Ruby on Rails：应用程序级过滤，每个模型中都有id

Question

I am doing this software for clubs where people can just sign in and add scores, players, teams etc. Now I of course have many clubs and for every model there is club_id column to identify that club. Is there some easier way to check for current club than writing something like this:

News.where("club_id = ?", @club_id)

I found it too hard to abstract this proplem so much that I could find any answer.

Answer 1

One way would be to make some basic class for your models:

class ClubStuff < ActiveRecord::Base
  self.abstract_class = true # <--- don't forget
  default_scope { where(club_id: Thread.current[:club_id]) }
end

and make your models out of it:

class News < ClubStuff

Then:

# in ApplicationController
before_filter { Thread.current[:club_id] = params[:club_id] }

I hope you got the idea.

Answer 2

Why create an extra id (club_id) when there is a default id attribute in every model in RoR? You can use this code

News.find(id).

If you still insist, then an alternative code is:

News.find_by_club_id(@club_id)

Answer 3

Well you could write some before filters in your controller. Using your Team example:

class TeamController < AC
  before_filter :get_club, :only => [ :index ]    # you can limit the filter to methods

  def index
    # because of the before filter you can access club here
    @teams = @club.teams
  end

  # ...

  private
  def get_club
    @club = Club.find(params[:club_id])
  end
end

This behavior could be moved into a module as well. See here for more information on filters.