def __init__(self, application, request, **kwargs):
super(BaseHandler, self).__init__(application, request, **kwargs)
self.header_service = HeaderService(headers=request.headers)
class BaseHandler(tornado.web.RequestHandler):
"""
The most general handler class. Should be sub-classed by all consecutive
handler classes.
"""
def __init__(self, application, request, **kwargs):
super(BaseHandler, self).__init__(application, request, **kwargs)
self.header_service = HeaderService(headers=request.headers)
def prepare(self):
"""
Called before EVERY request GET/POST/etc. Here, we are requiring
the correct headers to be set before continuing to the actual request method.
"""
super(BaseHandler, self).prepare()
self.require_headers()
def set_default_headers(self):
self.set_header("Access-Control-Allow-Origin", "*")
self.set_header("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE,OPTIONS")
self.set_header(
"Access-Control-Allow-Headers",
"Content-Type, Depth, User-Agent, X-File-Size, "
"X-Requested-With, X-Requested-By, If-Modified-Since, "
"X-File-Name, Cache-Control, X-Api-Key",
)
def options(self, *args, **kwargs):
"""
Returning back the list of supported HTTP methods
"""
self.set_status(200)
self.set_header("Access-Control-Allow-Origin", "*")
self.set_header("Access-Control-Allow-Methods", ", ".join([str(x) for x in self.SUPPORTED_METHODS]))
self.write("ok")
# noinspection PyUnusedLocal
def respond(self, payload, status_code=200, status_message="OK"):
"""
The general responder for ALL cases (success response, error response)
"""
if payload is None:
payload = {}
if type(payload) not in [dict, list]:
logging.error("payload is: {}".format(payload))
logging.error("payload is type: {}".format(type(payload)))
raise NoDictionaryException()
response = Response(result=payload).get_data()
self.set_status(status_code)
self.set_header(
"X-Calvin", "You know, Hobbes, some days even my lucky rocketship underpants don’t help. --Bill Watterson"
)
self.set_header("Content-Type", "application/json; charset=UTF-8")
self.write(response)
if status_code in [200, 201, 204, 300]:
self.finish()
def write_error(self, status_code, **kwargs):
"""
Called automatically when an error occurred. But can also be used to
respond back to caller with a manual error.
"""
message = "Something went seriously wrong! Maybe invalid resource? Ask your admin for advice!"
if "exc_info" in kwargs:
error = kwargs["exc_info"]
if error[0] == KeyError:
message = "KeyError: a necessary key was not found."
else:
message = str(error[1])
if "message" in kwargs:
message = kwargs["message"]
self.respond(
status_code=status_code,
status_message=message,
payload={"incident_time": get_current_time_formatted(), "message": message},
)
def require_accept_header(self):
"""
Enforce application/json as Accept
"""
self.require_headers()
if not self.header_service.has_valid_accept_type():
self.write_error(status_code=406, message="Accept is not application/json.")
self.finish()
def require_content_type(self):
"""
Enforce application/json as content-type
"""
self.require_headers()
if not self.header_service.has_valid_content_type():
self.write_error(status_code=406, message="Content-Type is not set to application/json.")
self.finish()
def matches_api_key(self, api_key):
"""
Authorize request by enforcing API key (X-API-Key)
"""
self.require_headers()
if self.header_service.get_key_from_header("X-Api-Key") != api_key:
self.write_error(status_code=401, message="Invalid API Key.")
self.finish()
def require_headers(self):
"""
Helper for checking the required header variables
"""
if self.header_service.headers is None:
self.write_error(status_code=400, message="No headers set.")
self.finish()
