Created
March 11, 2012 21:48
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Simple has_many :through
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| ########### | |
| # Classes # | |
| ########### | |
| class Group < ActiveRecord::Base | |
| has_many :memberships, | |
| :class_name => 'GroupUser' | |
| has_many :users, | |
| :through => :memberships, | |
| :source => :user | |
| has_many :owners, | |
| :through => :memberships, | |
| :source => :user, | |
| :conditions => {'groups_users.role' => GroupUser::OWNER_ROLE} | |
| has_many :newbies, | |
| :through => :memberships, | |
| :source => :user, | |
| :conditions => {'groups_users.role' => GroupUser::NEWBIE_ROLE} | |
| end | |
| class User < ActiveRecord::Base | |
| has_many :group_memberships, | |
| :class_name => 'GroupUser', | |
| :dependent => :destroy | |
| has_many :groups, | |
| :through => :group_memberships | |
| end | |
| class GroupUser < ActiveRecord::Base | |
| OWNER_ROLE = 'owner' | |
| NEWBIE_ROLE = 'newbie' | |
| belongs_to :group | |
| belongs_to :user | |
| end | |
| ######## | |
| # So, I want a "group" to always have an owner, here's how I'm doing it now, | |
| # I'm not enamored of this approach | |
| ######## | |
| # Add an attr_accessor and a callback to the Group class | |
| class Group < ActiveRecord::Base | |
| # Same shit as above | |
| # New stuff | |
| attr_accessor :created_by | |
| after_create :set_owner | |
| private | |
| def after_create | |
| memberships.create(:user => created_by) do |m| | |
| m.role = GroupUser::OWNER_ROLE | |
| end | |
| end | |
| end | |
| # For Newbies, the shit is a little trickier, because I want to do | |
| # things like validate roles for adding newbies, send invitation | |
| # emails, etc. So, instead of trying to do all of that shit in | |
| # the join model, I created a new class | |
| class GroupNewbie | |
| extend ActiveModel::Callbacks | |
| include ActiveModel::Validations | |
| # Attributes | |
| attr_accessor :group_id, :created_by, :email, :user, :group | |
| # Bunch of validations | |
| # Bunch of callbacks | |
| def save | |
| _run_create_callbacks do | |
| GroupUser.create(:user => user, :group => group) do |gu| | |
| gu.role = GroupUser::NEWBIE_ROLE | |
| end | |
| end if valid? | |
| end | |
| end | |
| # Then, in the controller, I can just do: | |
| newb = GroupNewbie.new(:group_id => 1, :created_by => current_user, :email => 'newbie@example.com') | |
| if newb.save | |
| # blah | |
| else | |
| # worse blah | |
| end | |
| # So, that's where I'm at now. What I'd like to do... what feels most "Rails-ish" | |
| # is this: | |
| # Adding a newbie | |
| # This does create the GroupUser record, but it doesn't populate the 'role' attribute | |
| group = Group.find(params[:id]) | |
| group.newbies << User.find_by_email('newbie@example.com') | |
| # Adding a new group | |
| # This creates the Group record, but does NOT create the GroupUser record. Leading to | |
| # the code mentioned above | |
| group = current_user.groups.build(params[:group]) | |
| group.save | |
| # What do you think? |
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