example_material_permission_handler.rb

class MaterialPermissionHandler < ApplicationPermissionHandler
  CODE_NAMES = [
    :show, :update, :delete, :edit
  ]
  def has_perm? user, code_name, object_id
    obj = Material.find_by_id object_id

    # Accept author.
    return true if user == obj.user
    case code_name
    when :show
      return true if obj and obj.scope == Material::SCOPE_PUBLIC
      return true if obj.scope == Material::SCOPE_GROUP and ProjectMember.where(project_id: obj.project_id, user_id: user.id).first
    when :edit, :update, :delete
      # Reject guest
      return false if user.nil?
      # Accept project member if public or group
      if obj and (obj.scope == Material::SCOPE_PUBLIC or obj.scope == Material::SCOPE_GROUP)
        return true if obj and ProjectMember.where(project_id: obj.project_id, user_id: user.id).first
      end
    end
    false
  end
end