gistfile1.builder

# RESTful API
#
# +--------+-------------------+---------+---------+----------+-----------+
# | METHOD   PATH              | ACTION  | PAYLOAD | TEMPLATE | REDIRECT  |
# + -------+-------------------+---------+---------+----------+-----------|
# | GET    | /orders           | index   |         | index    |           |
# | GET    | /orders/new       | new     |         | edit     |           |
# | GET    | /orders/4;edit    | edit    |         | edit     |           |
# | GET    | /orders/4         | show    |         | show     |           |
# + -------+-------------------+---------+---------+----------+-----------+
# | POST   | /orders           | create  | yes     |          | show/edit |
# | POST   | /orders/4;update  | update  | yes     |          | show/edit |
# | POST   | /orders/4;destroy | destroy | yes     |          | index     |
# + -------+-------------------+---------+---------+----------+-----------+
# | PUT    | /orders/4         | update  | yes     |          | show/edit |
# + -------+-------------------+---------+---------+----------+-----------+
# | DELETE | /orders/4         | destroy | yes     |          | index     |
# + -------+-------------------+---------+---------+----------+-----------+

REST = %w[ index new edit show create update destroy ]
THEN = {
  :create  => :show,
  :update  => :show,
  :destroy => :index,
}

def self.restful ; @restful = true; end
def self.restful?; @restful       ; end

def rest(info = @info.first)
  http = @env['REQUEST_METHOD']

  # determine which action to perform
  @action = case http
    when 'GET'
      case info
        when nil            then                         :index
        when 'new'          then @info.shift;            :new
        when /(.);edit$/    then info.replace($`+$1);    :edit
        else REST.include?(info) || !respond_to?(info) ? :show : info
      end
    when 'POST'
      case info
        when nil            then                         :create
        when /(.);update$/  then info.replace($`+$1);    :update
        when /(.);destroy$/ then info.replace($`+$1);    :destroy
        else :create #!# raise "no nested resources"
      end
    when 'PUT'              then                         :update  if info
    when 'DELETE'           then                         :destroy if info
  end

  # perform the action or eject
  if @action && respond_to?(@action)
    @follow = THEN[@action]
    send @action
  else
    eject
  end

  # determine how to follow the action (render or redirect)
  case http
  when 'GET'
    send @follow if @follow
  when 'POST', 'PUT', 'DELETE'
    case @follow
      when nil
      when :index then redirect_to('', 303)
      when :edit  then redirect_to("#{@id};edit", 303)
      when :show  then redirect_to(@id, 303)
      else respond_to?(@follow) ? send(@follow) : eject
    end
  end
end