app/controllers/grades_controller.rb
class GradesController < ApplicationController
def create
current_user.grades.create(project_id: params[:project_id], stars: params[:stars])
redirect_to project_path(params[:project_id])
end
def destroy
@grade = current_user.grades.find(params[:id])
@grade.destroy
redirect_to project_path(params[:project_id])
end
end