[mj-single] remove support for PNG generation

Author: pkra

lib/mj-single.js

@@ -2,16 +2,16 @@
  *
  *  mj-single-svg.js
  *
- *  Implements an API to MathJax in node.js so that MathJax can be
- *  used server-side to generate SVG, MathML, or images (the latter
- *  requires an external library, batik, to do the svg to png
- *  conversion).  This API converts single math expressions to SVG,
- *  will giving control over the input format, the font caching, and
- *  a number of other features.
+ *  Implements an API to MathJax in Node.js so that MathJax can be
+ *  used server-side to generate HTML+CSS, SVG, or MathML.
+ *
+ *  This API converts single math expressions while giving control
+ *  over the input format, the SVG font caching, and a number of other
+ *  features.
  *
  * ----------------------------------------------------------------------
  *
- *  Copyright (c) 2014 The MathJax Consortium
+ *  Copyright (c) 2014--2016 The MathJax Consortium
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -30,11 +30,8 @@ var http = require('http');
 var fs = require('fs');
 var path = require('path');
 var url = require('url');
-var fmt = require('util').format;
 var jsdom = require('jsdom').jsdom;
-var execFile = require('child_process').execFile;
 var speech = require('speech-rule-engine');
-var os = require('os');
 
 require('./patch/jsdom.js').patch(jsdom);  //  Fix some bugs in jsdom
 
@@ -60,9 +57,6 @@ var defaults = {
   css: false,                     // return CSS for HTML output?
   mml: false,                     // return mml output?
   svg: false,                     // return svg output?
-  img: false,                     // return img tag for remote image?
-  png: false,                     // return png image (as data: URL)?
-  dpi: 144,                       // dpi for png image
 
   speakText: false,               // add spoken annotations to svg output?
   speakRuleset: "mathspeak",      // set speech ruleset (default (chromevox rules), mathspeak)
@@ -88,12 +82,10 @@ var STATE = {
 // The MathJaxPath is normaized against file:/// so that Windows paths are correct
 //
 var MathJaxPath = url.resolve("file:///","file:"+require.resolve('mathjax/unpacked/MathJax'));
-var BatikRasterizerPath = path.resolve(__dirname,'..','batik/batik-rasterizer.jar');
 var MathJaxConfig;                   // configuration for when starting MathJax
 var MathJax;                         // filled in once MathJax is loaded
 var serverState = STATE.STOPPED;     // nothing loaded yet
 var timer;                           // used to reset MathJax if it runs too long
-var tmpfile = os.tmpdir() + "/mj-single-svg" +  process.pid;  // file name prefix to use for temp files
 
 var document, window, content, html; // the DOM elements
 
@@ -593,10 +585,10 @@ function GetHTML(result) {
 }
 
 //
-//  Create SVG output and IMG output, if requested
+//  Create SVG output, if requested
 //
 function GetSVG(result) {
-  if (!data.svg && !data.png && !data.img) return;
+  if (!data.svg) return;
   var jax = MathJax.Hub.getAllJax()[0]; if (!jax) return;
   var script = jax.SourceElement(),
       svg = script.previousSibling.getElementsByTagName("svg")[0];
@@ -623,67 +615,15 @@ function GetSVG(result) {
   var svgdata = svg.outerHTML.replace(/><([^/])/g,">\n<$1")
                              .replace(/(<\/[a-z]*>)(?=<\/)/g,"$1\n")
                              .replace(/(<(?:use|image) [^>]*)(href=)/g,' $1xlink:$2');
-  //
-  //  The file version includes the xml and DOCTYPE comments
-  //
-  var svgfile = [
-    '<?xml version="1.0" standalone="no"?>',
-    '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">',
-    svgdata
-  ].join("\n");
 
   //
   //  Add the requested data to the results
   //
-  if (data.svg) result.svg = svgdata;
-  if (data.png) result.svgfile = svgfile;
-  if (data.img) {
-    if (data.svg) result.svg = svgfile;
-    result.img = [
-      '<img src="file.svg" style="',
-      svg.style.cssText,
-      " width:",svg.getAttribute("width"),"; height:",svg.getAttribute("height"),
-      ';"',
-      (data.speakText ? ' alt="'+result.speakText+'"' : ""),
-      ' />'
-    ].join("");
-  }
-
-  //
-  //  Add metadata to the results
-  //
-  if (data.svg){
-    result.svg = svgdata;
-    result.width = svg.getAttribute("width");
-    result.height = svg.getAttribute("height");
-    result.style =  svg.style.cssText;
-  }
-
-}
+  result.svg = svgdata;
+  result.width = svg.getAttribute("width");
+  result.height = svg.getAttribute("height");
+  result.style =  svg.style.cssText;
 
-//
-//  Create the PNG file asynchronously, reporting errors.
-//
-function GetPNG(result) {
-  var svgfile = result.svgfile; delete result.svgfile;
-  if (data.png) {
-    var batikCommands = ['-jar', BatikRasterizerPath, '-dpi', data.dpi, tmpfile + '.svg'];
-    var synch = MathJax.Callback(function () {}); // for synchronization with MathJax
-    var check = function (err) {if (err) {AddError(err.message); synch(); return true}}
-    var tmpSVG = tmpfile+".svg", tmpPNG = tmpfile+".png";
-    fs.writeFile(tmpSVG,svgfile,function (err) {
-      if (check(err)) return;
-      execFile('java', batikCommands, function (err,stdout,stderr) {
-        if (check(err)) {fs.unlinkSync(tmpSVG); return}
-        fs.readFile(tmpPNG,null,function (err,buffer) {
-          result.png = "data:image/png;base64,"+(buffer||"").toString('base64');
-          fs.unlinkSync(tmpSVG); fs.unlinkSync(tmpPNG);
-          check(err); synch();
-        });
-      });
-    });
-    return synch;  // This keeps the queue from continuing until the readFile() is complete
-  }
 }
 
 /********************************************************************/
@@ -735,7 +675,7 @@ function StartQueue() {
 
   //
   //  Set up a timeout timer to restart MathJax if it runs too long,
-  //  Then push the Typeset call, the MathML, speech, SVG, and PNG calls,
+  //  Then push the Typeset call, the MathML, speech, and SVG calls,
   //  and our TypesetDone routine
   //
   timer = setTimeout(RestartMathJax,data.timeout);
@@ -749,7 +689,6 @@ function StartQueue() {
     $$(GetHTML,result),
     $$(RerenderSVG,result),
     $$(GetSVG,result),
-    $$(GetPNG,result),
     $$(ReturnResult,result)
   );
 }
@@ -836,7 +775,7 @@ function SetRenderer(renderer) {
 }
 
 function RerenderSVG(result) {
-  if (data.html && (data.svg || data.png || data.img)) {
+  if (data.html && data.svg) {
     timer = setTimeout(RestartMathJax,data.timeout);
     var queue = MathJax.Callback.Queue(), $$ = window.Array;
     return queue.Push(