expressjs - how to require multer in another file

Question

i use multer according to it's readme file in github
it's readme said call multer in middleware like this:

app.js

var multer = require('multer')
app.post('/upload', upload.single('image'), function(req, res){})

but i defined my function(req, res) in another file - post.js - and my code in app.js looks like this:

app.post('/upload', upload.single('image'), post.new)

how can i require multer only on post.js, almost like this:

post.js

 var multer = require('multer')
 module.exports.new = function(req, res){
     //access to req.file
 }

app.js

 app.post('/upload', post.new)

Answer 1

I can think of two ways.

Firstly, you could expose new as an array:

module.exports.new = [upload.single('image'), function(req, res) {
    ...
}];

Secondly, you could use multer within your function:

var imageUpload = upload.single('image');

module.exports.new = function(req, res) {
    imageUpload(req, res, function(err) {
        // Put the rest of your code here
    });
};

In this second approach we're just invoking the multer middleware function ourselves, passing it our own function to use as the next callback. There's a little bit more information about doing this at https://github.com/expressjs/multer#error-handling though it describes the technique in a slightly different context.