canvas-lms/lib/api.rb

253 lines
9.8 KiB
Ruby

#
# Copyright (C) 2011 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 Api
# find id in collection, by either id or sis_*_id
# if the collection is over the users table, `self` is replaced by @current_user.id
def api_find(collection, id)
api_find_all(collection, [id], 1).first || raise(ActiveRecord::RecordNotFound, "Couldn't find #{collection.name} with API id '#{id}'")
end
def api_find_all(collection, ids, limit=nil)
if collection.table_name == User.table_name && @current_user
ids = ids.map{|id| id == 'self' ? @current_user.id : id }
end
find_params = Api.sis_find_params_for_collection(collection, ids, @domain_root_account)
return [] if find_params[:conditions] == ["?", false]
find_params[:limit] = limit unless limit.nil?
return collection.all(find_params)
end
# map a list of ids and/or sis ids to plain ids.
# sis ids that can't be found in the db won't appear in the result, however
# AR object ids aren't verified to exist in the db so they'll still be
# returned in the result.
def self.map_ids(ids, collection, root_account)
sis_mapping = sis_find_sis_mapping_for_collection(collection)
columns = sis_parse_ids(ids, sis_mapping[:lookups])
result = columns.delete(sis_mapping[:lookups]["id"]) || []
unless columns.empty?
find_params = sis_make_params_for_sis_mapping_and_columns(columns, sis_mapping, root_account)
find_params[:select] = :id
result.concat collection.all(find_params).map(&:id)
result.uniq!
end
result
end
SIS_MAPPINGS = {
'courses' =>
{ :lookups => { 'sis_course_id' => 'sis_source_id', 'id' => 'id' },
:is_not_scoped_to_account => ['id'].to_set,
:scope => 'root_account_id' },
'enrollment_terms' =>
{ :lookups => { 'sis_term_id' => 'sis_source_id', 'id' => 'id' },
:is_not_scoped_to_account => ['id'].to_set,
:scope => 'root_account_id' },
'users' =>
{ :lookups => { 'sis_user_id' => 'pseudonyms.sis_user_id', 'sis_login_id' => 'pseudonyms.unique_id', 'id' => 'users.id' },
:is_not_scoped_to_account => ['users.id'].to_set,
:scope => 'pseudonyms.account_id',
:joins => [:pseudonym] },
'accounts' =>
{ :lookups => { 'sis_account_id' => 'sis_source_id', 'id' => 'id' },
:is_not_scoped_to_account => ['id'].to_set,
:scope => 'root_account_id' },
'course_sections' =>
{ :lookups => { 'sis_section_id' => 'sis_source_id', 'id' => 'id' },
:is_not_scoped_to_account => ['id'].to_set,
:scope => 'root_account_id' },
}.freeze
def self.sis_parse_id(id, lookups)
# returns column_name, column_value
return lookups['id'], id if id.is_a?(Numeric)
id = id.to_s.strip
if id =~ %r{\Ahex:(sis_[\w_]+):(([0-9A-Fa-f]{2})+)\z}
sis_column = $1
sis_id = [$2].pack('H*')
elsif id =~ %r{\A(sis_[\w_]+):(.+)\z}
sis_column = $1
sis_id = $2
elsif id =~ %r{\A\d+\z}
return lookups['id'], id.to_i
else
return nil, nil
end
column = lookups[sis_column]
return nil, nil unless column
return column, sis_id
end
def self.sis_parse_ids(ids, lookups)
# returns {column_name => [column_value,...].uniq, ...}
columns = {}
ids.compact.each do |id|
column, sis_id = sis_parse_id(id, lookups)
next unless column && sis_id
columns[column] ||= []
columns[column] << sis_id
end
columns.keys.each { |key| columns[key].uniq! }
return columns
end
def self.sis_find_sis_mapping_for_collection(collection)
SIS_MAPPINGS[collection.table_name] or
raise(ArgumentError, "need to add support for table name: #{collection.table_name}")
end
def self.sis_find_params_for_collection(collection, ids, sis_root_account)
return sis_find_params_for_sis_mapping(sis_find_sis_mapping_for_collection(collection), ids, sis_root_account)
end
def self.sis_find_params_for_sis_mapping(sis_mapping, ids, sis_root_account)
return sis_make_params_for_sis_mapping_and_columns(sis_parse_ids(ids, sis_mapping[:lookups]), sis_mapping, sis_root_account)
end
def self.sis_make_params_for_sis_mapping_and_columns(columns, sis_mapping, sis_root_account)
raise ArgumentError, "sis_root_account required for lookups" unless sis_root_account.is_a?(Account)
args = [false]
query = ["?"]
columns.keys.sort.each do |column|
sis_ids = columns[column]
if (sis_mapping[:is_not_scoped_to_account] || []).include?(column)
query << " OR (#{column} IN ("
else
raise ArgumentError, "missing scope for collection" unless sis_mapping[:scope]
query << " OR (#{sis_mapping[:scope]} = #{sis_root_account.id} AND #{column} IN ("
end
query << sis_ids.map{"?"}.join(", ")
args.concat sis_ids
query << "))"
end
find_params = { :conditions => ([query.join] + args) }
find_params[:include] = sis_mapping[:joins] if sis_mapping[:joins]
return find_params
end
# Add [link HTTP Headers](http://www.w3.org/Protocols/9707-link-header.html) for pagination
# The collection needs to be a will_paginate collection (or act like one)
# a new, paginated collection will be returned
def self.paginate(collection, controller, base_url, pagination_args = {})
per_page = [(controller.params[:per_page] || Setting.get_cached('api_per_page', '10')).to_i, Setting.get_cached('api_max_per_page', '50').to_i].min
collection = collection.paginate({ :page => controller.params[:page], :per_page => per_page }.merge(pagination_args))
return unless collection.respond_to?(:next_page)
links = []
base_url += (base_url =~ /\?/ ? '&': '?')
template = "<%spage=%s&per_page=#{collection.per_page}>; rel=\"%s\""
if collection.next_page
links << template % [base_url, collection.next_page, "next"]
end
if collection.previous_page
links << template % [base_url, collection.previous_page, "prev"]
end
links << template % [base_url, 1, "first"]
if !pagination_args[:without_count] && collection.total_pages && collection.total_pages > 1
links << template % [base_url, collection.total_pages, "last"]
end
controller.response.headers["Link"] = links.join(',') if links.length > 0
collection
end
def media_comment_json(media_object_or_hash)
media_object_or_hash = OpenStruct.new(media_object_or_hash) if media_object_or_hash.is_a?(Hash)
{
'content-type' => "#{media_object_or_hash.media_type}/mp4",
'display_name' => media_object_or_hash.title,
'media_id' => media_object_or_hash.media_id,
'media_type' => media_object_or_hash.media_type,
'url' => user_media_download_url(:user_id => @current_user.id,
:entryId => media_object_or_hash.media_id,
:type => "mp4",
:redirect => "1")
}
end
# stream an array of objects as a json response, without building a string of
# the whole response in memory.
def stream_json_array(array, json_opts)
response.content_type ||= Mime::JSON
render :text => proc { |r, o|
o.write('[')
array.each_with_index { |v,i|
o.write(v.to_json(json_opts));
o.write(',') unless i == array.length - 1
}
o.write(']')
}
end
# See User.submissions_for_given_assignments and SubmissionsApiController#for_students
mattr_accessor :assignment_ids_for_students_api
def api_user_content(html, context = @context, user = @current_user)
return html if html.blank?
# if we're a controller, use the host of the request, otherwise let HostUrl
# figure out what host is appropriate
if self.is_a?(ApplicationController)
host = request.host_with_port
else
host = HostUrl.context_host(context, @account_domain.try(:host))
end
rewriter = UserContent::HtmlRewriter.new(context, user)
rewriter.set_handler('files') do |match|
obj = match.obj_class.find_by_id(match.obj_id)
next unless obj && rewriter.user_can_view_content?(obj)
file_download_url(obj.id, :verifier => obj.uuid, :download => '1', :host => host)
end
html = rewriter.translate_content(html)
return html if html.blank?
# translate media comments into html5 video tags
doc = Nokogiri::HTML::DocumentFragment.parse(html)
doc.css('a.instructure_inline_media_comment').each do |anchor|
media_id = anchor['id'].try(:gsub, /^media_comment_/, '')
next if media_id.blank?
if anchor['class'].try(:match, /\baudio_comment\b/)
node = Nokogiri::XML::Node.new('audio', doc)
node['data-media_comment_type'] = 'audio'
else
node = Nokogiri::XML::Node.new('video', doc)
thumbnail = media_object_thumbnail_url(media_id, :width => 550, :height => 448, :type => 3, :host => host)
node['poster'] = thumbnail
node['data-media_comment_type'] = 'video'
end
node['preload'] = 'none'
node['class'] = 'instructure_inline_media_comment'
node['data-media_comment_id'] = media_id
media_redirect = polymorphic_url([context, :media_download], :entryId => media_id, :type => 'mp4', :redirect => '1', :host => host)
node['controls'] = 'controls'
node['src'] = media_redirect
anchor.replace(node)
end
return doc.to_s
end
end