node.js - 类型错误 : Cannot read property '_id' of undefined body-parser is installed and required

Question

当我创建新博客文章并尝试提交它时，出现以下错误:“TypeError: 无法读取未定义的属性 '_id'”

这是“id 未定义”的代码

// CREATE ROUTE
router.post("/", function(req, res){

// Sanitizes blog body to prevent  harmful content through it
req.body.blog.body = req.sanitize(req.body.blog.body);
  // get data from form and add to blogs array
  var title = req.body.title;
  var image = req.body.image;
  var body = req.body.body;
  var author = {
      id: req.user._id,
      username: req.user.username
  };


    var newBlog = { title: title, image: image, body: body, author: author};
    //Create blog
    Blog.create(newBlog, function(err, newlyCreated){
        //handle error if can't create post
        if(err){
            res.render("bposts/new");
            //otherwise post it and redirect back to Blog Posts
        } else {
            console.log(newlyCreated);
            res.redirect("/bposts");
        }
    });
});

此行触发错误:

var author = {
      id: req.user._id,
      username: req.user.username
  };

我还在下面发布了我的模型和 app.js。当我对这个主题进行研究时，似乎一切都导致无法解析 req.something.whateverPropertyTryingToParse，或者在我的例子中 req.user._id。我的正文解析器已安装并保存到 package.json 文件中，正如您将在我的 app.js 文件中看到的那样。我不知道为什么它无法解析 id。任何有关为什么会发生这种情况的帮助和解释都值得赞赏。

博客模型:

  var mongoose = require("mongoose");

// SCHEMA
var blogSchema = new mongoose.Schema({
    title: String,
    image: String,
    body: String,
    created: {type: Date, default: Date.now},
     author: {
      id: {
         type: mongoose.Schema.Types.ObjectId,
         ref: "User"
      },
      username: String
   },
   comments: [
      {
         type: mongoose.Schema.Types.ObjectId,
         ref: "Comment"
      }
   ]
});
//MODEL
module.exports = mongoose.model("Blog", blogSchema);

用户模型:

var mongoose = require("mongoose");
var passportLocalMongoose = require("passport-local-mongoose");

var UserSchema = new mongoose.Schema({
    username: {type: String, unique: true, required: true},
    password: String,
    // avatar: String,
    firstName: String,
    lastName: String,
    email: {type: String, unique: true, required: true},
    // resetPasswordToken: String,
    // resetPasswordExpires: Date,
    // isAdmin: {type: Boolean, default: false}
});

UserSchema.plugin(passportLocalMongoose);

module.exports = mongoose.model("User", UserSchema);

app.js

    var express = require("express"),
    app = express(),
    bodyParser = require("body-parser"),
    mongoose = require("mongoose"),
    expressSanitizer = require("express-sanitizer"),
    passport = require("passport"),
    cookieParser = require("cookie-parser"),
    LocalStrategy = require("passport-local"),
    flash = require("connect-flash"),
    session = require("express-session"),
    moment = require("moment"),
    User = require("./models/user"),
    // seedDB      = require("./seeds"),
    methodOverride = require("method-override");


// APP CONFIG
mongoose.connect("mongodb://localhost/blog", {useMongoClient: true});
//PRODUCTION CONFIG - LIVE URL GOES HERE!

app.set("view engine", "ejs");
app.use(express.static(__dirname + "/assets"));
app.use(bodyParser.urlencoded({extended: true}));
app.use(expressSanitizer());
app.use(methodOverride("_method"));
app.use(cookieParser('secret'));
//require moment
app.locals.moment = require('moment');
// seedDB(); //seed test data!


// PASSPORT CONFIGURATION
app.use(require("express-session")({
    secret: "It's a secret to everyone!!",
    resave: false,
    saveUninitialized: false
}));

app.use(flash());
app.use(passport.initialize());
app.use(passport.session());
passport.use(new LocalStrategy(User.authenticate()));
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());

app.use(function(req, res, next){
   res.locals.currentUser = req.user;
   res.locals.success = req.flash('success');
   res.locals.error = req.flash('error');
   next();
});


// REQUIRE ROUTES
var commentRoutes = require("./routes/comments"),
    bpostRoutes = require("./routes/bposts"),
    indexRoutes = require("./routes/index");


//USE ROUTES
app.use("/", indexRoutes);
app.use("/bposts", bpostRoutes);
app.use("/bposts/:id/comments", commentRoutes);


//RUN SERVER
app.listen(process.env.PORT, process.env.IP, function(){
   console.log("The Server Has Started!");
});


//MIDDLEWARE
     var Comment = require('../models/comment');
    var Blog = require('../models/blog');
    module.exports = {
      isLoggedIn: function(req, res, next){
          if(req.isAuthenticated()){
              return next();
          }
          req.flash('error', 'You must be signed in to do that!');
          res.redirect('/login');
      },
      checkUserBlog: function(req, res, next){
        Blog.findById(req.params.id, function(err, foundBlog){
          if(err || !foundBlog){
              console.log(err);
              req.flash('error', 'Sorry, that Blog does not exist!');
              res.redirect('/bposts');
          } else if(foundBlog.author.id.equals(req.user._id) || req.user.isAdmin){
              req.Blog = foundBlog;
              next();
          } else {
              req.flash('error', 'You don\'t have permission to do that!');
              res.redirect('/bposts/' + req.params.id);
          }
        });
      },
      checkUserComment: function(req, res, next){
        Comment.findById(req.params.commentId, function(err, foundComment){
           if(err || !foundComment){
               console.log(err);
               req.flash('error', 'Sorry, that comment does not exist!');
               res.redirect('/bposts');
           } else if(foundComment.author.id.equals(req.user._id) || req.user.isAdmin){
                req.comment = foundComment;
                next();
           } else {
               req.flash('error', 'You don\'t have permission to do that!');
               res.redirect('/bposts/' + req.params.id);
           }
        });
      },
      isAdmin: function(req, res, next) {
        if(req.user.isAdmin) {
          next();
        } else {
          req.flash('error', 'This site is now read only thanks to spam and trolls.');
          res.redirect('back');
        }
      },
      isSafe: function(req, res, next) {
        if(req.body.image.match(/^https:\/\/images\.unsplash\.com\/.*/)) {
          next();
        }else {
          req.flash('error', 'Only images from images.unsplash.com allowed.\nSee https://youtu.be/Bn3weNRQRDE for how to copy image urls from unsplash.');
          res.redirect('back');
        }
      }
    };

Answer 1

不应该吗

var author = {
  id: req.body.user._id,
  username: req.body.user.username
 };

您能显示您要发布的数据的格式吗？