为什么 Route.post() 需要一个回调函数但得到一个 [object Object]

Question

我正在尝试将我的文件保存在特定路径中并保存在 mongodb 中，这里我在route.js 中使用中间件uploadImg，但得到和 Error: Route.post() requires a callback function but got a [object Object]

这里有什么问题，请帮助我这里哪里错了。提前谢谢！！

config/imageUpload.js:-

  const multer = require("multer"),
  storage = multer.diskStorage({
     destination: function (req, file, cb) {
     cb(null, 'uploads')
  },
  filename: function (req, file, cb) {
     cb(null, file.fieldname + '-' + Date.now())
   }
  })
  const uploadImg = multer({storage: storage}).single('image');
     module.exports = {
       uploadImg: uploadImg,
     }
  return uploadImg;

controllers.js：

exports.addRoleFields = async (req, res) => {
  const rolesExist = Role.find({ roleType : req.body.roleType })
  if (rolesExist.length > 0){
    res.status(201).send({ message: "Role already exist", statusCode: "201" });
   }
  else {
  const rolesList = new Role ({     
    roleType : req.body.roleType,
    roleImg  : req.file.path,
  });
rolesList
.save(rolesList)   
  .then(data => {
    res.status(200).send({ data, statusCode: "200" });
  })
  .catch(err => {
    res.status(500).send({
      message: err.message || "Some error occurred while creating.",
      statusCode: "500"
    });
  })
 }
}

routes.js：

module.exports = app => {
 const roles = require("../controllers/roles.js");
 const  uploadImg  = require("../config/imageUpload");
    var router = require("express").Router();
    router.post("/addRole",uploadImg  ,roles.addRoleFields);
    app.use('/api/roles', router);
};

Answer 1

在您的 config/imageUpload.js 中，您正在导出一个包含您创建的中间件的对象。 您可以：

• 在 imageUpload.js 中直接导出中间件（更简单）

    const multer = require("multer"),
        storage = multer.diskStorage({
            destination: function(req, file, cb) {
                cb(null, 'uploads')
            },
            filename: function(req, file, cb) {
                cb(null, file.fieldname + '-' + Date.now())
            }
        })
    const uploadImg = multer({
        storage: storage
    }).single('image');
    module.exports = uploadImg

• 或者，改为通过在您的 routes.js 中解构中间件来导入

    module.exports = app => {
        const roles = require("../controllers/roles.js");
        const { uploadImg } = require("../config/imageUpload");
        var router = require("express").Router();
        router.post("/addRole", uploadImg, roles.addRoleFields);
        app.use('/api/roles', router);
    };