Join chat by code

To join chat it is need to verify:

• the “invitation code”
• how many users are using chat

After verification “user token” is generated and system chat ready message is registered.

Verification:

db.chats.findOne({
  $and: [
    {_id: ObjectId("543e33a2e3ce324d374246fc")},
    {status: "draft"}
  ]},
  {_id: 1}
);

In case of null result - “invitation code” is invalid otherwise - checking users_tokens number. Such number should be 1.

Next generate “user token”, update chat status and register system message for “chat creator”. To add new message it should use “$push” operator:

var user_token_joiner = ObjectId();
var message_ready = {
  "_id" : ObjectId(),
  “user_token”:  user_token_joiner,
  "msg" : "Talker was successfully joined to chat",
  "system" : true
  };

  db.chats.update(
    {_id: ObjectId("543e33a2e3ce324d374246fc")},
    {$set: {status: "ready"},
    $push: {user_tokens: user_token_joiner},
    $push: {"messages": message_ready}
  }
);