Is there a nodejs module or example of how to make GridFS files accessible with WebDAV? - mongodb

Question

I have an existing node.js app where users have a library of files that are stored with GridFS. Each user has their own library. I would like to make the library mountable with WebDAV so that a user could manage their library from their desktop.
I have seen jsDAV used to access the filesystem but it is not clear how to extend it for use with a virtual file system. I found gitDav but it is not clear how to use it.
Is this even possible without starting from scratch?

Answer 1

I was looking to use jsDAV to make some resources available through WebDAV. Failing to find a working example, I studied the comments in the source and wrote one myself. jsDAV is a port from a PHP library. The Sabre manual is useful guide in general. One thing to remember is that since we're in an asynchronous environment, functions that return the results in PHP might have to invoke a callback function instead. This usually happens when the operation in question involves reading from the disk. The first parameter to the callback will always be an error object, which should be null when all goes well.
'use strict';
var crypto = require('crypto');
var jsDAV = require("jsDAV/lib/jsdav");
var jsDAVLocksBackendFS = require("jsDAV/lib/DAV/plugins/locks/fs");
var jsDAVFile = require("jsDAV/lib/DAV/file");
var jsDAVCollection = require("jsDAV/lib/DAV/collection");
var jsExceptions = require("jsDAV/lib/shared/exceptions");
var VirtualFile = jsDAVFile.extend(
{
initialize: function(name, buffer) {
this.name = name;
this.buffer = buffer;
},
getName: function() {
return this.name;
},
get: function(callback) {
callback(null, this.buffer);
},
put: function(data, type, callback) {
callback(new jsExceptions.Forbidden("Permission denied to change data"));
},
getSize: function(callback) {
callback(null, this.buffer.length);
},
getETag: function(callback) {
var shasum = crypto.createHash('sha1');
shasum.update(this.buffer);
var etag = '"' + shasum.digest('hex') + '"';
callback(null, etag);
},
getContentType: function(callback) {
callback(null, 'text/plain');
}
});
var VirtualDirectory = jsDAVCollection.extend(
{
initialize: function(name, children) {
this.name = name;
this.children = children;
},
getChildren: function(callback) {
var list = [];
for (var name in this.children) {
list.push(this.children[name]);
}
callback(null, list);
},
getChild: function(name, callback) {
var child = this.children[name];
if (child) {
callback(null, child);
} else {
callback(new jsExceptions.NotFound("File not found"));
}
},
childExists: function(name, callback) {
var exists = (this.children[name] !== undefined);
callback(null, exists);
},
getName: function() {
return this.name;
}
});
var children = {};
for (var i = 1; i <= 10; i++) {
var name = 'file' + i + '.txt';
var text = 'Hello world, #' + i;
children[name] = VirtualFile.new(name, new Buffer(text, 'utf8'));
}
var grandchildren = {};
for (var i = 66; i <= 99; i++) {
var name = 'beer' + i + '.txt';
var text = i + ' bottles of beer';
grandchildren[name] = VirtualFile.new(name, new Buffer(text, 'utf8'));
}
children['folder'] = VirtualDirectory.new('folder', grandchildren);
var root = VirtualDirectory.new(null, children);
var options = {
node: root,
locksBackend: jsDAVLocksBackendFS.new(__dirname + "/data")
};
var port = 8000;
jsDAV.createServer(options, port);

Answer 2

It looks like jsDAV is the only option. It is a port of a PHP library and it is not setup in such a way that you can use it like a normal node.js module. I found a few examples of server types that others have created to connect it with dropbox and couchdb.
I am now working on a server type that will work more like you would expect a node.js module to work. The next step will be making it play nice with npm. You can see my fork here.