I am trying to make a download picker for my website, I searched on most websites for my solution!
And I am using npm modules (archiver, fs, express)
const express = require("express")
const nanoid = require("nanoid")
const fs = require("fs")
const archiver = require("archiver")
const formidable = require("formidable")
const os = require("os")
const streamZip = require("node-stream-zip")
const path = require("path")
const Dropbox = require("dropbox").Dropbox
require("isomorphic-fetch")
require("dotenv").config()
// setup Dropbox
const dbx = new Dropbox ({ fetch: fetch, accessToken: process.env.DBXACCESSTOKEN })
// get modules.json
const availableModules = JSON.parse(fs.readFileSync("../storage/data/modules.json"))
// setup express
const app = express()
app.use(express.json()) // to support JSON-encoded bodies
app.use(express.static("../public"))
app.use("/favicon.ico", express.static("../public/logo/favicon.ico"))
// disable caching
app.use((req, res, next) => {
res.set("Cache-Control", "max-age=1000")
next()
})
// dynamically serve get requests from requests.json
const getRequests = JSON.parse(fs.readFileSync("../storage/data/requests.json"))
const pathnames = getRequests.map(i=>i.url)
for (i of getRequests) app.get(i.url, (req, res) => {
const pathname = req._parsedOriginalUrl.pathname
const filePath = getRequests[pathnames.indexOf(pathname)].file
res.sendFile(filePath, { root: "../" })
})
app.get("/test", (req,res)=>res.send("hello world"))
// how to handle a post request, sent by the client-side js, to compile the pack
app.post("/download", function (req, res) {
// generate id and create pack paths
const packID = nanoid.customAlphabet("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", 5)()
console.log("packID = "+packID)
const localPackPath = path.join (os.tmpdir(), `${packID}.zip`)
const dropboxPackPath = `/packs/"LittleImprovementsCustom_${packID}".zip`
const output = fs.createWriteStream(localPackPath)
const archive = archiver("zip",{zlib:{level:9}})
// create variable with selected modules; gets updated later
let selectedModules = req.body.modules
console.log(selectedModules)
// system to deal with preferred packs
for (i of availableModules) {
if (
( i.prefers!=undefined && i.prefers.length!=0 ) // this module has prefers
&& ( selectedModules.includes(i.id) ) // this module has been selected
) {
console.log(i.id)
for (n of i.prefers) {
if (selectedModules.includes(n.id)) { // the module to prefer with has also been selected
selectedModules.splice(selectedModules.indexOf(n.delete),1) // remove the unpreferrred module
}
}
}
}
// system to deal with merged packs
for (i of availableModules) {
if (
( i.merges!=undefined && i.merges.length!=0 ) // this module has merges
&& ( selectedModules.includes(i.id) ) // this module has been selected
) {
for (n of i.merges) {
if (selectedModules.includes(n.id)) { // the mergeable module has been selected
// remove the two mergeable packs
selectedModules.splice(selectedModules.indexOf(i),1)
selectedModules.splice(selectedModules.indexOf(n.id),1)
// add the mergeWith pack
selectedModules.push(n.mergeWith)
}
}
}
}
output.on("close", ()=>{
console.log("pack generated at "+localPackPath)
dbx.filesUpload({path:dropboxPackPath,contents:fs.readFileSync(localPackPath)})
.then(()=>{
dbx.filesGetTemporaryLink({path:dropboxPackPath})
.then(shareLink=>{
if (shareLink.link!=undefined) resLink = shareLink.link
else resLink = shareLink.result.link
res.send(resLink) // send download link
fs.unlinkSync(localPackPath) // delete zip from local storage
})
.catch(error=>console.error(error))
})
.catch(error=>console.error(error))
})
output.on("end", ()=>console.log("data has been drained"))
archive.on("error", (error)=>{throw error})
archive.on("warning", (error)=> {
if (error.code=="ENOENT") console.warn(error)
else throw error
})
archive.pipe(output)
// add base files
for (i of ["credits.txt","pack.mcmeta","pack.png"]) {
archive.file("../storage/baseFiles/"+i, {name:i})
}
// add selectedModules.txt file
const infoText = `Little Improvements: Custom
Downloaded: ${new Date().toUTCString()}
ID: ${packID}
Platform: ${req.body.platform}
Selected modules:
${selectedModules.join("
")}`
archive.append(infoText,{name:"selectedModules.txt"})
// add rawSelectedModules.json file
archive.append(JSON.stringify(req.body.modules),{name:"assets/rawSelectedModules.json"})
let createdLangFiles = []
// add selected modules
for (i of availableModules) {
if (selectedModules.includes(i.id)) {
// add resource pack files
archive.directory("../storage/modules/"+i.id, "assets/minecraft")
// add lang files
if (i.lang) {
const moduleLangData = JSON.parse(fs.readFileSync(`../storage/lang/${i.id}.json`))
const createdLangNames = createdLangFiles.map(n=>n.name)
for (const [fileName, langData] of Object.entries(moduleLangData)) {
// check if the lang file has been added to createdLangFiles. if not, add it.
if (!createdLangNames.includes(fileName)) {
createdLangNames.push(fileName)
createdLangFiles.push ({
"name": fileName,
"source" : {},
"data" : { name : `assets/minecraft/lang/${fileName}` }
})
}
// add the lang data
for (const [langKey, langValue] of Object.entries(langData)) {
createdLangFiles[createdLangNames.indexOf(fileName)].source[langKey] = langValue
}
}
}
}
}
for (i of createdLangFiles) {
archive.append(JSON.stringify(i.source), i.data)
}
archive.finalize()
})
// system to deal with file uploads
app.post("/uploadpack", (req, res) => {
const form = new formidable.IncomingForm()
form.parse(req, (err, fields, files) =>{
if (err) {
next(err)
return
}
const zip = new streamZip ({
file: files.uploadedPack.path,
storeEntries: true
})
zip.on ("ready", () => {
// check if zip contains rawSelectedModules.json
if (!Object.values(zip.entries()).map(x=>x.name).includes("assets/rawSelectedModules.json")) {
// the file was not found, return an error
res.json({"found":false})
return
}
// Read rawSelectedModules.json from memory
const selectedModulesContents = JSON.parse(zip.entryDataSync("assets/rawSelectedModules.json").toString("utf8"))
console.log(selectedModulesContents)
// Do not forget to close the file once you're done
zip.close()
// send the selected modules in the response
res.json({"found":true,"modulesToSelect":selectedModulesContents})
})
// handle errors such as the file being upload not being a zip
zip.on("error", err => res.json({"found":false}))
})
})
// listen server with express
const server = app.listen(process.env.PORT || 3000, () => console.log("Server running"))
// export express stuff for testing
module.exports.app = app
module.exports.close = () => server.close
Ignore the dropbox part, and the other modules!
I need this to be done 4 times but the selected modules are conflicting The conflicting Error!
how do I achieve this?
Thank you!
question from:
https://stackoverflow.com/questions/65839663/how-do-i-create-a-download-picker-using-js-in-a-website 
