node.js - Cast to ObjectId failed for value \"[object Object]\" at path \"players\" -

i'm starting out mongoose , mongodb. i've tried find here on stackoverflow, however, i'm lost not know problem is.

i have following 2 models, reside in 2 different files:

var userschema = require('mongoose').model('user').schema; var tournamentschema = mongoose.schema({     tournamentname: string,     nrofplayers: string,     players: [{ type: mongoose.schema.types.objectid, ref: userschema }],     openforleagues: {         leagues: []     },     edition: string,     description: string,     startdate: date,     enddate: date,     starthour: string,     prize: boolean,     sponsors: string,     ingamechatchannel: string,     twitchstreamchannel: string });  module.exports = mongoose.model('tournament', tournamentschema);  var userschema = mongoose.schema({      local: {         nickname: string,         battlenetid: string,         email: string,         password: string,         race: string,         league: string,         role: string,         website: string     } });  module.exports = mongoose.model('user', userschema); 

inside routes.js file, following:

app.post('/signup-tournament/:_id/:userid', isloggedin, function(req, res) {     var playerid = req.params.userid;     var nickname = req.user.local.nickname;      console.log(objectid.isvalid(req.params.userid)); //true     console.log(objectid.isvalid(req.params._id)); //true     if (objectid.isvalid(playerid) && objectid.isvalid(req.params._id)) {         tournament.findbyidandupdate(req.params._id, {             $pushall: {                 players: {                     values: [playerid, nickname]                 }             }         }, function(err, tournament) {             if (err)                 res.send(err)             else                 res.redirect('/signup-tournament/' + req.params._id + req.params.userid);         });     } }); 

when post, following error:

{     "message": "cast objectid failed value \"[object object]\" @ path \"players\"",     "name": "casterror",     "type": "objectid",     "value": [{         "values": ["53e340b3afb9657f0dbcf994", "cristidrincu"]     }],     "path": "players" } 

i not understand why there cast error when ids validated using objectid.isvalid()... i've spent 2 days trying figure on own, please :) thank you!

you're trying perform findbyidandupdate operation against tournamentschema. problem in following code:

tournament.findbyidandupdate(req.params._id, {   $pushall: {     players: {       values: [playerid, nickname]     }   } }) 

players should contain user objects, should either player's _id (hex string or objectid), or valid user object _id field.

but you're trying push invalid object { values: [playerid, nickname] } instead.

here how operation should look:

tournament.findbyidandupdate(req.params._id, {   $pushall: {     players: [playerid]   } }) 

n.b. not sure nickname mean in example, doesn't valid objectid, removed it.