# -*- coding: utf-8 -*-
import linecache
from watson.framework import __version__
from watson.common.imports import get_qualified_name
[docs]class ApplicationError(Exception):
"""A general purpose application error.
ApplicationError exceptions are used to redirect the user to relevant
http status error pages.
Attributes:
status_code (int): The status code to be used in the response
"""
status_code = 500
[docs] def __init__(self, message, status_code=None):
if status_code:
self.status_code = status_code
super(ApplicationError, self).__init__(message)
[docs]class NotFoundError(ApplicationError):
"""404 Not Found exception.
"""
status_code = 404
[docs]class InternalServerError(ApplicationError):
"""500 Internal Server Error exception.
"""
status_code = 500
[docs]class ExceptionHandler(object):
"""Processes an exception and formats a stack trace.
"""
[docs] def __init__(self, config=None):
self.config = config or {}
def __call__(self, exc_info):
code, message, cause_message, frames, type = self.__process_exception(
exc_info)
return {
'code': code,
'message': message,
'cause_message': cause_message,
'version': __version__,
'frames': frames,
'type': type,
'debug': self.config.get('enabled', True)
}
def __process_exception(self, exc_info):
try:
code = exc_info[1].status_code
except:
code = 500
exc = exc_info[1]
message = str(exc)
cause_message = None
try:
exc = exc.__cause__
tb = exc.__traceback__
cause_message = str(exc)
type = get_qualified_name(exc)
except:
tb = exc_info[2]
type = get_qualified_name(exc_info[0])
frames = []
while tb is not None:
frame = tb.tb_frame
line = tb.tb_lineno
co = frame.f_code
file = co.co_filename
function = co.co_name
linecache.checkcache(file)
sourcecode = linecache.getline(file, line, frame.f_globals)
this_frame = {
'line': line,
'file': file,
'function': function,
'code': sourcecode.strip(),
'vars': {}
}
frame_vars = frame.f_locals.items()
for var_name, value in frame_vars:
val = None
try:
val = str(value)
except: # pragma: no cover
try:
val = repr(value) # pragma: no cover
except:
val = None
this_frame['vars'][var_name] = val
frames.append(this_frame)
tb = tb.tb_next
frames.reverse()
del tb
return code, message, cause_message, frames, type