Serving Temporary Files with NodeJs - node.js

Question

I am building a NodeJs SOAP client. Originally, I imagined the server (ie the node SOAP client) would allow downloading documents through a REST API (the REST API is authenticated). After a good deal of time on Google and SO, looks like that is not possible.
That means when a document download is requested, I'll have to make a SOAP call for the document and return a URL to the REST client via AJAX.
In order to do this I'll need to:
Temporarily create a file in Node
get its URL and return to web client
When the file is requested and response is sent, delete the file (for security purposes)
Here are my questions:
Is there already a framework that does this? the temp module might be an option, but really I'd like to delete after every request, not after a time period.
If not, can I do this just using the NodeJs File System, and Express static module? Basically we would modify the static module to look like this:
return function static(req, res, next) {
if ('GET' != req.method && 'HEAD' != req.method) return next();
var path = parse(req).pathname;
var pause = utils.pause(req);
/* My Added Code Here */
res.on('end', function(){
// delete file based on req URL
})
/* end additions */
function resume() {
next();
pause.resume();
}
function directory() {
if (!redirect) return resume();
var pathname = url.parse(req.originalUrl).pathname;
res.statusCode = 301;
res.setHeader('Location', pathname + '/');
res.end('Redirecting to ' + utils.escape(pathname) + '/');
}
function error(err) {
if (404 == err.status) return resume();
next(err);
}
send(req, path)
.maxage(options.maxAge || 0)
.root(root)
.hidden(options.hidden)
.on('error', error)
.on('directory', directory)
.pipe(res);
};
Is res.on('end',... vaild? Alternatively,should I create some middleware that does this for URLs pointing to the temporary files?

Answer 1

Found two SO questions that answer my question. So apparently we don't need to use the express.static middleware. We just need the filesystem to download a file:
app.get('/download', function(req, res){
var file = __dirname + '/upload-folder/dramaticpenguin.MOV';
res.download(file); // Set disposition and send it.
});
If we want to stream and then delete follow:
app.get('/download', function(req, res){
var stream = fs.createReadStream('<filepath>/example.pdf', {bufferSize: 64 * 1024})
stream.pipe(res);
var had_error = false;
stream.on('error', function(err){
had_error = true;
});
stream.on('close', function(){
if (!had_error) fs.unlink('<filepath>/example.pdf');
});

Answer 2

If you are visiting this SO page after Dec 2015, you may find that the previous solution isn't working (At least it isn't working for me). I found a different solution so I thought I would provide it here for future readers.
app.get('/download', function(req, res){
res.download(pathToFile, 'fileNameForEndUser.pdf', function(err) {
if (!err) {
fs.unlink(path);
}
});
});