[main] enable css output without html output

Resolves #292

Author: pkra

lib/main.js

@@ -563,6 +563,7 @@ function GetSpeech(result) {
 //  Create HTML and CSS output, if requested
 //
 function GetHTML(result) {
+  if (data.css) result.css = CHTMLSTYLES;
   if (!data.html && !data.htmlNode) return;
   var jax = MathJax.Hub.getAllJax()[0]; if (!jax) return;
   var script = jax.SourceElement(), html = script.previousSibling;
@@ -591,7 +592,6 @@ function GetHTML(result) {
   }
   if (data.html) result.html = html.outerHTML;
   if (data.htmlNode) result.htmlNode = html;
-  if (data.css) result.css = CHTMLSTYLES;
 }
 
 //
@@ -684,7 +684,7 @@ function StartQueue() {
   //
   GetState(data.state);
 
-  var renderer = ( (data.html || data.htmlNode) ? "CommonHTML" : "SVG");
+  var renderer = ( (data.html || data.htmlNode || data.css) ? "CommonHTML" : "SVG");
 
   //
   //  Set up a timeout timer to restart MathJax if it runs too long,
@@ -784,7 +784,7 @@ function SetRenderer(renderer) {
 }
 
 function RerenderSVG(result) {
-  if ((data.html || data.htmlNode ) && (data.svg || data.svgNode)) {
+  if ((data.html || data.htmlNode || data.css) && (data.svg || data.svgNode)) {
     timer = setTimeout(RestartMathJax,data.timeout);
     var queue = MathJax.Callback.Queue(), $$ = window.Array;
     return queue.Push(

test/css.js

@@ -0,0 +1,23 @@
+var tape = require('tape');
+var mjAPI = require("../lib/main.js");
+
+tape('CSS output', function(t) {
+    t.plan(2);
+    mjAPI.start();
+    var tex = 'x';
+    mjAPI.typeset({
+        math: tex,
+        format: "TeX",
+        css: true
+    }, function(data) {
+        t.ok(data.css, 'css output while no other output');
+    });
+    mjAPI.typeset({
+        math: tex,
+        format: "TeX",
+        css: true,
+        svg: true
+    }, function(data) {
+        t.ok(data.css, 'css output with SVG output');
+    });
+});