    };
-}
-
 // N.B. `hash` is mutated here
 //
 // The `hash` object contains mapping between values
@@ -323,29 +292,6 @@ function calcCircleRadius(trace, hash) {
     return out;
 }
 
-function getCoords(calcTrace) {
-    var trace = calcTrace[0].trace,
-        connectgaps = trace.connectgaps;
-
-    var coords = [],
-        lineString = [];
-
-    for(var i = 0; i < calcTrace.length; i++) {
-        var calcPt = calcTrace[i];
-
-        lineString.push(calcPt.lonlat);
-
-        if(!connectgaps && calcPt.gapAfter && lineString.length > 0) {
-            coords.push(lineString);
-            lineString = [];
-        }
-    }
-
-    coords.push(lineString);
-
-    return coords;
-}
-
 function getFillFunc(attr) {
     if(Array.isArray(attr)) {
         return function(v) { return v; };