global_rest_controller.rb

class GlobalRESTController < ApplicationController

  def index
    @objects = model_class.all

    respond_to do |format|
      format.html 
      format.xml  { render :xml => @objects }
    end
  end

  def show
    @object = model_class.find(params[:id])

    respond_to do |format|
      format.html 
      format.xml  { render :xml => @object }
    end
  end

  def new
    @object = model_class.new

    respond_to do |format|
      format.html 
      format.xml  { render :xml => @object }
    end
  end

  def edit
    @object = model_class.find(params[:id])
  end

  def create
    @object = model_class.new(params[model_param_name])

    respond_to do |format|
      if @object.save
        flash[:notice] = "#{model_class_name} was successfully created."
        format.html { redirect_to(@object) }
        format.xml  { render :xml => @object, :status => :created, :location => @object }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @object.errors, :status => :unprocessable_entity }
      end
    end
  end

  def update
    @object = model_class.find(params[:id])

    respond_to do |format|
      if @object.update_attributes(params[model_param_name])
        flash[:notice] = "#{model_class_name} was successfully updated."
        format.html { redirect_to(@object) }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @object.errors, :status => :unprocessable_entity }
      end
    end
  end

  def destroy
    @object = model_class.find(params[:id])
    @object.destroy

    respond_to do |format|
      format.html { redirect_to eval("#{params[:controller].underscore}_path") }
      format.xml  { head :ok }
    end
  end

  private
  
  # Gives the model class name. You can use it in your views, like "Add #{model_class_name}".
  def model_class_name
    @model_class_name ||= params[:controller].singularize.camelize
  end
  helper_method :model_class_name

  # Returns the class of the model for CRUD operations.
  def model_class
    @model_class ||= model_class_name.constantize
  end
  
  # Returns the name of the model parameters hash in the POST parameters.
  def model_param_name
    @model_param_name ||= params[:controller].singularize.downcase
  end
  
end