使用Mongoose更新数组中的项目？

Question

I'm trying to update a single "todo" item in an array of todos stored in a specific user's todos array. A typical user may look something like this:

{ isAdmin: false,
  _id: 5cefe9b72efc1c19a0318233,
  username: 'a',
  email: 'aaaaa@gmail.com',
  todos:
    [ { day: 'Monday',
        completed: false,
        _id: 5cf10e7fba969c4be4d356db,
        name: 'asdf',
        createdDate: 2019-05-31T11:22:39.423Z,
        __v: 0 },
      { day: 'Monday',
        completed: false,
        _id: 5cf10e8bba969c4be4d356dc,
        name: 'pp',
        createdDate: 2019-05-31T11:22:51.248Z,
        __v: 0 }],
  __v: 12 }

When a user creates a todo, the todo is created with another Todo model and pushed into the user's todos array. At first, I tried simply finding and updating the single todo with:

db.Todo.findOneAndUpdate({_id: req.params.todoId}, req.body, {new: true})
   .then(function(updatedTodo) {
       res.json(updatedTodo);
   })
   .catch(function(err) {
       res.send(err);
   })

...and it seems to update the todo within the Todos collection, but it doesn't update the todo that's nested in the user's "todos" array. So, I thought I'd resort to first finding the user and updating the id of the specific todo like so:

User.findById(req.user._id, function(err, user) {
    if (err) {
        console.log(err);
    } else {
        user.todos.forEach(function(todo) {
            if (todo._id == req.params.todoId) {
                todo.completed = !todo.completed;
            }
    }
});

...but again, it doesn't seem to actually update the todo nested in the User's "todos" array. I'm a bit lost here and not sure where to go. Any help would be extremely appreciated.

Answer 1

In case of User.findById() , is not enough to change todo.completed value. You have to save it as well. For example:

User.findById(req.user._id)
.then(user => {
    user.todos.forEach(function(todo) {
        if (todo._id === req.params.todoId) {
            todo.completed = !todo.completed;
        }
    })
    return user.save();
})
.then(result => {
   res.json(result);
})
.catch(function(err) {
    res.send(err);
})

Answer 2

You can use async/await for this.

user = await User.findById(req.user._id);
user.todos[user.todos.findIndex(i=>i._id==="todos id")].complated = true;
user.save();

or

User.findById(req.user._id, function(err, user) {
   if (err) {
      console.log(err);
   } else {
      user.todos.forEach(function(todo,index) {
         if (todo._id === req.params.todoId) {
            user.todos[index].completed = true;
         }
      User.updateOne({_id:req.user._id},user).exec();
}
});