♻️ a few snapshot helpers

Author: etpinard

src/plot_api/to_image.js

@@ -74,8 +74,6 @@ var attrs = {
     }
 };
 
-var IMAGE_URL_PREFIX = /^data:image\/\w+;base64,/;
-
 /** Plotly.toImage
  *
  * @param {object | string | HTML div} gd
@@ -179,7 +177,7 @@ function toImage(gd, opts) {
                 if(imageDataOnly) {
                     return resolve(svg);
                 } else {
-                    return resolve('data:image/svg+xml,' + encodeURIComponent(svg));
+                    return resolve(helpers.encodeSVG(svg));
                 }
             }
 
@@ -206,7 +204,7 @@ function toImage(gd, opts) {
 
     function urlToImageData(url) {
         if(imageDataOnly) {
-            return url.replace(IMAGE_URL_PREFIX, '');
+            return url.replace(helpers.IMAGE_URL_PREFIX, '');
         } else {
             return url;
         }

src/snapshot/download.js

@@ -8,9 +8,12 @@
 
 'use strict';
 
-var toImage = require('../plot_api/to_image');
 var Lib = require('../lib');
+
+var toImage = require('../plot_api/to_image');
+
 var fileSaver = require('./filesaver');
+var helpers = require('./helpers');
 
 /** Plotly.downloadImage
  *
@@ -41,7 +44,7 @@ function downloadImage(gd, opts) {
         //   does not allow toDataURL
         //   svg format will work though
         if(Lib.isIE() && opts.format !== 'svg') {
-            reject(new Error('Sorry IE does not support downloading from canvas. Try {format:\'svg\'} instead.'));
+            reject(new Error(helpers.MSG_IE_BAD_FORMAT));
         }
 
         if(_gd) _gd._snapshotInProgress = true;

src/snapshot/helpers.js

@@ -31,3 +31,11 @@ exports.getRedrawFunc = function(gd) {
         }
     };
 };
+
+exports.encodeSVG = function(svg) {
+    return 'data:image/svg+xml,' + encodeURIComponent(svg);
+};
+
+exports.IMAGE_URL_PREFIX = /^data:image\/\w+;base64,/;
+
+exports.MSG_IE_BAD_FORMAT = 'Sorry IE does not support downloading from canvas. Try {format:\'svg\'} instead.';

src/snapshot/svgtoimg.js

@@ -11,6 +11,8 @@
 var Lib = require('../lib');
 var EventEmitter = require('events').EventEmitter;
 
+var helpers = require('./helpers');
+
 function svgToImg(opts) {
     var ev = opts.emitter || new EventEmitter();
 
@@ -21,7 +23,7 @@ function svgToImg(opts) {
 
         // IE only support svg
         if(Lib.isIE() && format !== 'svg') {
-            var ieSvgError = new Error('Sorry IE does not support downloading from canvas. Try {format:\'svg\'} instead.');
+            var ieSvgError = new Error(helpers.MSG_IE_BAD_FORMAT);
             reject(ieSvgError);
             // eventually remove the ev
             //  in favor of promises
@@ -45,7 +47,7 @@ function svgToImg(opts) {
         // for Safari support, eliminate createObjectURL
         //  this decision could cause problems if content
         //  is not restricted to svg
-        var url = 'data:image/svg+xml,' + encodeURIComponent(svg);
+        var url = helpers.encodeSVG(svg);
 
         canvas.width = w1;
         canvas.height = h1;