module ActionController
module Scaffolding # :nodoc:
def self.append_features(base)
super
base.extend(ClassMethods)
end
# Scaffolding is a way to quickly put an Active Record class online by providing a series of standardized actions
# for listing, showing, creating, updating, and destroying objects of the class. These standardized actions come
# with both controller logic and default templates that through introspection already know which fields to display
# and which input types to use. Example:
#
# class WeblogController < ActionController::Base
# scaffold :entry
# end
#
# This tiny piece of code will add all of the following methods to the controller:
#
# class WeblogController < ActionController::Base
# def index
# list
# end
#
# def list
# @entries = Entry.find_all
# render_scaffold "list"
# end
#
# def show
# @entry = Entry.find(params[:id])
# render_scaffold
# end
#
# def destroy
# Entry.find(params[:id]).destroy
# redirect_to :action => "list"
# end
#
# def new
# @entry = Entry.new
# render_scaffold
# end
#
# def create
# @entry = Entry.new(params[:entry])
# if @entry.save
# flash[:notice] = "Entry was successfully created"
# redirect_to :action => "list"
# else
# render_scaffold('new')
# end
# end
#
# def edit
# @entry = Entry.find(params[:id])
# render_scaffold
# end
#
# def update
# @entry = Entry.find(params[:id])
# @entry.attributes = params[:entry]
#
# if @entry.save
# flash[:notice] = "Entry was successfully updated"
# redirect_to :action => "show", :id => @entry
# else
# render_scaffold('edit')
# end
# end
# end
#
# The <tt>render_scaffold</tt> method will first check to see if you've made your own template (like "weblog/show.rhtml" for
# the show action) and if not, then render the generic template for that action. This gives you the possibility of using the
# scaffold while you're building your specific application. Start out with a totally generic setup, then replace one template
# and one action at a time while relying on the rest of the scaffolded templates and actions.
module ClassMethods
# Adds a swath of generic CRUD actions to the controller. The +model_id+ is automatically converted into a class name unless
# one is specifically provide through <tt>options[:class_name]</tt>. So <tt>scaffold :post</tt> would use Post as the class
# and @post/@posts for the instance variables.
#
# It's possible to use more than one scaffold in a single controller by specifying <tt>options[:suffix] = true</tt>. This will
# make <tt>scaffold :post, :suffix => true</tt> use method names like list_post, show_post, and create_post
# instead of just list, show, and post. If suffix is used, then no index method is added.
def scaffold(model_id, options = {})
validate_options([ :class_name, :suffix ], options.keys)
singular_name = model_id.to_s
class_name = options[:class_name] || singular_name.camelize
plural_name = singular_name.pluralize
suffix = options[:suffix] ? "_#{singular_name}" : ""
unless options[:suffix]
module_eval <<-"end_eval", __FILE__, __LINE__
def index
list
end
end_eval
end
module_eval <<-"end_eval", __FILE__, __LINE__
def list#{suffix}
@#{singular_name}_pages, @#{plural_name} = paginate :#{plural_name}, :per_page => 10
render#{suffix}_scaffold "list#{suffix}"
end
def show#{suffix}
@#{singular_name} = #{class_name}.find(params[:id])
render#{suffix}_scaffold
end
def destroy#{suffix}
#{class_name}.find(params[:id]).destroy
redirect_to :action => "list#{suffix}"
end
def new#{suffix}
@#{singular_name} = #{class_name}.new
render#{suffix}_scaffold
end
def create#{suffix}
@#{singular_name} = #{class_name}.new(params[:#{singular_name}])
if @#{singular_name}.save
flash[:notice] = "#{class_name} was successfully created"
redirect_to :action => "list#{suffix}"
else
render#{suffix}_scaffold('new')
end
end
def edit#{suffix}
@#{singular_name} = #{class_name}.find(params[:id])
render#{suffix}_scaffold
end
def update#{suffix}
@#{singular_name} = #{class_name}.find(params[:id])
@#{singular_name}.attributes = params[:#{singular_name}]
if @#{singular_name}.save
flash[:notice] = "#{class_name} was successfully updated"
redirect_to :action => "show#{suffix}", :id => @#{singular_name}
else
render#{suffix}_scaffold('edit')
end
end
private
def render#{suffix}_scaffold(action = caller_method_name(caller))
if template_exists?("\#{self.class.controller_path}/\#{action}")
render(:action => action)
else
@scaffold_class = #{class_name}
@scaffold_singular_name, @scaffold_plural_name = "#{singular_name}", "#{plural_name}"
@scaffold_suffix = "#{suffix}"
add_instance_variables_to_assigns
@content_for_layout = @template.render_file(scaffold_path(action.sub(/#{suffix}$/, "")), false)
if !active_layout.nil?
render :file => active_layout, :use_full_path => true
else
render :file => scaffold_path("layout")
end
end
end
def scaffold_path(template_name)
File.dirname(__FILE__) + "/templates/scaffolds/" + template_name + ".rhtml"
end
def caller_method_name(caller)
caller.first.scan(/`(.*)'/).first.first # ' ruby-mode
end
end_eval
end
private
# Raises an exception if an invalid option has been specified to prevent misspellings from slipping through
def validate_options(valid_option_keys, supplied_option_keys)
unknown_option_keys = supplied_option_keys - valid_option_keys
raise(ActionController::ActionControllerError, "Unknown options: #{unknown_option_keys}") unless unknown_option_keys.empty?
end
end
end
end
