Website/node_modules/mathjax-node/lib/mj-single.js

725 lines
25 KiB
JavaScript

/*********************************************************************
*
* 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.
*
* ----------------------------------------------------------------------
*
* Copyright (c) 2014 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.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
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');
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 defaults = {
ex: 6, // ex-size in pixels
width: 100, // width of container (in ex) for linebreaking and tags
useFontCache: true, // use <defs> and <use> in svg output?
useGlobalCache: false, // use common <defs> for all equations?
linebreaks: false, // do linebreaking?
equationNumbers: "none", // or "AMS" or "all"
math: "", // the math to typeset
format: "TeX", // the input format (TeX, inline-TeX, AsciiMath, or MathML)
xmlns: "mml", // the namespace to use for MathML
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)
speakStyle: "default", // set speech style (mathspeak: default, brief, sbrief)
timeout: 10 * 1000, // 10 second timeout before restarting MathJax
};
//
// The MathJax server states
//
var STATE = {
STOPPED: 1, // no DOM or MathJax available
STARTED: 2, // DOM loaded, MathJax starting up
READY: 3, // MathJax initialized and ready to process math
BUSY: 4 // MathJax currently processing math
};
//
// 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
var queue = []; // queue of typesetting requests of the form [data,callback]
var data, callback; // the current queue item
var errors = []; // errors collected durring the typesetting
var ID = 0; // id for this SVG element
//
// The delimiters used for each of the input formats
//
var delimiters = {
TeX: ["$$","$$"],
"inline-TeX": ["$","$"],
AsciiMath: ["`","`"],
MathML: ["",""]
};
/********************************************************************/
//
// Create the DOM window and set up the console wtihin it
// Add an error handler to trap unexpected errors (requires
// modifying jsdom)
// Add a <div> where we can put the math to be typeset
// and typeset math in the three formats we use (to force
// the jax to be loaded completely)
//
function GetWindow() {
document = jsdom();
html = document.firstChild;
window = document.defaultView;
window.console = console;
window.onerror = function (err,url,line) {AddError("Error: "+err)}
content = document.body.appendChild(document.createElement("div"));
content.id = "MathJax_Content";
content.innerHTML = "$x$ `x` <math><mi>x</mi></math>";
//
// Node's url.resolve() has a problem with resolving a file:// URL when
// the base URL is "about:blank", so force it to be something else (HACK)
// since jsdom 3.x sets the base to "about:blank".
//
if (document._URL === "about:blank") document._URL = "file:///blank.html";
}
//
// Set up a Mathjax configuration within the window
//
function ConfigureMathJax() {
window.MathJax = {
//
// Load all input jax and preprocessors
// Load AMS extensions and the autoload extension for TeX
// Allow $...$ delimiters and don't create previews for any preprocessor,
// Create stand-alone SVG elements with font caches by default
// (users can override that)
//
jax: ["input/TeX", "input/MathML", "input/AsciiMath", "output/SVG"],
extensions: ["tex2jax.js","mml2jax.js","asciimath2jax.js","toMathML.js"],
TeX: {extensions: window.Array("AMSmath.js","AMSsymbols.js","autoload-all.js")},
tex2jax: {inlineMath: [['$','$'],['\\(','\\)']], preview:"none"},
mml2jax: {preview:"none"},
asciimath2jax: {preview:"none"},
SVG: {useFontCache: true, useGlobalCache: false, EqnChunk: 1000000, EqnDelay: 0},
//
// This gets run before MathJax queues any actions
//
AuthorInit: function () {
MathJax = window.MathJax;
delete MathJax.Hub.config.styles; // don't need any styles
MathJax.Hub.Startup.MenuZoom = function () {}; // don't load menu or zoom code
MathJax.Extension.MathEvents = {
Event:{}, Touch:{}, Hover:{} // fake structure to avid errors
};
MathJax.Ajax.loaded[MathJax.Ajax.fileURL("[MathJax]/extensions/MathEvents.js")] = true;
//
// When creating stylesheets, no need to wait for them
// to become active, so just do the callback
//
MathJax.Ajax.timer.create = function (callback,node) {
callback = MathJax.Callback(callback);
callback(this.STATUS.OK);
return callback;
};
//
// Use the console for messages, if we are requesting them
//
MathJax.Message.Set = function (text,n,delay) {
if (displayMessages && n !== 0) {
if (text instanceof window.Array)
{text = MathJax.Localization._.apply(MathJax.Localization,text)}
console.error(text);
}
};
MathJax.Message.Clear = function () {};
MathJax.Message.Remove = function () {};
MathJax.Message.Init = function () {};
//
// Trap Math Processing Errors
//
MathJax.Hub.Register.MessageHook("Math Processing Error",function (message) {
AddError("Math Processing Error: "+message[2].message);
});
MathJax.Hub.Register.MessageHook("SVG Jax - unknown char",function (message) {
AddError("SVG - Unknown character: U+"+message[1].toString(16).toUpperCase()+
" in "+(message[2].fonts||["unknown"]).join(","),!undefinedChar);
});
MathJax.Hub.Register.MessageHook("MathML Jax - unknown node type",function (message) {
AddError("MathML - Unknown node type: "+message[1]);
});
MathJax.Hub.Register.MessageHook("MathML Jax - parse error",function (message) {
AddError("MathML - "+message[1]);
});
MathJax.Hub.Register.MessageHook("AsciiMath Jax - parse error",function (message) {
AddError("AsciiMath parse error: "+message[1]);
});
MathJax.Hub.Register.MessageHook("TeX Jax - parse error",function (message) {
AddError("TeX parse error: "+message[1]);
});
//
// Set the delays to 0 (we don't need to update the screen)
//
MathJax.Hub.processSectionDelay = 0;
MathJax.Hub.processUpdateTime = 10000000; // don't interrupt processing of output
MathJax.Hub.processUpdateDelay = 0;
//
// Adjust the SVG output jax
//
MathJax.Hub.Register.StartupHook("SVG Jax Config",function () {
var SVG = MathJax.OutputJax.SVG, HTML = MathJax.HTML;
//
// Don't need the styles
//
delete SVG.config.styles
SVG.Augment({
//
// Set up the default ex-size and width
//
InitializeSVG: function () {
this.defaultEx = 6;
this.defaultWidth = 100;
},
//
// Adjust preTranslate() to not try to find the ex-size or
// the container widths.
//
preTranslate: function (state) {
var scripts = state.jax[this.id], i, m = scripts.length,
script, prev, span, div, jax, ex, em,
maxwidth = 100000, relwidth = false, cwidth,
linebreak = this.config.linebreaks.automatic,
width = this.config.linebreaks.width;
//
// Loop through the scripts
//
for (i = 0; i < m; i++) {
script = scripts[i]; if (!script.parentNode) continue;
//
// Remove any existing output
//
prev = script.previousSibling;
if (prev && String(prev.className).match(/^MathJax(_SVG)?(_Display)?( MathJax(_SVG)?_Processing)?$/))
{prev.parentNode.removeChild(prev)}
//
// Add the span, and a div if in display mode,
// then set the role and mark it as being processed
//
jax = script.MathJax.elementJax; if (!jax) continue;
jax.SVG = {display: (jax.root.Get("display") === "block")}
span = div = HTML.Element("span",{
style: {"font-size": this.config.scale+"%", display:"inline-block"},
className:"MathJax_SVG", id:jax.inputID+"-Frame", isMathJax:true, jaxID:this.id
});
if (jax.SVG.display) {
div = HTML.Element("div",{className:"MathJax_SVG_Display"});
div.appendChild(span);
}
//
// Mark math for screen readers
// (screen readers don't know about role="math" yet, so use "textbox" instead)
//
div.setAttribute("role","textbox"); div.setAttribute("aria-readonly","true");
div.className += " MathJax_SVG_Processing";
script.parentNode.insertBefore(div,script);
//
// Set SVG data for jax
//
jax.SVG.ex = ex = (data||defaults).ex;
jax.SVG.em = em = ex / SVG.TeX.x_height * 1000; // scale ex to x_height
jax.SVG.cwidth = width / em * 1000;
jax.SVG.lineWidth = (linebreak ? width / em * 1000 : SVG.BIGDIMEN);
}
//
// Set state variables used for displaying equations in chunks
//
state.SVGeqn = state.SVGlast = 0; state.SVGi = -1;
state.SVGchunk = this.config.EqnChunk;
state.SVGdelay = false;
}
});
//
// TEXT boxes use getBBox, which isn't implemented, so
// use a monspace font and fake the size. Since these
// are used only for error messages and undefined characters,
// this should be good enough for now.
//
SVG.BBOX.TEXT.Augment({
Init: function (scale,text,def) {
if (!def) {def = {}}; def.stroke = "none";
this.SUPER(arguments).Init.call(this,def);
SVG.addText(this.element,text);
var bbox = {width: text.length * 8.5, height: 18, y: -12};
scale *= 1000/SVG.em;
this.element.setAttribute("style","font-family: monospace");
this.element.setAttribute("transform","scale("+scale+") matrix(1 0 0 -1 0 0)");
this.w = this.r = bbox.width*scale; this.l = 0;
this.h = this.H = -bbox.y*scale;
this.d = this.D = (bbox.height + bbox.y)*scale;
}
});
});
//
// Start the typesetting queue when MathJax is ready
// (reseting the counters so that the initial math doesn't affect them)
//
MathJax.Hub.Register.StartupHook("End",function () {
MathJax.OutputJax.SVG.resetGlyphs(true);
MathJax.ElementJax.mml.ID = 0;
serverState = STATE.READY;
MathJax.Hub.Queue(StartQueue);
});
}
};
if (extensions) {
//
// Parse added extensions list and add to standard ones
//
var extensionList = extensions.split(/s*,\s*/);
for (var i = 0; i < extensionList.length; i++) {
var matches = extensionList[i].match(/^(.*?)(\.js)?$/);
window.MathJax.extensions.push(matches[1] + '.js');
}
}
//
// Turn arrays into jsdom window arrays
// (so "instanceof Array" will identify them properly)
//
var adjustArrays = function (obj) {
for (var id in obj) {if (obj.hasOwnProperty(id)) {
if (obj[id] instanceof Array) {
var A = window.Array();
obj[id] = A.concat.apply(A,obj[id]);
} else if (typeof obj[id] === "object") {
adjustArrays(obj[id]);
}
}}
}
if (MathJaxConfig) {
adjustArrays(MathJaxConfig);
Insert(window.MathJax,MathJaxConfig);
}
}
//
// Insert one objects into another
//
function Insert(dst,src) {
for (var id in src) {if (src.hasOwnProperty(id)) {
// allow for concatenation of arrays?
if (typeof src[id] === 'object' && !(src[id] instanceof Array) &&
(typeof dst[id] === 'object' || typeof dst[id] === 'function'))
{Insert(dst[id],src[id])} else {dst[id] = src[id]}
}}
return dst;
}
//
// Load MathJax into the DOM
//
function StartMathJax() {
serverState = STATE.STARTED;
var script = document.createElement("script");
script.src = MathJaxPath;
script.onerror = function () {AddError("Can't load MathJax.js from "+MathJaxPath)}
document.head.appendChild(script);
}
/********************************************************************/
//
// Return an error value (and report it to console)
//
function ReportError(message,currentCallback) {
AddError(message);
(currentCallback||callback)({errors: errors});
}
//
// Add an error to the error list and display it on the console
//
function AddError(message,nopush) {
if (displayErrors) console.error(message);
if (!nopush) errors.push(message);
}
/********************************************************************/
//
// Creates the MathML output (taking MathJax resets
// into account)
//
function GetMML(result) {
if (!data.mml && !data.speakText) return;
var jax = MathJax.Hub.getAllJax()[0];
try {result.mml = jax.root.toMathML('',jax)} catch(err) {
if (!err.restart) {throw err;} // an actual error
return MathJax.Callback.After(window.Array(GetMML,result),err.restart);
}
}
//
// Creates the speech string and updates the MathML to include it, if needed
//
function GetSpeech(result) {
if (!data.speakText) return;
speech.setupEngine({semantics: true, domain: data.speakRuleset, style: data.speakStyle});
result.speakText = speech.processExpression(result.mml);
if (data.mml) {
var jax = MathJax.Hub.getAllJax()[0];
jax.root.alttext = result.speakText;
if (jax.root.attrNames) {jax.root.attrNames.push("alttext")}
result.mml = jax.root.toMathML('',jax);
}
}
//
// Create SVG output and IMG output, if requested
//
function GetSVG(result) {
if (!data.svg && !data.png && !data.img) return;
var jax = MathJax.Hub.getAllJax()[0]; if (!jax) return;
var script = jax.SourceElement(),
svg = script.previousSibling.getElementsByTagName("svg")[0];
svg.setAttribute("xmlns","http://www.w3.org/2000/svg");
//
// Add the speech text and mark the SVG appropriately
//
if (data.speakText) {
ID++; var id = "MathJax-SVG-"+ID;
svg.setAttribute("role","math");
svg.setAttribute("aria-labelledby",id+"-Title "+id+"-Desc");
for (var i=0, m=svg.childNodes.length; i < m; i++)
svg.childNodes[i].setAttribute("aria-hidden",true);
var node = MathJax.HTML.Element("desc",{id:id+"-Desc"},[result.speakText]);
svg.insertBefore(node,svg.firstChild);
node = MathJax.HTML.Element("title",{id:id+"-Title"},["Equation"]);
svg.insertBefore(node,svg.firstChild);
}
//
// SVG data is modified to add linebreaks for readability,
// and to put back the xlink namespace that is removed in HTML5
//
var svgdata = svg.outerHTML.replace(/><([^/])/g,">\n<$1")
.replace(/(<\/[a-z]*>)(?=<\/)/g,"$1\n")
.replace(/(<use [^>]*)(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("");
}
}
//
// 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
}
}
/********************************************************************/
//
// Start typesetting the queued expressions
//
function StartQueue() {
data = callback = null; // clear existing equation, if any
errors = []; // clear any errors
if (!queue.length) return; // return if nothing to do
serverState = STATE.BUSY;
var result = {}, $$ = window.Array;
//
// Get the math data and callback
// and set the content with the proper delimiters
//
var item = queue.shift();
data = item[0]; callback = item[1];
var delim = delimiters[data.format];
var math = data.math;
if (data.format !== "MathML")
math = math.replace(/&/g,"&amp;").replace(/</g,"&lt;").replace(/>/g,"&gt;");
content.innerHTML = delim[0]+math+delim[1];
html.setAttribute("xmlns:"+data.xmlns,"http://www.w3.org/1998/Math/MathML");
//
// Set the SVG and TeX parameters
// according to the requested data
//
var SVG = MathJax.OutputJax.SVG,
TEX = MathJax.InputJax.TeX,
HUB = MathJax.Hub;
SVG.defaultEx = data.ex;
SVG.defaultWidth = data.width * data.ex;
SVG.config.linebreaks.automatic = data.linebreaks;
SVG.config.linebreaks.width = data.width * data.ex;
SVG.config.useFontCache = data.useFontCache;
SVG.config.useGlobalCache = data.useGlobalCache;
TEX.config.equationNumbers.autoNumber = data.equationNumbers;
//
// Set the state from data.state or clear it
//
GetState(data.state);
//
// Set up a timeout timer to restart MathJax if it runs too long,
// Then push the Typeset call, the MathML, speech, SVG, and PNG calls,
// and our TypesetDone routine
//
timer = setTimeout(RestartMathJax,data.timeout);
HUB.Queue(
$$("Typeset",HUB),
$$(TypesetDone,result),
$$(GetMML,result),
$$(GetSpeech,result),
$$(GetSVG,result),
$$(GetPNG,result),
$$(ReturnResult,result)
);
}
//
// Update the MathJax values from the state,
// or clear them if there is no state.
//
function GetState(state) {
var SVG = MathJax.OutputJax.SVG,
TEX = MathJax.InputJax.TeX,
MML = MathJax.ElementJax.mml,
AMS = MathJax.Extension["TeX/AMSmath"],
HUB = MathJax.Hub, HTML = MathJax.HTML,
GLYPH = SVG.BBOX.GLYPH;
if (state && state.AMS) {
AMS.startNumber = state.AMS.startNumber;
AMS.labels = state.AMS.labels;
AMS.IDs = state.AMS.IDs;
MML.SUPER.ID = state.mmlID;
GLYPH.glyphs = state.glyphs;
GLYPH.defs = state.defs;
GLYPH.n = state.n;
ID = state.ID;
} else {
if (state) {state.AMS = {}}
SVG.resetGlyphs(true);
if (data.useGlobalCache) {
state.glyphs = {};
state.defs = HTML.Element("defs");
state.n = 0;
}
TEX.resetEquationNumbers();
MML.SUPER.ID = ID = 0;
}
}
//
// When the expression is typeset,
// clear the timeout timer, if any,
// and update the MathJax state,
//
function TypesetDone(result) {
if (timer) {clearTimeout(timer); timer = null}
html.removeAttribute("xmlns:"+data.xmlns);
var state = data.state;
if (state) {
var AMS = MathJax.Extension["TeX/AMSmath"];
var GLYPH = MathJax.OutputJax.SVG.BBOX.GLYPH;
state.AMS.startNumber = AMS.startNumber;
state.AMS.labels = AMS.labels;
state.AMS.IDs = AMS.IDs;
state.mmlID = MathJax.ElementJax.mml.SUPER.ID;
state.glyphs = GLYPH.glyphs;
state.defs = GLYPH.defs;
state.n = GLYPH.n;
state.ID = ID;
}
}
//
// Return the result object, and
// do the next queued expression
//
function ReturnResult(result) {
if (errors.length) {result.errors = errors}
callback(result);
serverState = STATE.READY;
StartQueue();
}
/********************************************************************/
//
// If MathJax times out, discard the DOM
// and load a new one (get a fresh MathJax)
//
function RestartMathJax() {
if (timer) {
MathJax.Hub.queue.queue = []; // clear MathJax queue, so pending operations won't fire
MathJax = timer = window = document = html = content = null;
ReportError("Timeout waiting for MathJax: restarting");
serverState = STATE.STOPPED;
}
GetWindow();
ConfigureMathJax();
StartMathJax();
}
/********************************************************************/
//
// The API call to typeset an equation
//
// %%% cache results?
// %%% check types and values of parameters
//
exports.typeset = function (data,callback) {
if (!callback || typeof(callback) !== "function") {
if (displayErrors) console.error("Missing callback");
return;
}
var options = {};
for (var id in defaults) {if (defaults.hasOwnProperty(id)) {
options[id] = (data.hasOwnProperty(id) ? data[id]: defaults[id]);
}}
if (data.state) {options.state = data.state}
if (!delimiters[options.format]) {ReportError("Unknown format: "+options.format,callback); return}
queue.push([options,callback]);
if (serverState == STATE.STOPPED) {RestartMathJax()}
if (serverState == STATE.READY) StartQueue();
}
//
// Manually start MathJax (this is done automatically
// when the first typeset() call is made)
//
exports.start = function () {RestartMathJax()}
//
// Configure MathJax and the API
// You can pass additional configuration options to MathJax using the
// MathJax property, and can set displayErrors and displayMessages
// that control the display of error messages, and extensions to add
// additional MathJax extensions to the base or to sub-categories.
//
// E.g.
// mjAPI.config({
// MathJax: {SVG: {font: "STIX-Web"}},
// displayErrors: false,
// extensions: 'Safe,TeX/noUndefined'
// });
//
exports.config = function (config) {
if (config.displayMessages != null) {displayMessages = config.displayMessages}
if (config.displayErrors != null) {displayErrors = config.displayErrors}
if (config.undefinedCharError != null) {undefinedChar = config.undefinedCharError}
if (config.extensions != null) {extensions = config.extensions}
if (config.MathJax) {MathJaxConfig = config.MathJax}
}