def get_all_courses(rules_text=None):
"""Reads all course rewrite rule definitions from environment variable."""
# Normalize text definition.
if not rules_text:
rules_text = GCB_COURSES_CONFIG.value
rules_text = rules_text.replace(',', '\n')
# Use cached value if exists.
cached = ApplicationContext.ALL_COURSE_CONTEXTS_CACHE.get(rules_text)
if cached:
return cached
# Compute the list of contexts.
rules = rules_text.split('\n')
slugs = {}
namespaces = {}
all_contexts = []
for rule in rules:
rule = rule.strip()
if not rule or rule.startswith('#'):
continue
parts = rule.split(':')
# validate length
if len(parts) < 3:
raise Exception('Expected rule definition of the form '
' \'type:slug:folder[:ns]\', got %s: ' % rule)
# validate type
if parts[0] != SITE_TYPE_COURSE:
raise Exception('Expected \'%s\', found: \'%s\'.'
% (SITE_TYPE_COURSE, parts[0]))
site_type = parts[0]
# validate slug
slug = parts[1]
slug_parts = urlparse.urlparse(slug)
if slug != slug_parts[2]:
raise Exception(
'Bad rule: \'%s\'. '
'Course URL prefix \'%s\' must be a simple URL fragment.' % (
rule, slug))
if slug in slugs:
raise Exception(
'Bad rule: \'%s\'. '
'Course URL prefix \'%s\' is already defined.' % (rule, slug))
slugs[slug] = True
# validate folder name
if parts[2]:
folder = parts[2]
# pylint: disable-msg=g-long-lambda
create_fs = lambda unused_ns: LocalReadOnlyFileSystem(
logical_home_folder=folder)
else:
folder = '/'
# pylint: disable-msg=g-long-lambda
create_fs = lambda ns: DatastoreBackedFileSystem(
ns=ns,
logical_home_folder=appengine_config.BUNDLE_ROOT,
inherits_from=LocalReadOnlyFileSystem(logical_home_folder='/'),
inheritable_folders=GCB_INHERITABLE_FOLDER_NAMES)
# validate or derive namespace
namespace = appengine_config.DEFAULT_NAMESPACE_NAME
if len(parts) == 4:
namespace = parts[3]
else:
if folder and folder != '/':
namespace = '%s%s' % (GCB_BASE_COURSE_NAMESPACE,
folder.replace('/', '-'))
try:
namespace_manager.validate_namespace(namespace)
except Exception as e:
raise Exception(
'Error validating namespace "%s" in rule "%s"; %s.' % (
namespace, rule, e))
if namespace in namespaces:
raise Exception(
'Bad rule \'%s\'. '
'Namespace \'%s\' is already defined.' % (rule, namespace))
namespaces[namespace] = True
all_contexts.append(ApplicationContext(
site_type, slug, folder, namespace,
AbstractFileSystem(create_fs(namespace)),
raw=rule))
_validate_appcontext_list(all_contexts)
# Cache result to avoid re-parsing over and over.
ApplicationContext.ALL_COURSE_CONTEXTS_CACHE = {rules_text: all_contexts}
return all_contexts
