helpers.rb

module Sinatra
  module UserHelper

    # This incredibly useful helper gives us the currently logged in user. We
    # keep track of that by just setting a session variable with their id. If it
    # doesn't exist, we just want to return nil.
    def current_user
      return unless session[:user_id]
      @current_user ||= User.first(:id => session[:user_id])
    end

    # This very simple method checks if we've got a logged in user. That's pretty
    # easy: just check our current_user.
    def logged_in?
      current_user
    end

    # Our `admin_only!` helper will only let admin users visit the page. If
    # they're not an admin, we redirect them to either / or the page that we
    # specified when we called it.
    def admin_only!(opts = {:return => "/"})
      unless logged_in? && current_user.admin?
        flash[:error] = "Sorry, buddy"
        redirect opts[:return]
      end
    end

    # Similar to `admin_only!`, `require_login!` only lets logged in users access
    # a particular page, and redirects them if they're not.
    def require_login!(opts = {:return => "/"})
      unless logged_in?
        flash[:error] = "Sorry, buddy"
        redirect opts[:return]
      end
    end

    def set_params_page
      params[:page] ||= 1
      params[:per_page] ||= 25
      params[:page] = params[:page].to_i
      params[:per_page] = params[:per_page].to_i
    end

    def set_next_prev_page
      @next_page = "?#{Rack::Utils.build_query :page => params[:page] + 1}"

      if params[:page] > 1
        @prev_page = "?#{Rack::Utils.build_query :page => params[:page] - 1}"
      else
        @prev_page = nil
      end
    end
  end

  helpers UserHelper
end