responder_controller

Rails 3 responders wrap up as much crud controller code as possible without finding or mutating models on your behalf. This is a sensible cut-off for framework support, but it still leaves a fair amount of duplicate code in crud controllers. App developers are free to abstract more.

This is me abstracting more for my own apps. If it’s handy for you, go nuts.

Example

# app/models/post.rb
class Post < ActiveRecord::Base
  belongs_to :user

  scope :authored_by, lambda { |user_id| where(:user_id => user_id) }
  scope :recent, lambda { |num| order("updated_at DESC").limit(num.to_i) }
end

# app/controllers/posts_controller.rb
class PostsController < ApplicationController
  include ResponderController

  respond_to :html, :xml, :json

  # restrict to just the current user's posts
  scope { |posts| posts.authored_by current_user.id }
end

# Client-side
GET /posts.html             # renders Post.authored_by(your_id)
GET /posts.html?recent=10   # renders Post.authored_by(your_id).recent(10)
GET /posts/1.html           # renders post 1 if you authored it, or 404
PUT /posts/1.html           # update same
DELETE /posts/1.html        # or delete it

Point it at a different model class:

class ProfilesController < ApplicationController
  include ResponderController
  serves_model :user
end

Forbid a certain scope

class PostsController < ApplicationController
  include ResponderController
  serves_scopes :except => :authored_by # asking for it will 403
end

Or use a white list instead

class PostsController < ApplicationController
  include ResponderController
  serves_scopes :only => :recent
end

Serve resources in a namespace:

class PostsController < ApplicationController
  include ResponderController
  responds_within 'my-blog'
end

# Client-side
GET /my-blog/posts.html

A nested resource, using blocks for dynamic behavior:

class CommentsController < ApplicationController
  include ResponderController

  # Only get comments for the identified post
  scope do |comments|
    comments.where :post_id => params[:post_id]
  end

  # Nest the comments under the post
  responds_within do |comments|
    Post.find(params[:post_id])
  end
end

The same:

class CommentsController < ApplicationController
  include ResponderController
  children_of :post
end

Note on Patches/Pull Requests

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don’t break it in a future version unintentionally.
Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
Send me a pull request. Bonus points for topic branches.

Thanks

Thanks to SEOmoz (seomoz.org) for letting me build this at my desk in the afternoons instead of on the couch in the middle of the night ^_^.