单独文件

Question

我能够将一个非常简单的中间件（isAuthenticated）移动到外部中间件文件，但是我更难以将我的multer上传移动。我刚学会了如何将它们移动到单独的文件中，所以它可能是显而易见的。

routes/index.js
var middleware = require('../middleware/common');
var isAuthenticated = middleware.isAuthenticated;
var upload = middleware.multerSetup;
...

router.post('/updateuser',
    upload,
...,
    function (req, res, next) {
        res.redirect('/dashboard');
    }
);

-

//middleware/common.js
var multer = require('multer');


Middleware = {
        //Checks whether user is logged in
    isAuthenticated: function(req,res,next){
            if(req.isAuthenticated()){
                return next();
            }
            req.flash('auth',"You do not have the proper permissions to access this page");
            res.redirect('/');
        },
    multerSetup: function(req,res,next){
        var storage = multer.diskStorage({
            destination: function (req, file, cb) {
                cb(null, './public/uploads/')
            },
            //detects file type, then adds extension to match file type
            filename: function (req, file, cb) {
                var ext = "";
                switch(file.mimetype){
                    case 'image/png':
                        ext = '.png';
                        break;
                    case 'image/jpeg':
                        ext = '.jpeg';
                        break;
                    default:
                        ext = '';
                }
                cb(null, Date.now() + ext); //Appending .jpg
            }
        });


        var upload = multer({storage:storage, fileFilter: function (req, file, cb) {
            var acceptedExt = ['.png','.jpg','.gif','.bmp'];
            if (req.hasOwnProperty('file') && acceptedExt.indexOf(path.extname(file.originalname))=== -1) {
                return cb(new Error('Image type not allowed: ' + path.extname(file.originalname)));
            }

            cb(null, true)
        }});

        return upload.single('upl');
     }

};

module.exports = Middleware;

错误：

routes\index.js:108
    upload.single('upl'), 
           ^

TypeError: upload.single is not a function
    at Object.<anonymous> (C:\Users\Tyler\WebstormProjects\volunteer\volunteerApp\routes\index.js:108:12)

Answer 1

您正在设置您的multer中间件错误。您的Middleware.multerSetup是一个中间件函数，然后调用upload.single来设置multer（然后调用multer，然后请求挂起）。将您的multer上传设置移到自定义中间件之外，让模块从upload.single导出返回函数。

示例：

Middleware = {
   ...
   multerSetup: upload.single('upl')
   ...
}

Answer 2

知道了！只需要将routes / index.js中的上传定义为函数。

var upload = middleware.multerSetup();