users_controller.rb

class UsersController < ApplicationController
  requires_authentication [:index, :show]

  def index
    @users = User.order(:id)
    respond_to do |format|
      format.html
      format.csv { send_data @users.to_csv }
      format.xls # { send_data @users.to_csv(col_sep: "\t") }
    end
  end

  def show
    @user = User.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @user }
    end
  end

  def new
    @user = User.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @user }
    end
  end

  def edit
    @user = User.find(params[:id])
  end

  def create
    @user = User.new(params[:user])

    respond_to do |format|
      if @user.save
        UserMailer.registration_confirmation(@user).deliver
        format.html { redirect_to @user, notice: 'User was successfully created.' }
        format.json { render json: @user, status: :created, location: @user }
      else
        format.html { render action: "new" }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  def update
    @user = User.find(params[:id])

    respond_to do |format|
      if @user.update_attributes(params[:user])
        format.html { redirect_to @user, notice: 'User was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  def destroy
    @user = User.find(params[:id])
    @user.destroy

    respond_to do |format|
      format.html { redirect_to users_url }
      format.json { head :no_content }
    end
  end
end