ability.rb

class Ability
  include CanCan::Ability

  def initialize(user)
    # Define abilities for the passed in user here. For example:
    #
    # user ||= User.new # guest user (not logged in)
    # if user.admin?
    #   can :manage, :all
    # else
    #   can :read, :all
    # end
      
    user ||= User.new
      
    if user.role == 'admin'
      can :manage, :all
    else
      can :manage, Job
      cannot :destroy, Job
      can :manage, Client
      cannot :destroy, Client
    end
    # The first argument to `can` is the action you are giving the user
    # permission to do.
    # If you pass :manage it will apply to every action. Other common actions
    # here are :read, :create, :update and :destroy.
    #
    # The second argument is the resource the user can perform the action on.
    # If you pass :all it will apply to every resource. Otherwise pass a Ruby
    # class of the resource.
    #
    # The third argument is an optional hash of conditions to further filter the
    # objects.
    # For example, here the user can only update published articles.
    #
    #   can :update, Article, :published => true
    #
    # See the wiki for details:
    # https://github.com/bryanrite/cancancan/wiki/Defining-Abilities
  end
end

trash_controller.rb

class TrashController < ApplicationController
  authorize_resource :job
  authorize_resource :client

  def index
    @items = model.only_deleted.order(:deleted_at => :desc).paginate(:page => params[:page], :per_page => 15)
  end
  
  def show
    @item = item
  end

  def destroy
    if item.destroyed?
      item.really_destroy!
      redirect_to :back, notice: "#{model.to_s} deleted."
    end
  end
  
  def restore
    model.restore(item)
    redirect_to :back, notice: "#{model.to_s} restored."
  end
  
private
  
  def item
    model.with_deleted.find(params[:id])
  end
  
  def model
    params[:model].classify.constantize if accepted_models.include? params[:model].capitalize
  end
  
  def accepted_models
    ["Client", "Job"]
  end
end