gulpfile.js

var gulp = require('gulp'),
    jshint = require('gulp-jshint'),
    gulpif = require('gulp-if'),
    concat = require('gulp-concat'),
    uglify = require('gulp-uglify'),
    cleanCSS = require('gulp-clean-css'),
    removeCode = require('gulp-remove-code'),
    merge = require('merge-stream'),
    del = require('del'),
    zip = require('gulp-zip'),
    gzip = require('gulp-gzip'),
    htmlmin = require('gulp-htmlmin'),
    replace = require('gulp-replace'),
    fs = require('fs'),
    smoosher = require('gulp-smoosher');
    size = require('gulp-filesize');

var en_lang = true;
var fr_lang = false;
var es_lang = false;
var de_lang = false;
var it_lang = false;
var ja_lang = false;
var pl_lang = false;
var ptbr_lang = false;
var ru_lang = false;
var uk_lang = false;
var zh_cn_lang = false;
var hu_lang = false;
var tr_lang = false;

function clean() {
    return del(['dist']);
    
}

function clean2() {
    return del(['dist/js', 'dist/css']);
}
function lint() {
    return gulp.src('www/js/**/app.js')
        .pipe(jshint())
        .pipe(jshint.reporter('default'));
}

function Copytest() {
    return merge(
        gulp.src(['www/index.html'])
        .pipe(removeCode({production: false}))
        .pipe(removeCode({cleanheader: true}))
        .pipe(gulp.dest('dist')),
        gulp.src(['www/images/**/*.*'])
            .pipe(gulp.dest('dist/images'))
    )
}

function Copy() {
    return merge(
        gulp.src(['www/index.html'])
        .pipe(removeCode({production: true}))
        .pipe(removeCode({cleanheader: true}))
        .pipe(gulp.dest('dist')),
        gulp.src(['www/images/**/*.*'])
            .pipe(gulp.dest('dist/images'))
    )
}

function concatApptest() {
    return merge(
        gulp.src([ 'www/js/**/*.js'])
            .pipe(concat('app.js'))
            .pipe(removeCode({production: false}))
            .pipe(removeCode({cleanheader: true}))
            .pipe(gulp.dest('./dist/js')),

        gulp.src([ 'www/css/**/*.css'])
            .pipe(concat('style.css'))
            .pipe(gulp.dest('./dist/css/'))
    )
}

function concatApp() {
    return merge(
        gulp.src([ 'www/js/**/*.js'])
            .pipe(concat('app.js'))
            .pipe(removeCode({production: true}))
            .pipe(removeCode({cleanheader: true}))
            .pipe(gulp.dest('./dist/js')),

        gulp.src([ 'www/css/**/*.css'])
            .pipe(concat('style.css'))
            .pipe(gulp.dest('./dist/css/'))
    )
}

function replaceSVG() {
    return gulp.src('dist/index.html')
        .pipe(replace(/<!-- replaceSVG -->(.*?)<!-- \/replaceSVG -->/g, function (match, p1) {
            return fs.readFileSync('dist/images/jogdial.svg', 'utf8');
        }))
        .pipe(gulp.dest('dist'))
}

function clearlang() {
   // fetch command line arguments
    console.log("Enable Language:");
    const arg = (argList => {

      let arg = {}, a, opt, thisOpt, curOpt;
      for (a = 0; a < argList.length; a++) {

        thisOpt = argList[a].trim();
        opt = thisOpt.replace(/^\-+/, '');

        if (opt === thisOpt) {

          // argument value
          if (curOpt) arg[curOpt] = opt;
          curOpt = null;

        }
        else {

          // argument name
          curOpt = opt;
          arg[curOpt] = true;

        }

      }

      return arg;

    })(process.argv);
    if ((arg.lang == 'grbl') ) {
        en_lang = true;
        fr_lang = true;
        es_lang = true;
        de_lang = true;
        it_lang = true;
        ja_lang = false;
        hu_lang = false;
        pl_lang = true;
        ptbr_lang = true;
        ru_lang = true;
        tr_lang = false;
        uk_lang = true;
        zh_cn_lang = false;
    }
    if ((typeof arg.lang == 'undefined') || (arg.lang == 'all')) {
        en_lang = true;
        fr_lang = true;
        es_lang = true;
        de_lang = true;
        it_lang = true;
        ja_lang = true;
        hu_lang = true;
        pl_lang = true;
        ptbr_lang = true;
        ru_lang = true;
        tr_lang = true;
        uk_lang = true;
        zh_cn_lang = true;
    }
    if (arg.lang == 'en'){
        en_lang = true;
    }
    if(en_lang){
        console.log("en");
    }
    if (arg.lang == 'fr'){
        fr_lang = true;
    }
    if(fr_lang){
        console.log("fr");
    }
    if (arg.lang == 'es'){
        es_lang = true;
    }
    if(es_lang){
        console.log("es");
    }
    if (arg.lang == 'de'){
        de_lang = true;
    }
    if(de_lang){
        console.log("de");
    }
    if (arg.lang == 'it'){
        it_lang = true;
    }
    if (arg.lang == 'ja'){
        ja_lang = true;
    }
    if(hu_lang){
        console.log("hu");
    }
    if (arg.lang == 'hu'){
        hu_lang = true;
    }
    if(it_lang){
        console.log("it");
    }
    if(ja_lang){
        console.log("ja");
    }
    if (arg.lang == 'pl'){
        pl_lang = true;
    }
    if(pl_lang){
        console.log("pl");
    }
    if (arg.lang == 'ptbr'){
        ptbr_lang = true;
    }
    if(ptbr_lang){
        console.log("ptbr");
    }
    if (arg.lang == 'ru'){
        ru_lang = true;
    }
    if(ru_lang){
        console.log("ru");
    }
    if (arg.lang == 'tr'){
        tr_lang = true;
    }
    if(tr_lang){
        console.log("tr");
    }
    if (arg.lang == 'uk'){
        uk_lang = true;
    }
    if(uk_lang){
        console.log("uk");
    }
    if (arg.lang == 'zh_CN'){
        zh_cn_lang = true;
    }
    if(zh_cn_lang){
        console.log("zh_CN");
    }
    return gulp.src('dist/js/app.js')
        .pipe(removeCode({de_lang_disabled: !de_lang}))
        .pipe(removeCode({en_lang_disabled: !en_lang}))
        .pipe(removeCode({es_lang_disabled: !es_lang}))
        .pipe(removeCode({fr_lang_disabled: !fr_lang}))
        .pipe(removeCode({it_lang_disabled: !it_lang}))
        .pipe(removeCode({ja_lang_disabled: !ja_lang}))
        .pipe(removeCode({hu_lang_disabled: !hu_lang}))
        .pipe(removeCode({pl_lang_disabled: !pl_lang}))
        .pipe(removeCode({ptbr_lang_disabled: !ptbr_lang}))
        .pipe(removeCode({ru_lang_disabled: !ru_lang}))
        .pipe(removeCode({tr_lang_disabled: !tr_lang}))
        .pipe(removeCode({uk_lang_disabled: !uk_lang}))
        .pipe(removeCode({zh_cn_lang_disabled: !zh_cn_lang}))
        .pipe(gulp.dest('./dist/js/'))
}

function minifyApp() {
    return merge(
        gulp.src(['dist/js/app.js'])
            .pipe(uglify({mangle: true}))
            .pipe(gulp.dest('./dist/js/')),

        gulp.src('dist/css/style.css')
            .pipe(cleanCSS({debug: true}, function(details) {
                console.log(details.name + ': ' + details.stats.originalSize);
                console.log(details.name + ': ' + details.stats.minifiedSize);
            }))
            .pipe(gulp.dest('./dist/css/')),

        gulp.src('dist/index.html')
            .pipe(htmlmin({collapseWhitespace: true, minifyCSS: true}))
            .pipe(gulp.dest('dist'))
    )
}

function includehtml() {
    return merge(
        gulp.src('dist/index.html')
            .pipe(replace(/<file-include w3-include-html="'sub\/(.*?)'"><\/file-include>/g, function (match, p1) {
                return fs.readFileSync('www/sub/' + p1, 'utf8');
            }))
            .pipe(gulp.dest('dist/'))
    )
}

function smoosh() {
    return gulp.src('dist/index.html')
        .pipe(smoosher())
        .pipe(gulp.dest('dist'))
}

function compress() {
    return gulp.src('dist/index.html')
        .pipe(gzip({ gzipOptions: { level: 9} }))
        .pipe(gulp.dest('.'))
        .pipe(size());
}


gulp.task(clean);
gulp.task(lint);
gulp.task(Copy);
gulp.task(Copytest);
gulp.task(replaceSVG);
gulp.task(concatApp);
gulp.task(concatApptest);
gulp.task(minifyApp);
gulp.task(smoosh);
gulp.task(clean2);
gulp.task(clearlang)

var defaultSeries = gulp.series(clean,  lint, Copy, concatApp, minifyApp, includehtml, includehtml, smoosh);
//var packageSeries = gulp.series(clean,  lint, Copy, concatApp, minifyApp, smoosh, compress);
var packageSeries = gulp.series(clean,  lint, Copy, concatApp, includehtml, includehtml, replaceSVG, clearlang, minifyApp, smoosh, compress, clean2);
var package2Series = gulp.series(clean,  lint, Copy, concatApp, includehtml, includehtml, replaceSVG, smoosh);
var package2testSeries = gulp.series(clean,  lint, Copytest, concatApptest, includehtml, includehtml, replaceSVG, smoosh);

gulp.task('default', defaultSeries);
gulp.task('package', packageSeries);
gulp.task('package2', package2Series);
gulp.task('package2test', package2testSeries);