如何使用multer上传文件/在表格数据中过帐？

Question

This is the productsModel.js file

'use strict';
var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var productsSchema = new Schema({
      name: {
        type: String,
        required: true
      },
      cost: {
          type: Number
      },
      product_imagePaths: [{
          type: String
      }]
    });

module.exports = mongoose.model('Products', productsSchema);

And this is the code of my productsController.js

var mongoose = require('mongoose'),
Products = mongoose.model('Products');


exports.uploadProducts = function(req,res) {
    var new_product = new Products(req.body)
    new_product.save(function(err,product){
        if(err) {
            res.send(err);
         }
         res.status = 200;
         res.json({
            "status":"success"
         });
     }); 
};

productsRoutes.js

'use strict';
module.exports = function (app) {
  var productsController = require('../controllers/productsController');

  app.route('/products')
    .get(productsController.fetchAllProducts)
    .post(productsController.uploadProducts);
};

In my server.js

// mongoose instance connection url connection
mongoose.Promise = global.Promise;
var db = mongoose.connect('mongodb://localhost/abcd', {
    useMongoClient: true
}); 


 // body parser middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true }));

// route
var userRoutes = require('./api/routes/userRoutes');
var aboutUsRoutes = require('./api/routes/aboutusRoutes');
var productsRoutes = require('./api/routes/productsRoutes');
userRoutes(app);
aboutUsRoutes(app);
productsRoutes(app);

Now this works when I'm using x-www-form-urlencoded . But since I want to upload a file via the Post method(uploadProducts in productsController.js), it can be done only via form-data . However, it doesn't work with form-data . I read that multer can be used for form-data upload, but I'm clueless as to how to use it in the following methodology.

Answer 1

You want to use multer as middleware before calling your uploadProducts function.

Here is an example setup for productRoutes.js

'use strict';
 const multer = require('multer')
 const storage = multer.memoryStorage()
 const upload = multer({
      storage: storage,
      limits: {
        fileSize: 5000000,
        files: 1
      }
    })
module.exports = function (app) {
  var productsController = require('../controllers/productsController');

  app.route('/products')
    .get(productsController.fetchAllProducts)
    .post(upload.single('img'), productsController.uploadProducts);
};

This will create a Buffer of your image which you can access in your productsController.js with req.file.buffer .

Note that upload.single is a built in function for multer . Read more about other functions here . Also img needs to match the name of your input field, ie <input type="file" name="img">

This is just one of many one ways to do it. Hope it helps!