canvas-lms/lib/scope_filter.rb

58 lines
1.6 KiB
Ruby

# frozen_string_literal: true
#
# Copyright (C) 2015 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
class ScopeFilter
def initialize(context, user, relation=nil)
@context = context
@user = user
@relation = relation
end
attr_reader :context, :user
# Implement in subclasses.
def scope
@relation
end
private
def can?(*permissions)
permissions.all? do |permission|
context.grants_right?(user, permission)
end
end
# Facilitates conditionally chaining scopes.
# Use within subclassed implementations of #scope.
# i.e.:
#
# def scope
# concat_scope { context.active_assignments }
# concat_scope { @relation.published unless can_view_unpublished_assignments? }
# concat_scope do
# if context.feature_enabled?(:differentiated_assignments)
# DifferentiableAssignment.scope_filter(@relation, user, context)
# end
# end
# end
def concat_scope
@relation = yield || @relation
end
end