Update fontURL, support for reconfiguration

README.md

@@ -83,7 +83,7 @@ The `config` method is used to set _global_ configuration options. Its default o
   displayErrors:   true, // determines whether error messages are shown on the console
   undefinedCharError: false, // determines whether "unknown characters" (i.e., no glyph in the configured fonts) are saved in the error array
   extensions: '', // a convenience option to add MathJax extensions
-  fontURL: 'https://cdn.mathjax.org/mathjax/latest/fonts/HTML-CSS', // for webfont urls in the CSS for HTML output
+  fontURL: 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/fonts/HTML-CSS', // for webfont urls in the CSS for HTML output
   MathJax: { } // standard MathJax configuration options, see https://docs.mathjax.org for more detail.
 }
 ```

lib/main.js

@@ -38,7 +38,7 @@ var displayMessages = false;      // don't log Message.Set() calls
 var displayErrors = true;         // show error messages on the console
 var undefinedChar = false;        // unknown characters are not saved in the error array
 var extensions = '';              // no additional extensions used
-var fontURL = 'https://cdn.mathjax.org/mathjax/latest/fonts/HTML-CSS';  // location of web fonts for CHTML
+var fontURL = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/fonts/HTML-CSS';  // location of web fonts for CHTML
 
 var defaults = {
   ex: 6,                          // ex-size in pixels
@@ -865,6 +865,12 @@ exports.config = function (config) {
   if (config.displayErrors != null)      {displayErrors   = config.displayErrors}
   if (config.undefinedCharError != null) {undefinedChar   = config.undefinedCharError}
   if (config.extensions != null)         {extensions      = config.extensions}
-  if (config.fontURL != null)            {fontURL         = config.fontURL}
+  if (config.fontURL != null)            { 
+    if(CHTMLSTYLES && fontURL !== config.fontURL) {
+      var expression = new RegExp(fontURL, "g");
+      CHTMLSTYLES = CHTMLSTYLES.replace(expression,config.fontURL)
+    }
+    fontURL = config.fontURL;
+  }
   if (config.MathJax) {MathJaxConfig = config.MathJax}
 }

test/base-config-fonturl.js

@@ -0,0 +1,30 @@
+var tape = require('tape');
+var mjAPI = require("../lib/main.js");
+
+tape('basic configuration: check fontURL', function (t) {
+    t.plan(2);
+
+    var tex = 'a';
+    mjAPI.typeset({
+        math: tex,
+        format: "TeX",
+        css: true
+    }, function (result, data) {
+        t.ok(result.css.indexOf('https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/fonts/HTML-CSS') > -1, 'Default fontURL');
+    });
+    // reconfigure
+    mjAPI.typeset({
+        math: ''
+    }, function(){
+        mjAPI.config({
+            fontURL: 'https://example.com'
+        });
+    })
+    mjAPI.typeset({
+        math: tex,
+        format: "TeX",
+        css: true,
+    }, function (result, data) {
+        t.ok(result.css.indexOf('https://example.com') > -1, 'Configuring fontURL');
+    });
+});