def handle(self, request):
"""
Handle a request by dispatching it off to the correct handler.
The handler is a 'browser' class, which can be looked up via the
BROWSER_MAP that is defined in the settings file.
This also catches any RestxExceptions thrown by lower level code and
translates them into log messages.
@param request: A properly wrapped request.
@type request: RestxHttpRequest
@return: Response structure and headers
@rtype: Tuple of (Result, dict)
"""
content_type = None
try:
if request.getRequestPath() == "/":
browser_class = BROWSER_MAP['/meta']
else:
method = request.getRequestMethod().upper()
prefix = "/" + request.getRequestPath().split("/")[1]
browser_class = BROWSER_MAP.get(prefix)
if browser_class:
browser_instance = browser_class(request)
result = browser_instance.process()
if result.getStatus() >= 200 and result.getStatus() < 300:
headers = result.getHeaders()
# Check if the Content-type return header was set by
# the component. If so, we assume that the component
# has returned data in the appropriate format already
# and we will not perform any encoding.
# For example, if an image file is returned then the
# component may have set the content type to "image/jpg".
if headers:
content_type = result.getHeaders().get("Content-type")
else:
content_type = None
if content_type is None:
# If all was OK with the request then we will
# render the output in the format that was
# requested by the client. But only if we don't
# have a content-type set on this request already.
content_type, data = browser_instance.renderOutput(
result.getEntity())
result.setEntity(data)
else:
result = Result.notFound("Not found")
except RestxMethodNotAllowedException, e:
result = Result(e.code, e.msg)
def process(self):
"""
Process the request.
@return: HTTP result structure.
@rtype: Result
"""
method = self.request.getRequestMethod()
if method == HTTP.GET_METHOD:
# It's the responsibility of the browser class to provide breadcrumbs
self.breadcrumbs = [("Home", "/"),
("Resource", settings.PREFIX_RESOURCE)]
if self.request.getRequestPath() == settings.PREFIX_RESOURCE:
#
# Request to the base URL of all resources (listing resources)
#
if method == HTTP.GET_METHOD:
#
# List all the resources
#
return Result.ok(listResources())
else:
raise RestxMethodNotAllowedException()
else:
# Path elements (the known resource prefix is stripped off)
path = self.request.getRequestPath()[len(settings.PREFIX_RESOURCE
):]
path_elems = path.split("/")[1:]
resource_name = path_elems[
0] # This should be the name of the resource base
# If the path ends with a '/' then there might be an empty element at the end,
# which we can remove.
if not path_elems[-1:][0]:
path_elems.pop()
# Before calling delete on a resource, we have to make sure that this DELETE
# is just for the resource itself, not a DELETE to some of the sub-services.
# If it's just for the resource then there will be only one path element (the
# resource name).
if method == HTTP.DELETE_METHOD and len(path_elems) == 1:
try:
deleteResourceFromStorage(self.request.getRequestPath())
return Result.ok("Resource deleted")
except RestxException, e:
return Result(e.code, str(e))
# Get the public representation of the resource
rinfo = _getResourceDetails(resource_name)
complete_resource_def = rinfo['complete_resource_def']
resource_home_uri = rinfo['resource_home_uri']
public_resource_def = rinfo['public_resource_def']
code_uri = rinfo['code_uri']
component = rinfo['component']
services = public_resource_def['services']
public_resource_def['uri'] = Url(public_resource_def['uri'])
if method == HTTP.GET_METHOD:
self.breadcrumbs.append((resource_name, resource_home_uri))
# Was there more to access?
if len(path_elems) > 1:
#
# Some sub-service of the component was requested. This means
# we actually need to pass the parameters to the component
# and call this service function.
#
# This service has some possible runtime parameters defined.
runtime_param_dict = get_request_query_dict(self.request)
service_name = path_elems[1]
positional_params = path_elems[2:]
input = self.request.getRequestBody()
try:
http_method = __HTTP_METHOD_LOOKUP.get(
self.request.getRequestMethod().upper(),
HttpMethod.UNKNOWN)
result = _accessComponentService(
component, services, complete_resource_def,
resource_name, service_name, positional_params,
runtime_param_dict, input, self.request, http_method)
except RestxException, e:
result = Result(e.code, e.msg)
except Exception, e:
# The service code threw an exception. We need to log that and return a
# normal error back to the user.
print traceback.format_exc()
log("Exception in component for service '%s': %s" %
(service_name, str(e)),
facility=LOGF_COMPONENTS)
result = Result.internalServerError(
"Internal server error. Details have been logged...")
# and we will not perform any encoding.
# For example, if an image file is returned then the
# component may have set the content type to "image/jpg".
if headers:
content_type = result.getHeaders().get("Content-type")
else:
content_type = None
if content_type is None:
# If all was OK with the request then we will
# render the output in the format that was
# requested by the client. But only if we don't
# have a content-type set on this request already.
content_type, data = browser_instance.renderOutput(
result.getEntity())
result.setEntity(data)
else:
result = Result.notFound("Not found")
except RestxMethodNotAllowedException, e:
result = Result(e.code, e.msg)
except RestxMandatoryParameterMissingException, e:
result = Result(e.code, e.msg)
except RestxFileNotFoundException, e:
result = Result(e.code, e.msg)
except RestxException, e:
result = Result.badRequest("Bad request: " + e.msg)
if content_type:
result.addHeader("Content-type", content_type)
return result
