How can I read the mp3 files from the mongodb that I have stored using gridFS? - node.js

Question

My code:
storeAudio.js
var mongoose = require('mongoose');
var fs = require('fs');
var Grid = require('gridfs-stream');
Grid.mongo=mongoose.mongo;
//establish mongoDB connection
mongoose.Promise = global.Promise;
var conn = mongoose.createConnection('mongodb://localhost:27017/aHolyBoly');
conn.once('open',function(){
var gfs = Grid(conn.db);
// var db = new mongo.Db('aHolyBoly', new mongo.Server("127.0.0.1", 27017));
//var gfs = Grid(db, mongo);
var writeStream = gfs.createWriteStream({
filename:'song1.mp3'
});
fs.createReadStream('../list/hero.mp3').pipe(writeStream);
writeStream.on('close',function(file){
console.log(file.filename +'Written to db');
});
});
my mp3 file is written successfully in the DB.
Now my aim is to create the routes using express so that I can use it as an API using as providers in my angular2 app.
server.js
var mongoose = require('mongoose');
var fs = require('fs');
var Grid = require('gridfs-stream');
Grid.mongo=mongoose.mongo;
//establish mongoDB connection
mongoose.Promise = global.Promise;
var conn = mongoose.createConnection('mongodb://localhost:27017/aHolyBoly');
conn.once('open',function(){
var gfs = Grid(conn.db);
// var db = new mongo.Db('aHolyBoly', new mongo.Server("127.0.0.1", 27017));
//var gfs = Grid(db, mongo);
var writeStream = gfs.createWriteStream({
filename:'song1.mp3'
});
fs.createReadStream('../list/hero.mp3').pipe(writeStream);
writeStream.on('close',function(file){
console.log(file.filename +'Written to db');
});
});
Here somewhere in my code, I am unable to find the song written in the Db using gridFS.
link for gridFS API gridFS API Link
I want to create an application using ionic2 which contains a search bar and when I enter song name it will display the songs and I can play it.
I am struggling from 1 week written this 3 times on stack but unable to get the answer.

Answer 1

I bet you are a newbie in server-side web development, because your question kinda misses the whole point of creating a node.js application.
When writing a server the goal is that the server cannot access the files on the client's computer. This means your app acts as a thin client. Don't confuse that node.js runs on your computer as well: it creates his own mock server which acts as a real faraway computer even though it is on your very same computer that you use. For this reason you cannot modify files outside of your project library, or even if you can it will be a hack and it is not what node.js is made for.
If you want a program specifically to modify files on your computer you should learn a thick client programming language, like C, C++ or Java. They only run on your computer ad have full access to any of your files.
If you are sticking to JavaScript for whatever reason, it as well has the power to modify your files, however it is still not what it is intended for. You have to give it special permissions and it still is weird that you give access to all your personal files to your browser. However this Javascript code id on the client side i.e. you don't need node.js, neither express. The client code can be written and run with a single browser. Check out this article for more information about it.
But if you are still convinced that node is your way, then you have some options still. First, but I don't think it is your answer: write an upload website which uploads the mp3 files to your server (still on the same computer but places it in the project location). It should work and look like an actual website (like what node.js was made for). And finally what you're asking for can be kinda achieved, but it's reaaaaally hacky, you can try and just reference it from the application path like
var fs = require('fs'),
path = require('path'),
filePath = path.join(__dirname, '../outerfile.mp3')
filePath2 = path.join('/var/outerfile.mp3');
However it is probably platform dependent how it will run and not likely to be working at all.
My final advice: you should consider using another language for your project.