from logging import getLogger
from rdflib import Graph
from rdflib.plugin import PluginException, plugins
from rdflib.serializer import Serializer
from negotiator import ContentNegotiator, ContentType, AcceptParameters
from .crud import HashLessCRUDer, JSON_TYPES
from oldman.core.vocabulary import HTTP_POST
from oldman.core.exception import OMResourceNotFoundException, OMNotAcceptableException
from oldman.core.exception import OMMethodNotAllowedException, OMBadRequestException, OMObjectNotFoundError
[docs]class HTTPController(object):
"""
HTTP.
TODO: check declared methods (only GET and HEAD are implicit).
"""
DEFAULT_CONFIG = {'allow_put_new_type_existing_resource': False,
'allow_put_remove_type_existing_resource': False,
'allow_put_new_resource': True
}
def __init__(self, user_mediator, config={}):
self._logger = getLogger(__name__)
self._user_mediator = user_mediator
# For operations except POST
self._cruder = HashLessCRUDer(user_mediator)
self._config = self.DEFAULT_CONFIG.copy()
self._config.update(config)
self._negotiator = None
self._init_content_negotiator()
def _init_content_negotiator(self):
#TODO: use config instead
default_content_type = "application/ld+json"
default_accept_params = AcceptParameters(ContentType(default_content_type))
# rdf types
rdf_types = set([plugin.name for plugin in plugins(kind=Serializer) if "/" in plugin.name])
#Blacklisted because mapped to TriX that requires a context-aware store
blacklisted_types = ["application/xml"]
#TODO: consider other types
accepted_types = list(rdf_types.difference(blacklisted_types)) + ["application/json"]
self._logger.debug("Accepted types: %s" % accepted_types)
acceptable_params = [default_accept_params] + [AcceptParameters(ContentType(ct)) for ct in accepted_types]
self._negotiator = ContentNegotiator(default_accept_params, acceptable_params)
[docs] def get(self, hashless_iri, accept_header="*/*", **kwargs):
"""
TODO: describe.
No support declaration required.
"""
self._logger.debug("Accept header: %s" % accept_header)
accepted_type = self._negotiator.negotiate(accept=accept_header)
if accepted_type is None:
raise OMNotAcceptableException()
content_type = str(accepted_type.content_type)
self._logger.debug("Selected content-type: %s" % content_type)
try:
return self._cruder.get(hashless_iri, content_type)
except OMObjectNotFoundError:
raise OMResourceNotFoundException()
[docs] def head(self, hashless_iri, **kwargs):
"""
TODO: describe.
No support declaration required.
"""
#TODO: consider a more efficient implementation
try:
self._cruder.get(hashless_iri, None)
except OMObjectNotFoundError:
raise OMResourceNotFoundException()
[docs] def post(self, hashless_iri, content_type=None, payload=None, **kwargs):
"""
TODO: categorize the resource to decide what to do.
Support declaration and implementation are required.
"""
if content_type is None:
raise OMBadRequestException("Content type is required.")
#if payload is None:
# raise BadRequestException("No payload given.")
# Must be its ID (we do not consider resources with hash IRIs)
session = self._user_mediator.create_session()
resource = session.get(iri=hashless_iri)
if resource is None:
raise OMResourceNotFoundException()
operation = resource.get_operation(HTTP_POST)
if operation is not None:
graph = Graph()
try:
if content_type in JSON_TYPES:
resource = session.first(hashless_iri=hashless_iri)
graph.parse(data=payload, format="json-ld", publicID=hashless_iri,
context=resource.context)
else:
graph.parse(data=payload, format=content_type, publicID=hashless_iri)
except PluginException:
raise OMNotAcceptableException()
#TODO: add arguments
result = operation(resource, graph=graph, content_type=content_type)
session.close()
return result
#TODO: When error code is 405, alternatives must be given.
raise OMMethodNotAllowedException()
[docs] def put(self, hashless_iri, content_type=None, payload=None, **kwargs):
"""
TODO: describe.
No support declaration required.
"""
if content_type is None:
raise OMBadRequestException("Content type is required.")
if payload is None:
raise OMBadRequestException("No payload given.")
return self._cruder.update(self, hashless_iri, payload, content_type,
allow_new_type=False, allow_type_removal=False,
allow_put_new_resource=True)
[docs] def delete(self, hashless_iri, **kwargs):
"""
TODO: describe.
No declaration required.
"""
self._cruder.delete(hashless_iri)
[docs] def options(self, hashless_iri, **kwargs):
""" TODO: implement it """
raise NotImplementedError("")
[docs] def patch(self, hashless_iri, content_type=None, payload=None, **kwargs):
""" TODO: implement it """
if content_type is None:
raise OMBadRequestException("Content type is required.")
if payload is None:
raise OMBadRequestException("No payload given.")
raise NotImplementedError("PATCH is not yet supported.")