node.js - 如何在 NodeJS/Multer 中以相同的形式发送字段和文件？

Question

我的问题是当我发布到/new 时无法获取 req.body 和 req.file 对象，但一切正常，文件正在上传到我的文件夹中。我只是无法访问 req.body 和 req.file 对象。当我在控制台中记录 req.body 时，它返回 [object Object]，对于​​ req.file，它记录未定义。

我做了一些研究，发现您无法使用 body-parser 对 multipart/form-data 进行编码，但我需要它，因为没有它我无法发送文件。

var router = require('express').Router(),
    multer = require('multer'),
    path = require('path'),
    passport = require('passport'),
    middleware = require('../middleware'),
    User = require('../models/User'),
    Ad = require('../models/Ad');

// Storage setup
var storage = multer.diskStorage({
  destination: './public/uploads/',
  filename: function(req, file, done) {
    done(null, file.fieldname + '-' + Date.now() + path.extname(file.originalname));
  }
});

// Upload setup
var upload = multer({
  storage: storage,
  limits: {
    fileSize: 3000000
  }
}).single('banner');

// Check file type
function checkFileType(file, callback) {
  // Allowed extensions
  var fileTypes = /jpeg|jpg|png|gif/;
  // Check extention
  var extname = fileTypes.test(path.extname(file.originalname).toLowerCase());
  // Check mime type
  var mimeType = fileTypes.test(file.mimetype);

  if (mimeType && extname) {
    return callback(null, true);
  }
  callback(null, false);
}

router.get('/new', middleware.isLoggedIn, function(req, res) {
  res.render('new');
});

router.post('/new', middleware.isLoggedIn, function(req, res) {
  var adObj = {
    owner: req.user,
    url: req.user.url,
    paymentType: req.body.paymentType,
    transactionId: '',
    banner: ''
  };

  if (adObj.paymentType === 'paid') {
    adObj.transactionId = req.body.transactionId;
  }

  upload(req, res, function(err) {
    if (err) {
      req.flash('error', err.message);
      return res.redirect('/new');
    }
    adObj.banner = '/uploads/' + req.file.filename;
  });

  var ad = new Ad(adObj);
  ad.save();

  req.flash('success', 'Successfully added new ad.');
  res.redirect('/');
});

<form class="main-form" action="/new" method="POST" enctype="multipart/form-data">
      <input type="url" name="url" placeholder="Website URL" required>
      <select class="select-ad-type" name="paymentType">
        <option value="free" selected>Free Ad</option>
        <option value="paid">Sponsored Ad - $10</option>
      </select>
      <div class="transaction-section">
        <p>Send $10 to example@gmail.com and type your transaction id below. Your ad will be displayed in the "SPONSORED ADS" section in less than 24 hours.</p>
        <input type="text" name="transactionId" placeholder="Transaction Id">
      </div>
      <input type="file" name="banner" required>
      <button><i class="fa fa-plus" aria-hidden="true"></i> SUBMIT</button>
    </form>

Answer 1

您收到错误是因为您试图在 multer 进行实际解析之前访问这些值。您正确地指出 body-parser 不适用于 multipart-data，但在 multipart-data 表单类型中，multer 可以解析 file 和 form 中的其他字段，这就是为什么我们可以同时访问 req.file 和 请求正文。

确保在 upload(req, res, function(err) {//req.body and req.file })

中访问它

此外，还有一个与异步代码相关的问题。

解决方法:

router.post('/new', middleware.isLoggedIn, function(req, res) {
    upload(req, res, function(err) {
       if (err) {
          req.flash('error', err.message);
          return res.redirect('/new');
       }

       var adObj = {
          owner: req.user,
          url: req.user.url,
          paymentType: req.body.paymentType,
          transactionId: '',
          banner: ''
       };

       if (adObj.paymentType === 'paid') {
         adObj.transactionId = req.body.transactionId;
       }

       adObj.banner = '/uploads/' + req.file.filename;

       var ad = new Ad(adObj);
       ad.save();

       req.flash('success', 'Successfully added new ad.');
       return res.redirect('/');
    });
});