canvas-lms/lib/api.rb

629 lines
23 KiB
Ruby

#
# Copyright (C) 2011 - 2014 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
include Api::Errors::ControllerMethods
# 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, account: nil)
result = api_find_all(collection, [id], account: account).first
raise(ActiveRecord::RecordNotFound, "Couldn't find #{collection.name} with API id '#{id}'") unless result
result
end
def api_find_all(collection, ids, account: nil)
if collection.table_name == User.table_name && @current_user
ids = ids.map{|id| id == 'self' ? @current_user.id : id }
end
if collection.table_name == Account.table_name
ids = ids.map do |id|
case id
when 'self'
@domain_root_account.id
when 'default'
Account.default.id
when 'site_admin'
Account.site_admin.id
else
id
end
end
end
if collection.table_name == EnrollmentTerm.table_name
current_term = nil
ids = ids.map do |id|
case id
when 'default'
@domain_root_account.default_enrollment_term
when 'current'
if !current_term
current_terms = @domain_root_account
.enrollment_terms
.active
.where("(start_at<=? OR start_at IS NULL) AND (end_at >=? OR end_at IS NULL) AND NOT (start_at IS NULL AND end_at IS NULL)", Time.now.utc, Time.now.utc)
.limit(2)
.to_a
current_term = current_terms.length == 1 ? current_terms.first : :nil
end
current_term == :nil ? nil : current_term
else
id
end
end
end
Api.sis_relation_for_collection(collection, ids, account || @domain_root_account, @current_user)
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, current_user = nil)
sis_mapping = sis_find_sis_mapping_for_collection(collection)
columns = sis_parse_ids(ids, sis_mapping[:lookups], current_user)
result = columns.delete(sis_mapping[:lookups]["id"]) || []
unless columns.empty?
relation = relation_for_sis_mapping_and_columns(collection, columns, sis_mapping, root_account)
# pluck ignores eager_load
relation = relation.joins(*relation.eager_load_values) if relation.eager_load_values.present?
result.concat relation.pluck(:id)
result.uniq!
end
result
end
SIS_MAPPINGS = {
'courses' =>
{ :lookups => { 'sis_course_id' => 'sis_source_id',
'id' => 'id',
'sis_integration_id' => 'integration_id',
'lti_context_id' => 'lti_context_id' }.freeze,
:is_not_scoped_to_account => ['id'].freeze,
:scope => 'root_account_id' }.freeze,
'enrollment_terms' =>
{ :lookups => { 'sis_term_id' => 'sis_source_id',
'id' => 'id',
'sis_integration_id' => 'integration_id' }.freeze,
:is_not_scoped_to_account => ['id'].freeze,
:scope => 'root_account_id' }.freeze,
'users' =>
{ :lookups => { 'sis_user_id' => 'pseudonyms.sis_user_id',
'sis_login_id' => {
column: 'LOWER(pseudonyms.unique_id)',
transform: ->(id) { QuotedValue.new("LOWER(#{Pseudonym.connection.quote(id)})") }
},
'id' => 'users.id',
'sis_integration_id' => 'pseudonyms.integration_id',
'lti_context_id' => 'users.lti_context_id',
'lti_user_id' => 'users.lti_context_id' }.freeze,
:is_not_scoped_to_account => ['users.id', 'users.lti_context_id'].freeze,
:scope => 'pseudonyms.account_id',
:joins => :pseudonym }.freeze,
'accounts' =>
{ :lookups => { 'sis_account_id' => 'sis_source_id',
'id' => 'id',
'sis_integration_id' => 'integration_id',
'lti_context_id' => 'lti_context_id' }.freeze,
:is_not_scoped_to_account => ['id', 'lti_context_id'].freeze,
:scope => 'root_account_id' }.freeze,
'course_sections' =>
{ :lookups => { 'sis_section_id' => 'sis_source_id',
'id' => 'id',
'sis_integration_id' => 'integration_id' }.freeze,
:is_not_scoped_to_account => ['id'].freeze,
:scope => 'root_account_id' }.freeze,
'groups' =>
{ :lookups => { 'sis_group_id' => 'sis_source_id',
'id' => 'id' }.freeze,
:is_not_scoped_to_account => ['id'].freeze,
:scope => 'root_account_id' }.freeze,
}.freeze
# (digits in 2**63-1) - 1, so that any ID representable in MAX_ID_LENGTH
# digits is < 2**63, which is the max signed 64-bit integer, which is what's
# used for the DB ids.
MAX_ID_LENGTH = 18
ID_REGEX = %r{\A\d{1,#{MAX_ID_LENGTH}}\z}
def self.sis_parse_id(id, lookups, _current_user = nil)
# returns column_name, column_value
return lookups['id'], id if id.is_a?(Numeric) || id.is_a?(ActiveRecord::Base)
id = id.to_s.strip
if id =~ %r{\Ahex:(lti_[\w_]+|sis_[\w_]+):(([0-9A-Fa-f]{2})+)\z}
sis_column = $1
sis_id = [$2].pack('H*')
elsif id =~ %r{\A(lti_[\w_]+|sis_[\w_]+):(.+)\z}
sis_column = $1
sis_id = $2
elsif id =~ ID_REGEX
return lookups['id'], (id =~ /\A\d+\z/ ? id.to_i : id)
else
return nil, nil
end
column = lookups[sis_column]
return nil, nil unless column
if column.is_a?(Hash)
sis_id = column[:transform].call(sis_id)
column = column[:column]
end
return column, sis_id
end
def self.sis_parse_ids(ids, lookups, current_user = nil)
# returns {column_name => [column_value,...].uniq, ...}
columns = {}
ids.compact.each do |id|
column, sis_id = sis_parse_id(id, lookups, current_user)
next unless column && sis_id
columns[column] ||= []
columns[column] << sis_id
end
columns.keys.each { |key| columns[key].uniq! }
return columns
end
# remove things that don't look like valid database IDs
# return in integer format if possible
# (note that ID_REGEX may be redefined by a plugin!)
def self.map_non_sis_ids(ids)
ids.map{ |id| id.to_s.strip }.select{ |id| id =~ ID_REGEX }.map do |id|
id =~ /\A\d+\z/ ? id.to_i : id
end
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_relation_for_collection(collection, ids, sis_root_account, current_user = nil)
relation_for_sis_mapping(collection,
sis_find_sis_mapping_for_collection(collection),
ids,
sis_root_account,
current_user)
end
def self.relation_for_sis_mapping(relation, sis_mapping, ids, sis_root_account, current_user = nil)
relation_for_sis_mapping_and_columns(relation,
sis_parse_ids(ids, sis_mapping[:lookups], current_user),
sis_mapping,
sis_root_account)
end
def self.relation_for_sis_mapping_and_columns(relation, columns, sis_mapping, sis_root_account)
raise ArgumentError, "sis_root_account required for lookups" unless sis_root_account.is_a?(Account)
return relation.none if columns.empty?
not_scoped_to_account = sis_mapping[:is_not_scoped_to_account] || []
if columns.length == 1 && not_scoped_to_account.include?(columns.keys.first)
relation = relation.where(columns)
else
args = []
query = []
columns.keys.sort.each do |column|
if not_scoped_to_account.include?(column)
query << "#{column} IN (?)"
args << columns[column]
else
raise ArgumentError, "missing scope for collection" unless sis_mapping[:scope]
ids = columns[column]
if ids.any? { |id| id.is_a?(Array) }
ids_hash = {}
ids.each do |id|
id = Array(id)
account = id.last || sis_root_account
ids_hash[account] ||= []
ids_hash[account] << id.first
end
else
ids_hash = { sis_root_account => ids }
end
ids_hash.each do |root_account, ids|
query << "(#{sis_mapping[:scope]} = #{root_account.id} AND #{column} IN (?))"
args << ids
end
end
end
args.unshift(query.join(" OR "))
relation = relation.where(*args)
end
relation = relation.eager_load(sis_mapping[:joins]) if sis_mapping[:joins]
relation
end
def self.max_per_page
Setting.get('api_max_per_page', '50').to_i
end
def self.per_page
Setting.get('api_per_page', '10').to_i
end
def self.per_page_for(controller, options={})
per_page_requested = controller.params[:per_page] || options[:default] || per_page
max = options[:max] || max_per_page
[[per_page_requested.to_i, 1].max, max.to_i].min
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 = {}, response_args = {})
collection = paginate_collection!(collection, controller, pagination_args)
hash = build_links_hash(base_url, meta_for_pagination(controller, collection))
links = build_links_from_hash(hash)
controller.response.headers["Link"] = links.join(',') if links.length > 0
if response_args[:enhanced_return]
{hash: hash, collection: collection}
else
collection
end
end
# Returns collection as the first return value, and the meta information hash
# as the second return value
def self.jsonapi_paginate(collection, controller, base_url, pagination_args={})
collection = paginate_collection!(collection, controller, pagination_args)
meta = jsonapi_meta(collection, controller, base_url)
return collection, meta
end
def self.jsonapi_meta(collection, controller, base_url)
pagination = meta_for_pagination(controller, collection)
meta = {
per_page: collection.per_page
}
meta.merge!(build_links_hash(base_url, pagination))
if collection.ordinal_pages?
meta[:page] = pagination[:current]
meta[:template] = meta[:current].sub(/page=\d+/, "page={page}")
end
meta[:count] = collection.total_entries if collection.total_entries
meta[:page_count] = collection.total_pages if collection.total_pages
{ pagination: meta }
end
def self.paginate_collection!(collection, controller, pagination_args)
wrap_pagination_args!(pagination_args, controller)
begin
paginated = collection.paginate(pagination_args)
rescue Folio::InvalidPage
if pagination_args[:page].to_s =~ /\d+/ && pagination_args[:page].to_i > 0 && collection.build_page.ordinal_pages?
# for backwards compatibility we currently require returning [] for
# pages beyond the end of an ordinal collection, rather than a 404.
paginated = Folio::Ordinal::Page.create
paginated.current_page = pagination_args[:page].to_i
else
# we're not dealing with a simple out-of-bounds on an ordinal
# collection, let the exception propagate (and turn into a 404)
raise
end
end
paginated
end
def self.wrap_pagination_args!(pagination_args, controller)
pagination_args.reverse_merge!(
page: controller.params[:page],
per_page: per_page_for(controller,
default: pagination_args.delete(:default_per_page),
max: pagination_args.delete(:max_per_page)))
end
def self.meta_for_pagination(controller, collection)
{
query_parameters: controller.request.query_parameters,
per_page: collection.per_page,
current: collection.current_page,
next: collection.next_page,
prev: collection.previous_page,
first: collection.first_page,
last: collection.last_page,
}
end
PAGINATION_PARAMS = [:current, :next, :prev, :first, :last]
EXCLUDE_IN_PAGINATION_LINKS = %w(page per_page access_token api_key)
def self.build_links(base_url, opts={})
links = build_links_hash(base_url, opts)
build_links_from_hash(links)
end
def self.build_links_from_hash(links)
# iterate in order, but only using the keys present from build_links_hash
(PAGINATION_PARAMS & links.keys).map do |k|
v = links[k]
"<#{v}>; rel=\"#{k}\""
end
end
def self.build_links_hash(base_url, opts={})
base_url += (base_url =~ /\?/ ? '&': '?')
qp = opts[:query_parameters] || {}
qp = qp.with_indifferent_access.except(*EXCLUDE_IN_PAGINATION_LINKS)
base_url += "#{qp.to_query}&" if qp.present?
PAGINATION_PARAMS.each_with_object({}) do |param, obj|
if opts[param].present?
obj[param] = "#{base_url}page=#{opts[param]}&per_page=#{opts[:per_page]}"
end
end
end
def self.parse_pagination_links(link_header)
link_header.split(",").map do |link|
url, rel = link.match(%r{^<([^>]+)>; rel="([^"]+)"}).captures
uri = URI.parse(url)
raise(ArgumentError, "pagination url is not an absolute uri: #{url}") unless uri.is_a?(URI::HTTP)
Rack::Utils.parse_nested_query(uri.query).merge(:uri => uri, :rel => rel)
end
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.presence || media_object_or_hash.user_entered_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
def api_bulk_load_user_content_attachments(htmls, context = nil)
regex = context ? %r{/#{context.class.name.tableize}/#{context.id}/files/(\d+)} : %r{/files/(\d+)}
attachment_ids = []
htmls.compact.each do |html|
html.scan(regex).each do |match|
attachment_ids << match.first
end
end
if attachment_ids.blank?
{}
else
attachments = if context.is_a?(User) || context.nil?
Attachment.where(id: attachment_ids)
else
context.attachments.where(id: attachment_ids)
end
attachments.preload(:context).index_by(&:id)
end
end
PLACEHOLDER_PROTOCOL = 'https'
PLACEHOLDER_HOST = 'placeholder.invalid'
def get_host_and_protocol_from_request
[ request.host_with_port, request.ssl? ? 'https' : 'http' ]
end
def resolve_placeholders(content)
host, protocol = get_host_and_protocol_from_request
# content is a json-encoded string; slashes are escaped (at least in Rails 4.0)
content.gsub("#{PLACEHOLDER_PROTOCOL}:\\/\\/#{PLACEHOLDER_HOST}", "#{protocol}:\\/\\/#{host}").
gsub("#{PLACEHOLDER_PROTOCOL}://#{PLACEHOLDER_HOST}", "#{protocol}://#{host}")
end
def user_can_download_attachment?(attachment, context, user)
# checking on the context first can improve performance when checking many attachments for admins
(context && context.grants_any_right?(user, :manage_files, :read_as_admin)) || attachment.grants_right?(user, nil, :download)
end
def api_user_content(html, context = @context, user = @current_user, preloaded_attachments = {}, is_public=false)
return html if html.blank?
# use the host of the request if available;
# use a placeholder host for pre-generated content, which we will replace with the request host when available;
# otherwise let HostUrl figure out what host is appropriate
if self.respond_to?(:request)
host, protocol = get_host_and_protocol_from_request
elsif self.respond_to?(:use_placeholder_host?) && use_placeholder_host?
host = PLACEHOLDER_HOST
protocol = PLACEHOLDER_PROTOCOL
else
host = HostUrl.context_host(context, @account_domain.try(:host))
protocol = HostUrl.protocol
end
rewriter = UserContent::HtmlRewriter.new(context, user)
rewriter.set_handler('files') do |match|
if match.obj_id
obj = preloaded_attachments[match.obj_id]
obj ||= if context.is_a?(User) || context.nil?
Attachment.where(id: match.obj_id).first
else
context.attachments.find_by_id(match.obj_id)
end
end
unless obj && !obj.deleted? && ((is_public && !obj.locked_for?(user)) || user_can_download_attachment?(obj, context, user))
if obj && obj.previewable_media? && (uri = URI.parse(match.url) rescue nil)
uri.query = (uri.query.to_s.split("&") + ["no_preview=1"]).join("&")
next uri.to_s
else
next
end
end
if ["Course", "Group", "Account", "User"].include?(obj.context_type)
opts = {:only_path => true}
opts.merge!(:verifier => obj.uuid) unless respond_to?(:in_app?, true) && in_app? && !is_public
if match.rest.start_with?("/preview")
url = self.send("#{obj.context_type.downcase}_file_preview_url", obj.context_id, obj.id, opts)
else
opts[:download] = '1'
opts[:wrap] = '1' if match.rest.include?('wrap=1')
url = self.send("#{obj.context_type.downcase}_file_download_url", obj.context_id, obj.id, opts)
end
else
opts = {:download => '1', :only_path => true}
opts.merge!(:verifier => obj.uuid) unless respond_to?(:in_app?, true) && in_app? && !is_public
url = file_download_url(obj.id, opts)
end
url
end
html = rewriter.translate_content(html)
url_helper = Html::UrlProxy.new(self, context, host, protocol)
account = Context.get_account(context) || @domain_root_account
include_mobile = respond_to?(:mobile_device?, true) && mobile_device?
Html::Content.rewrite_outgoing(html, account, url_helper, include_mobile: include_mobile)
end
# This removes the verifier parameters that are added to attachment links by api_user_content
# and adds context (e.g. /courses/:id/) if it is missing
# exception: it leaves user-context file links alone
def process_incoming_html_content(html)
Html::Content.process_incoming(html)
end
def value_to_boolean(value)
Canvas::Plugin.value_to_boolean(value)
end
# takes a comma separated string, an array, or nil and returns an array
def self.value_to_array(value)
value.is_a?(String) ? value.split(',') : (value || [])
end
def self.invalid_time_stamp_error(attribute, message)
Canvas::Errors.capture(
'invalid_date_time',
message: "invalid #{attribute}",
exception_message: message
)
end
# regex for valid iso8601 dates
ISO8601_REGEX = /^(?<year>[0-9]{4})-
(?<month>1[0-2]|0[1-9])-
(?<day>3[0-1]|0[1-9]|[1-2][0-9])T
(?<hour>2[0-3]|[0-1][0-9]):
(?<minute>[0-5][0-9]):
(?<second>60|[0-5][0-9])
(?<fraction>\.[0-9]+)?
(?<timezone>Z|[+-](?:2[0-3]|[0-1][0-9]):[0-5][0-9])?$/x
# regex for valid dates
DATE_REGEX = /^\d{4}[- \/.](0[1-9]|1[012])[- \/.](0[1-9]|[12][0-9]|3[01])$/
# regex for shard-aware ID
ID = '(?:\d+~)?\d+'
# maps a Canvas data type to an API-friendly type name
API_DATA_TYPE = { "Attachment" => "File",
"WikiPage" => "Page",
"DiscussionTopic" => "Discussion",
"Assignment" => "Assignment",
"Quizzes::Quiz" => "Quiz",
"ContextModuleSubHeader" => "SubHeader",
"ExternalUrl" => "ExternalUrl",
"ContextExternalTool" => "ExternalTool",
"ContextModule" => "Module",
"ContentTag" => "ModuleItem" }.freeze
# matches the other direction, case insensitively
def self.api_type_to_canvas_name(api_type)
unless @inverse_map
m = {}
API_DATA_TYPE.each do |k, v|
m[v.downcase] = k
end
@inverse_map = m
end
return nil unless api_type
@inverse_map[api_type.downcase]
end
def self.recursively_stringify_json_ids(value, opts = {})
case value
when Hash
stringify_json_ids(value, opts)
value.each_value { |v| recursively_stringify_json_ids(v, opts) if v.is_a?(Hash) || v.is_a?(Array) }
when Array
value.each { |v| recursively_stringify_json_ids(v, opts) if v.is_a?(Hash) || v.is_a?(Array) }
end
value
end
def self.stringify_json_ids(value, opts = {})
return unless value.is_a?(Hash)
value.keys.each do |key|
if key =~ /(^|_)id$/
# id, foo_id, etc.
value[key] = stringify_json_id(value[key], opts)
elsif key =~ /(^|_)ids$/ && value[key].is_a?(Array)
# ids, foo_ids, etc.
value[key].map!{ |id| stringify_json_id(id, opts) }
end
end
end
def self.stringify_json_id(id, opts = {})
if opts[:reverse]
id.is_a?(String) ? id.to_i : id
else
id.is_a?(Integer) ? id.to_s : id
end
end
def accepts_jsonapi?
!!(/application\/vnd\.api\+json/ =~ request.headers['Accept'].to_s)
end
# Return a template url that follows the root links key for the jsonapi.org
# standard.
#
def templated_url(method, *args)
format = /^\{.*\}$/
placeholder = "PLACEHOLDER"
placeholders = args.each_with_index.map do |arg, index|
arg =~ format ? "#{placeholder}#{index}" : arg
end
url = send(method, *placeholders)
args.each_with_index do |arg, index|
url.sub!("#{placeholder}#{index}", arg) if arg =~ format
end
url
end
end