Node.js 如何在nodejs中将上传的图片从multer保存到mongodb

我需要将用户信息从注册表保存到mongodb。 除了图像文件外，其他一切都正常工作。我正在使用Multer将图像从表单上传到服务器

还可以在用户登录后在配置文件页面中显示该图像

代码如下：

signup.ejs：

<form action="/signup" method="post" enctype="multipart/form-data">
    <label for>Profile Picture</label>
    <input type="file" name="image"><br><br>
    <label for>Name</label>              
    <input type="text" name="name"><br><br>
    <label for>Email</label>              
    <input type="email" name="email"><br><br>
    <label for>Password</label>  
</form> 

图像上载到/uploads文件夹中

但是如何获取该图像并将其保存在mongodb中。我正在使用passport.js，下面是保存帖子数据的代码

UserModel.js：

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var userSchema = new Schema({
  image: { 
      data        : Buffer, 
      contentType : String 
  },
  name: {
      type: String,
  },
  email: {
      type: String,
  },
  password: {
      type: String,
  }
});

passport.js：

passport.use('local-signup', new LocalStrategy({
    usernameField : 'email',
    passwordField : 'password',
    passReqToCallback : true
},
function(req, email, password, done) {
    User.findOne({ 'email' :  email }, function(err, user) {
        if (err) {
            //errorLogger.error(err);
            return done(err);
        }

        if (user) {
            return done(null, false, req.flash('signupMessage', 'Email already exists.'));
        } else {
            var newUser = new User();
            //newUser.image = "dont know how to get image from /uploads" 
              newUser.name = req.body.name;
              newUser.email = req.body.email;
              newUser.password = req.body.password;

              newUser.save(function(err) {
                if (err)
                    throw err;
                return done(null, newUser, req.flash('signupMessage', 'User created'));
            });
        }
});

---

您可以创建自己的中间件来处理上载中间件并获取文件名

我还建议在上传的图片末尾添加一些随机字符串，以防止同名图片出现

app.post('/signup', middleware , passport.authenticate('local-signup', {
    successRedirect : '/login', 
    failureRedirect : '/',
    failureFlash : true 
}));

中间件

function middleware(req, res, next) {

    var imageName;

    var uploadStorage = multer.diskStorage({
        destination: function (req, file, cb) {
            cb(null, './uploads');
        },
        filename: function (req, file, cb) {
            imageName = file.originalname;
            //imageName += "_randomstring"
            cb(null, imageName);
        }
    });

    var uploader = multer({storage: uploadStorage});

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

    uploadFile(req, res, function (err) {
        req.imageName = imageName;
        req.uploadError = err;
        next();
    })
}

并且您可以使用req.imageName

passport.use('local-signup', new LocalStrategy({
    usernameField : 'email',
    passwordField : 'password',
    passReqToCallback : true
},
function(req, email, password, done) {
    User.findOne({ 'email' :  email }, function(err, user) {
        if (err) {
            //errorLogger.error(err);
            return done(err);
        }

        if (user) {
            return done(null, false, req.flash('signupMessage', 'Email already exists.'));
        } else {
            var newUser = new User();
              newUser.image = req.imageName;
              newUser.name = req.body.name;
              newUser.email = req.body.email;
              newUser.password = req.body.password;

              newUser.save(function(err) {
                if (err)
                    throw err;
                return done(null, newUser, req.flash('signupMessage', 'User created'));
            });
        }
});

---

如果您使用的图像格式为“jpeg/png”，并且小于16mb，那么您可以使用github repo，它是一个模块，可以帮助您轻松地将图像保存到mongodb，并且没有GRIDFS的复杂性，但是如果您的文件大于16mb，则需要使用GRIDFS

这是用于小于16MB图像的github repo的链接（也适用于react）

---

为什么在注册前上传图像？？通常在注册和电子邮件确认后，从第二个表单或帐户管理上传图像。

passport.use('local-signup', new LocalStrategy({
    usernameField : 'email',
    passwordField : 'password',
    passReqToCallback : true
},
function(req, email, password, done) {
    User.findOne({ 'email' :  email }, function(err, user) {
        if (err) {
            //errorLogger.error(err);
            return done(err);
        }

        if (user) {
            return done(null, false, req.flash('signupMessage', 'Email already exists.'));
        } else {
            var newUser = new User();
              newUser.image = req.imageName;
              newUser.name = req.body.name;
              newUser.email = req.body.email;
              newUser.password = req.body.password;

              newUser.save(function(err) {
                if (err)
                    throw err;
                return done(null, newUser, req.flash('signupMessage', 'User created'));
            });
        }
});