Variable declarations
This commit is contained in:
Joseph Rautenbach
parent
73942d746b
commit
49784697ab
85
app.js
85
app.js
@ -1,47 +1,46 @@
|
||||
var fs = require('fs');
|
||||
var shell = require('shelljs');
|
||||
const fs = require('fs');
|
||||
const shell = require('shelljs');
|
||||
const express = require('express');
|
||||
|
||||
var express = require('express');
|
||||
const port = 3001;
|
||||
|
||||
var port = 3001;
|
||||
|
||||
var staticDir = 'static/';
|
||||
var tempDirRoot = 'temp/';
|
||||
var outputDir = 'output/';
|
||||
var httpOutputURL = 'output/';
|
||||
|
||||
// Command to compile .tex file to .dvi file. Timeout kills LaTeX after 5 seconds if held up
|
||||
var latexCMD = 'timeout 5 latex -interaction nonstopmode -halt-on-error --no-shell-escape equation.tex';
|
||||
|
||||
// Command to convert .dvi to .svg file
|
||||
var dvisvgmCMD = 'dvisvgm --no-fonts --scale=OUTPUT_SCALE --exact equation.dvi';
|
||||
|
||||
var dockerImageName = 'blang/latex:ubuntu'; // https://github.com/blang/latex-docker
|
||||
|
||||
// Command to run the above commands in a new Docker container (with LaTeX preinstalled)
|
||||
var dockerCMD = `cd TEMP_DIR_NAME && exec docker run --rm -i --user="$(id -u):$(id -g)" --net=none -v "$PWD":/data "${dockerImageName}" /bin/sh -c "${latexCMD} && ${dvisvgmCMD}"`;
|
||||
|
||||
// Commands to convert .svg to .png/.jpg and compress
|
||||
var svgToImageCMD = 'svgexport SVG_FILE_NAME OUT_FILE_NAME';
|
||||
var imageMinCMD = 'imagemin IN_FILE_NAME > OUT_FILE_NAME';
|
||||
const staticDir = 'static/';
|
||||
const tempDirRoot = 'temp/';
|
||||
const outputDir = 'output/';
|
||||
const httpOutputURL = 'output/';
|
||||
|
||||
// Checklist of valid formats and scales, to verify form values are correct
|
||||
var validFormats = ['SVG', 'PNG', 'JPG'];
|
||||
var validScales = ['10%', '25%', '50%', '75%', '100%', '125%', '150%', '200%', '500%', '1000%'];
|
||||
const validFormats = ['SVG', 'PNG', 'JPG'];
|
||||
const validScales = ['10%', '25%', '50%', '75%', '100%', '125%', '150%', '200%', '500%', '1000%'];
|
||||
// Percentage scales mapped to floating point values used in arguments
|
||||
var validScalesInternal = ['0.1', '0.25', '0.5', '0.75', '1.0', '1.25', '1.5', '2.0', '5.0', '10.0'];
|
||||
const validScalesInternal = ['0.1', '0.25', '0.5', '0.75', '1.0', '1.25', '1.5', '2.0', '5.0', '10.0'];
|
||||
|
||||
var fontSize = 12;
|
||||
// Command to compile .tex file to .dvi file. Timeout kills LaTeX after 5 seconds if held up
|
||||
const latexCMD = 'timeout 5 latex -interaction nonstopmode -halt-on-error --no-shell-escape equation.tex';
|
||||
|
||||
// Command to convert .dvi to .svg file
|
||||
const dvisvgmCMD = 'dvisvgm --no-fonts --scale=OUTPUT_SCALE --exact equation.dvi';
|
||||
|
||||
const dockerImageName = 'blang/latex:ubuntu'; // https://github.com/blang/latex-docker
|
||||
|
||||
// Command to run the above commands in a new Docker container (with LaTeX preinstalled)
|
||||
const dockerCMD = `cd TEMP_DIR_NAME && exec docker run --rm -i --user="$(id -u):$(id -g)" --net=none -v "$PWD":/data "${dockerImageName}" /bin/sh -c "${latexCMD} && ${dvisvgmCMD}"`;
|
||||
|
||||
// Commands to convert .svg to .png/.jpg and compress
|
||||
const svgToImageCMD = 'svgexport SVG_FILE_NAME OUT_FILE_NAME';
|
||||
const imageMinCMD = 'imagemin IN_FILE_NAME > OUT_FILE_NAME';
|
||||
|
||||
const fontSize = 12;
|
||||
|
||||
// LaTeX document template
|
||||
var preamble = `
|
||||
const preamble = `
|
||||
\\usepackage{amsmath}
|
||||
\\usepackage{amssymb}
|
||||
\\usepackage{amsfonts}
|
||||
\\usepackage[utf8]{inputenc}
|
||||
`;
|
||||
|
||||
var documentTemplate = `
|
||||
const documentTemplate = `
|
||||
\\documentclass[${fontSize}pt]{article}
|
||||
${preamble}
|
||||
\\thispagestyle{empty}
|
||||
@ -59,9 +58,9 @@ if (!fs.existsSync(outputDir)) {
|
||||
fs.mkdirSync(outputDir);
|
||||
}
|
||||
|
||||
var app = express();
|
||||
const app = express();
|
||||
|
||||
var bodyParser = require('body-parser');
|
||||
const bodyParser = require('body-parser');
|
||||
app.use(bodyParser.json());
|
||||
app.use(bodyParser.urlencoded({extended: true}));
|
||||
|
||||
@ -75,26 +74,26 @@ app.post('/convert', function (req, res) {
|
||||
if (req.body.latexInput) {
|
||||
if (validScales.includes(req.body.outputScale)) {
|
||||
if (validFormats.includes(req.body.outputFormat)) {
|
||||
var id = generateID(); // Generate unique ID for filename
|
||||
const id = generateID(); // Generate unique ID for filename
|
||||
|
||||
var eqnInput = req.body.latexInput.trim();
|
||||
let eqnInput = req.body.latexInput.trim();
|
||||
if (/\\\\(?!$)/.test(eqnInput) && !eqnInput.includes("&")) { // if any "\\" not at EOF, unless intentionally aligned with &
|
||||
eqnInput = '&' + eqnInput.replace(/\\\\(?!$)/g, "\\\\&"); // replace any "\\" not at EOF with "\\&", to enforce left alignment
|
||||
}
|
||||
|
||||
shell.mkdir(`${tempDirRoot}${id}`);
|
||||
|
||||
var document = documentTemplate.replace('EQUATION', eqnInput);
|
||||
const document = documentTemplate.replace('EQUATION', eqnInput);
|
||||
fs.writeFileSync(`${tempDirRoot}${id}/equation.tex`, document); // Write generated .tex file
|
||||
|
||||
var result = {};
|
||||
let result = {};
|
||||
|
||||
var finalDockerCMD = dockerCMD.replace('TEMP_DIR_NAME', `${tempDirRoot}${id}`);
|
||||
let finalDockerCMD = dockerCMD.replace('TEMP_DIR_NAME', `${tempDirRoot}${id}`);
|
||||
finalDockerCMD = finalDockerCMD.replace('OUTPUT_SCALE', validScalesInternal[validScales.indexOf(req.body.outputScale)]);
|
||||
|
||||
var fileFormat = req.body.outputFormat.toLowerCase();
|
||||
const fileFormat = req.body.outputFormat.toLowerCase();
|
||||
|
||||
// Asynchronously compile and render the LaTeX to svg
|
||||
// Asynchronously compile and render the LaTeX to an image
|
||||
shell.exec(finalDockerCMD, {async: true}, function() {
|
||||
if (fs.existsSync(`${tempDirRoot}${id}/equation.svg`)) {
|
||||
if (fileFormat === 'svg') { // Converting to SVG, no further processing required
|
||||
@ -103,7 +102,7 @@ app.post('/convert', function (req, res) {
|
||||
} else {
|
||||
|
||||
// Convert svg to png/jpg
|
||||
var finalSvgToImageCMD = svgToImageCMD.replace('SVG_FILE_NAME', `${tempDirRoot}${id}/equation.svg`);
|
||||
let finalSvgToImageCMD = svgToImageCMD.replace('SVG_FILE_NAME', `${tempDirRoot}${id}/equation.svg`);
|
||||
finalSvgToImageCMD = finalSvgToImageCMD.replace('OUT_FILE_NAME', `${tempDirRoot}${id}/equation.${fileFormat}`);
|
||||
if (fileFormat === 'jpg') { // Add a white background for jpg images
|
||||
finalSvgToImageCMD += ' "svg {background: white}"';
|
||||
@ -113,7 +112,7 @@ app.post('/convert', function (req, res) {
|
||||
// Ensure conversion was successful; eg. fails if `svgexport` or `imagemin` is not installed
|
||||
if (fs.existsSync(`${tempDirRoot}${id}/equation.${fileFormat}`)) {
|
||||
// Compress the resultant image
|
||||
var finalImageMinCMD = imageMinCMD.replace('IN_FILE_NAME', `${tempDirRoot}${id}/equation.${fileFormat}`);
|
||||
let finalImageMinCMD = imageMinCMD.replace('IN_FILE_NAME', `${tempDirRoot}${id}/equation.${fileFormat}`);
|
||||
finalImageMinCMD = finalImageMinCMD.replace('OUT_FILE_NAME', `${tempDirRoot}${id}/equation_compressed.${fileFormat}`);
|
||||
shell.exec(finalImageMinCMD);
|
||||
|
||||
@ -152,8 +151,8 @@ app.listen(port, function() {
|
||||
|
||||
|
||||
function generateID() { // Generate a random 16-char hexadecimal ID
|
||||
var output = '';
|
||||
for (var i = 0; i < 16; i++) {
|
||||
let output = '';
|
||||
for (let i = 0; i < 16; i++) {
|
||||
output += '0123456789abcdef'.charAt(Math.floor(Math.random() * 16));
|
||||
}
|
||||
return output;
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user