controller_with_validation.rb

# replaces the create method in controller:
def create
  @movie = Movie.new(params[:movie])
  if @movie.save
    flash[:notice] = "#{@movie.title} was successfully created."
    redirect_to movies_path
  else
    redirect_to new_movie_path # note, 'new' template can access @movie's field values!
  end
end

# replaces the update method in controller:
def update
  @movie = Movie.find params[:id]
  if @movie.update_attributes(params[:movie])
    flash[:notice] = "#{@movie.title} was successfully updated."
    redirect_to movie_path(@movie)
  else
    redirect_to edit_movie_path(@movie)
  end
end