Tl GridFS

Convenience layer for Mongo's GridFS on Node.js applications

This module uses Aaron Heckmann's gridfs-stream module to stream data into GridFS.

Installing

npm install --save tl-gridfs

Usage

var gridfs = require('tl-gridfs');

Initialization

You must initialize it with your current Mongo instance and db connection before using it:

gridfs.init(db, mongo);

If you're using mongoose, just pass mongoose.connection.db and mongoose.mongo:

var mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/your-db-name', options);

mongoose.connection.on('error', function (err) {
  throw err;
});

mongoose.connection.once('open', function () {
  gridfs.init(mongoose.connection.db, mongoose.mongo);
});

Writing a file

You can write from a path String pointing to a file, a Stream.Readable object created from the fs module or a Buffer.

You can define your source as a String:

var source = '/path/to/the/file.ext';

As a Stream.Readable:

var source = fs.createReadStream('/path/to/the/file.ext');

Or as a Buffer:

var source = new Buffer('important buffer data here');

And then save it to GridFS with:

gridfs.write(source, function (err, fsfile) {
  if (err) {
    throw err;
  }

  /* Do whatever you want with your fsfile */
  console.log("The file %s named %d has a length of %d", fsfile._id, fsfile.filename, fsfile.length);
});

A common fsfile Object should look like this:

{
  _id: ObjectId,
  filename: String,
  contentType: String,
  length: Number,
  chunkSize: Number,
  uploadDate: Date,
  aliases: Object,
  metadata: Object,
  md5: String
}

Reading a file

To read a file you must provide a String than can be either a valid ObjectId or a file name.

So, you can define your file as an ObjectId:

var file = '55a52e49a562f0bb2627f38e';

Or as a file name:

var file = 'secret_document.docx';

And then get access to the file with:

gridfs.read(file, function (err, fsfile, rs) {
  if (err) {
    throw err;
  }

  /* Now you have your fsfile object and a nice read stream */
});

The rs parameter is a Stream.Readable object that can be piped, written or anything that Stream.Readable's can do.

Removing a file

To remove a file you must provide a String than can be either a valid ObjectId or a file name.

You can remove the file via it's ObjectId:

var file = '55a52e49a562f0bb2627f38e';

Or it's file name:

var file = 'secret_document.docx';

And then remove the file with:

gridfs.remove(file, function (err) {
  if (err) {
    throw err;
  }

  /* File has been removed */
});