use async - await with socket.io nodejs

Question

I'm developing a web application using nodejs socket.io and angular 9. In my backend code I have written sockets in socket.connect.service. Follows is a socket I'm using

socket.on('request-to-sit-on-the-table', async function (data, callback) { //Previously Register
    let table = persistence.getTable(tableToken);
    if (typeof table === 'undefined') {
        let errMsg = 'This table does not exists or already closed.'
        callback(prepareResponse({}, errMsg, new Error(errMsg)));
        return;
    }
    //TODO: Get the displayName from the token.
    let guest = await guestUserService.getGuestUserByPlayerToken(JSON.parse(data.userToken));***//Here is the issue***
    // let displayName = 'DisplayName-' + guest;
    let displayName = 'DisplayName-' + Math.random();

    //TODO: Check whether the seat is available

    // If the new screen name is not an empty string
    let isPlayerInCurrentTable = persistence.isPlayerInCurrentTable(tableToken, userToken);
    if (displayName && !isPlayerInCurrentTable) {
        var nameExists = false;
        let currentPlayersTokenArr = persistence.getTableObjectPlayersToken(table)
        for (var token in currentPlayersTokenArr) {
            let gamePlayer = persistence.getPlayerPlayer(currentPlayersTokenArr[token])
            if (typeof gamePlayer !== "undefined" && gamePlayer.public.name === displayName) {
                nameExists = true;
                break;
            }
        }
        if (!nameExists) {
            //Emit event to inform the admin for requesting to sit on the table.
            let ownerToken = persistence.getTableObjectOwnerToken(table);
            let ownerSocket = persistence.getPlayerSocket(ownerToken);
            ownerSocket.emit('requested-to-sit', {
                seat: data.seat,
                secondaryUserToken: userToken,
                displayName,
                numberOfChips: envConfig.defaultNumberOfChips
            });
            callback(prepareResponse({userToken}, 'Player connected successfully.'));
        } else {
            callback(prepareResponse({}, 'This name is already taken'));
        }
    } else {
        callback(prepareResponse({}, 'This user has already joined to a game. Try clear caching'));
    }

});

In my code I'm getting data from another code in guest.user.service. But I get undefined to the value of "guest" Follows are the methods I have used in guest.user.service

exports.findById = (id) => {
    return new Promise(function(resolve, reject) {
        guestUserModel.findById(id, (err, data) =>{
            if(err){
                reject(err);
            } else {
                resolve(data);
            }
        });
    });
};
exports.getGuestUserByPlayerToken = (playerToken) => {
    var player = playerService.findOne({ token: playerToken })
        .then(function (data) {
            return self.findById(data.guestUser._id.toString());
        })
        .then(function (guestUser) {
            return guestUser.displayName;
        })
        .catch(function (err) {
            throw new Error(err);
        })
};

Although I get my displayName for the return value It is not passed to the "guest" in my socket.Is there any syntax issue to get data as I'm using promises.please help

return the player on second function. – Vahid Alimohamadi Jun 30 '20 at 12:46 — Vahid Alimohamadi, Jun 30 '20 at 12:46
R u using mongoose? or Sequelize? – Vahid Alimohamadi Jun 30 '20 at 12:47 — Vahid Alimohamadi, Jun 30 '20 at 12:47

score 0 · Accepted Answer · answered Jun 30 '20 at 12:53

0


exports.getGuestUserByPlayerToken = async playerToken => {
   try {
     let player = await playerService.findOne({token:playerToken});
     return playerService.findById(player.guestUser._id)
   } catch(error) {
     console.log(error);
     return null;
   }
};

This is just handle error on awaited promise not returned one. You need to handle that in caller side.

answered Jun 30 '20 at 12:53

Vahid Alimohamadi

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Oh wow that helped me a lot. This is the answer. Thank You so much – Sahan Thilakarathna Jul 02 '20 at 03:01

use async - await with socket.io nodejs

1 Answers1