MultiTenant is a Rails 3 plugin to help ease the development of web applications that utilise the database in a multi-tenant manner, and provide each end-user/account with their own subdomained version of the application.

This plugin is currently work in progess. Managing subdomains still to do..

Add MultiTenant to your Gemfile and run bundle install:

gem "multi_tenant", :git => 'git://github.com/virtualstaticvoid/multi_tenant.git', :branch => 'master'

Add multi_tenant_model to the primary model

class Account < ActiveRecord::Base
  multi_tenant_model
  has_many :properties
end

Any models that should be explicitly scoped to a multi_tenant_model require the belongs_to_tenant to be set

class Property < ActiveRecord::Base
  belongs_to_tenant :account
end

Property scoping will behave as normal unless a current account has been set:

Property.all
#> [#<Property account_id: 1>, #<Property account_id: 2>]
Account.current = Account.find(1)
Property.all
#> [#<Property account_id: 1>]

If the current account is set, instantiating new property records will automatically be assigned to the current account:

Property.new
#> <Property account_id: nil>

Account.current = Account.find(25)
Property.new
#> <Property account_id: 25>

If you want to have subdomained instances of the application:

class ApplicationController < ActionController::Base
  subdomain_by_multi_tenant_model :account
end

This basically tells the app to set the current account to Account.find_by_subdomain!(subdomain). Will Throw an exception if the account can't be set. Every subdomain will also have an independent session.

Alternatively, if you want to set the current account based on your own requirements, add a before_filter to your controller:

class ApplicationController < ActionController::Base

  multi_tenant_model :account
  before_filter :set_current_account
  
  private
  
  def set_current_account
    Account.current = <logic here for getting account>    
  end
end

The controller aspect is currently not tested in isolating in the plugin as I haven't gotten around to working out how to generate routes in rails 3 for test controllers. They'll be extracted out of the application I'm using this plugin for eventually but you'll probably want to write some in your application..

Copyright (c) 2010 [Mark Connell], released under the MIT license