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 render_scaffold 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 options[:class_name]. So scaffold :post 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 options[:suffix] = true. This will # make scaffold :post, :suffix => true 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