Question

For example, one user has joined many group; and one group has many user members. Now I get a user object and a group object, I want to know whether this user is a member of this group.

I can see some methods, but still wandering whether there is a better way?

Answer 1

So, if i understand your question, what you have is something like:

class User < ActiveRecord::Base
  has_many :groups, :though => :user_members

class Group < ActiveRecord::Base
  has_many :users, :though => :user_members

And you want to know if a user is a member of a specific group.

So, given something like:

u = User.first
g = Group.first

Just do:

u.groups.include? g

Thats all there is to it!

ian.