canvas-lms/lib/lti/asset.rb

79 lines
2.6 KiB
Ruby

# frozen_string_literal: true
#
# Copyright (C) 2014 - 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/>.
module Lti
class Asset
def self.opaque_identifier_for(asset, context: nil)
return if asset.blank?
shard = asset.shard
shard.activate do
lti_context_id = context_id_for(asset, shard)
set_asset_context_id(asset, lti_context_id, context: context)
end
end
def self.set_asset_context_id(asset, lti_context_id, context: nil)
if asset.respond_to?('lti_context_id')
global_context_id = global_context_id_for(asset)
if asset.new_record?
asset.lti_context_id = global_context_id
elsif asset.lti_context_id?
lti_context_id = (old_id = old_id_for_user_in_context(asset, context)) ? old_id : asset.lti_context_id
else
GuardRail.activate(:primary) {asset.reload}
unless asset.lti_context_id
asset.lti_context_id = global_context_id
GuardRail.activate(:primary) {asset.save!}
end
lti_context_id = asset.lti_context_id
end
end
lti_context_id
end
def self.old_id_for_user_in_context(asset, context)
if asset.is_a?(User) && context
context.shard.activate do
if asset.association(:past_lti_ids).loaded?
asset.past_lti_ids.find do |id|
id.context_id == context.id && id.context_type == context.class_name
end&.user_lti_context_id
else
asset.past_lti_ids.where(context: context).pluck(:user_lti_context_id).first
end
end
end
end
def self.context_id_for(asset, shard = nil)
shard ||= asset.shard
str = asset.asset_string.to_s
raise "Empty value" if str.blank?
Canvas::Security.hmac_sha1(str, shard.settings[:encryption_key])
end
def self.global_context_id_for(asset)
str = asset.global_asset_string.to_s
raise "Empty value" if str.blank?
Canvas::Security.hmac_sha1(str, asset.shard.settings[:encryption_key])
end
end
end