如何填充嵌套对象？

Question

我正在尝试填充用户内的嵌套对象。我正在尝试使用EJS标记显示所有收到的消息，以及消息时间，主题行和作者。我只能填充给定消息的ID。 这是我的数据结构

User
  --threads
    --thread_id
  --messages
    --sent
      --message_id
    --recieved
      --message_id

这是我的模式：

var mongoose = require("mongoose");
var passportLocalMongoose = require("passport-local-mongoose");
var uniqueValidator = require('mongoose-unique-validator');

var UserSchema = mongoose.Schema({
    username: { type: String, required: true, unique: true },
    password: { type: String, required: true },
    first_name: { type: String, required: true },
    middle_initial: { type: String, required: true },
    last_name: { type: String, required: true },
    phone: { type: Number, required: true },
    address: { type: String, required: true },
    email: { type: String, required: true, unique: true },
    isManager: Boolean,
    isSysAdmin: Boolean,
    points_accrued: Number,
    threads: [
        {
            type: mongoose.Schema.Types.ObjectId,
            ref: "Thread"
        }
    ],
    messages: {
        sent: [{
            type: mongoose.Schema.Types.ObjectId,
            ref: "Message"
        }],
        recieved: [{
            type: mongoose.Schema.Types.ObjectId,
            ref: "Message"
        }],
    },
    id: {
        type: mongoose.Schema.Types.ObjectId,
        ref: "User"
    }
});

UserSchema.plugin(passportLocalMongoose);
UserSchema.plugin(uniqueValidator);

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

线程模式：

var mongoose = require("mongoose");

var threadSchema = mongoose.Schema({
    id: {
        type: mongoose.Schema.Types.ObjectId,
        ref: "Thread"
    },
    author: {
        id: {
            type: mongoose.Schema.Types.ObjectId,
            ref: "User"
        },
        name: { type: String, required: true }
    },
    recipient: {
        id: {
            type: mongoose.Schema.Types.ObjectId,
            ref: "User"
        },
        name: { type: String, required: true }
    },
    messages: [
        {
            type: mongoose.Schema.Types.ObjectId,
            ref: "Message"
        }
    ],
    subject: { type: String, required: true },
    date: { type: String, required: true },
    time: { type: String, required: true },
});

module.exports = mongoose.model("Thread", threadSchema);

最后是消息模式：

var mongoose = require("mongoose");

var messageSchema = mongoose.Schema({
    text: { type: String, required: true },
    subject: { type: String, required: true },
    date: { type: String, required: true },
    time: { type: String, required: true },
    author: {
        id: {
            type: mongoose.Schema.Types.ObjectId,
            ref: "User"
        },
        name: { type: String, required: true }
    }
});

module.exports = mongoose.model("Message", messageSchema);

现在这是我目前正在使用的GET路由，应该用来填充消息：**注意，我的代码中对所有模型都具有所有正确的require语句

// Gets messages for regular Employees, not Admins
router.get("/", middleware.isLoggedIn, function (req, res) {
    User
        .findById(req.user._id)
        .populate(/////IDK WHAT SHOULD GO HERE/////)
        .exec(function (err, foundUser) {
            if (err || !foundUser) {
                console.log("This is an error", err);
                req.flash("error", "User Not Found");
                res.redirect("back");
            } else {
                User.find({}, function (err, foundUsers) {
                    if (err || !foundUsers) {
                        console.log(err);
                        req.flash("error", "Users Not Found");
                        res.redirect("back");
                    } else {
                        res.render("users/messages", { users: foundUsers, user: foundUser });
                    }
                });
            }
        });
})

最后，我的EJS文件：

<hr>
        <%= user%>
        <% user.messages.recieved.forEach(function(message) {%>
            <p>
                <%= message%>
                <%= message.text%>
            </p>
        <% }); %>

所以在我的ejs中，再次显示的是ID，但是没有出现message.text。我尝试了许多不同的方法来显示message.text。这是我尝试过的：

.populate("messages") //DIDNT WORK


.populate({
    path: "messages",
    select: "sent recieved"
})                   //DIDNT WORK


.populate({
    path: "messages",
    select: "sent recieved",
    populate: {
        path: "sent",
        model: "Message",
        select: "text subject ect..."
    }
})  //DIDNT WORK

如果您能帮助我，并解释您给我的答案，我将非常感激！