Address review comments; part of #207

Author: pkra

lib/main.js

@@ -60,6 +60,7 @@ var defaults = {
   svg: false,                     // return svg output?
   svgNode: false,              // DOM element for SVG output?
   timeout: 10 * 1000,             // 10 second timeout before restarting MathJax
+  speakText: true,               // add spoken annotations to svg output
 };
 
 //
@@ -513,6 +514,10 @@ function AddError(message,nopush) {
 function GetMML(result) {
   if (!data.mml && !data.mmlNode) return;
   var jax = MathJax.Hub.getAllJax()[0];
+  if (data.speakText && !jax.root.alttext){
+    jax.root.alttext = result.speakText;
+    jax.root.attrNames.push("alttext");
+  }
   try {
     if (data.mml) result.mml = jax.root.toMathML('',jax);
     if (data.mmlNode) result.mmlNode = jsdom(result.mml).body.firstChild;
@@ -523,20 +528,16 @@ function GetMML(result) {
 }
 
 //
-//  Creates dummy speech string and updates the MathML to include it, if needed
+//  Creates speech string and updates the MathML to include it, if needed
 //
 function GetSpeech(result) {
+  if (!data.speakText) return;
   result.speakText = "Equation";
   if (data.format !== "MathML") result.speakText = data.math;
-  if (!data.mml) return;
-  var jax = MathJax.Hub.getAllJax()[0];
-  if (jax.root.alttext) result.speakText = jax.root.alttext;
-  else jax.root.alttext = result.speakText;
-  var attrNames = jax.root.attrNames;
-  if (attrNames && attrNames.indexOf("alttext") === -1) {
-    attrNames.push("alttext");
+  else {
+    var jax = MathJax.Hub.getAllJax()[0];
+    if (jax.root.alttext) result.speakText = jax.root.alttext;
   }
-  result.mml = jax.root.toMathML('',jax);
 }
 
 //
@@ -547,11 +548,11 @@ function GetHTML(result) {
   var jax = MathJax.Hub.getAllJax()[0]; if (!jax) return;
   var script = jax.SourceElement(), html = script.previousSibling;
 
-  // add dummy speech text if there isn't one
-  for (var i=0, m=html.childNodes.length; i < m; i++)
-    html.childNodes[i].setAttribute("aria-hidden",true);
-  if (!html.getAttribute("aria-label")) {
-    html.setAttribute("aria-label",result.speakText);
+  // add speech text if there isn't one
+  if (data.speakText){
+    for (var i=0, m=html.childNodes.length; i < m; i++)
+      html.childNodes[i].setAttribute("aria-hidden",true);
+    if (!html.getAttribute("aria-label")) html.setAttribute("aria-label",result.speakText);
   }
   // remove automatically generated IDs
   var ids = html.querySelectorAll('[id^="MJXc-Node-"]');
@@ -587,17 +588,18 @@ function GetSVG(result) {
   //
   //  Add the speech text and mark the SVG appropriately
   //
-  for (var i=0, m=svg.childNodes.length; i < m; i++)
-    svg.childNodes[i].setAttribute("aria-hidden",true);
-  // Note: if aria-label exists, getSpeech preserved it in speakText
-  // remove aria-label since labelled-by desc is preferred
-  svg.removeAttribute("aria-label");
-  ID++; var id = "MathJax-SVG-"+ID;
-  svg.setAttribute("aria-labelledby",id+"-Desc");
-  var node = MathJax.HTML.Element("desc",{id:id+"-Desc"},[result.speakText]);
+  if (data.speakText){
+    for (var i=0, m=svg.childNodes.length; i < m; i++)
+      svg.childNodes[i].setAttribute("aria-hidden",true);
+    // Note: if aria-label exists, getSpeech preserved it in speakText
+    // remove aria-label since labelled-by desc is preferred
+    svg.removeAttribute("aria-label");
+  }
+  ID++; var id = "MathJax-SVG-"+ID+"-Desc";
+  svg.setAttribute("aria-labelledby",id);
+  var node = MathJax.HTML.Element("desc",{id:id},[result.speakText]);
   svg.insertBefore(node,svg.firstChild);
 
-
   if (data.svg){
     //
     //  SVG data is modified to add linebreaks for readability,
@@ -675,8 +677,8 @@ function StartQueue() {
     $$(SetRenderer,renderer),
     $$("Typeset",HUB),
     $$(TypesetDone,result),
-    $$(GetMML,result),
     $$(GetSpeech,result),
+    $$(GetMML,result),
     $$(GetHTML,result),
     $$(RerenderSVG,result),
     $$(GetSVG,result),
@@ -737,9 +739,6 @@ function ReturnResult(result) {
   if (errors.length) {
     result.errors = errors;
   }
-  if (!data.mml) {
-    delete result.mml;
-  }
   var state = data.state;
   if (state) {
     var AMS = MathJax.Extension["TeX/AMSmath"];