Accessing the id of a recently created record & allowing for duplicates

Question

I'm having trouble with has_many through: models.

What I'd like to do is create 2 person chat rooms in my model. Therefore, users has_many chats and has_many messages through chats.

How do I access a recently created id and also allow for that id to be non-unique? Also, do I have the right setup for what I am trying to do?

@u = User.find_by_id(1)
@u.chats.new.save <--How to get this chat id to associate with another user id?

my models:

class User < ActiveRecord::Base
    has_many :chats
    has_many :messages, through: :chats
end

class Chat < ActiveRecord::Base
    belongs_to :user
    belongs_to :message
end

class Message < ActiveRecord::Base
    has_many :chats
    has_many :users, through: :chats
end

Answer 1

This is a tough one - we have implemented something similar recently using the following setup:

#app/models/user.rb
Class User < ActiveRecord::Base
    #Chats
    def messages
        Chat.where("user_id = ? OR recipient_id = ?", id, id) # -> allows you to call @user.chats.sent to retrieve sent messages
    end
end

#app/models/chat.rb #- > id, user_id, recipient_id, message, read_at, created_at, updated_at
Class Chat < ActiveRecord::Base
    belongs_to :user
    belongs_to :recipient, class_name: "User", foreign_key: "recipient_id"

    #Read
    scope :unread,  ->(type) { where("read_at IS #{type} NULL") }
    scope :read,    ->       { unread("NOT") }

    #Sent
    scope :sent,     -> { where(user_id: id) }
    scope :received, -> { where(recipient_id: id) }
end

This setup makes every chat "owned" by a particular user. This is done when you create a message, and represents the sender. Every message has a single recipient, which you can see with recipient_id

So you'll be able to send new messages to users like this:

@chat = Chat.new(chat_params)

def chat_params
   params.require(:chat).permit(:user_id, :recipient_id, :message)
end

This will be okay for a single chat room (I.E single message transcript between two users -- private messaging etc).

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Can you explain how your chat rooms need to work? For example, if you only have two-way chats, surely you can use my above code? However, I feel it's not right; and I therefore want to refactor or you to accommodate multiple chat rooms

Answer 2

I'm sure there's a better way to do this, but this should give you your desired results.

@u = User.find(1) # You can use "find" instead of "find_by_id"
(@chat = @u.chats.new).save
@chat.users << User.find(x) # However you want to get the other user in the chat