class Aborter(object):
"""
When passed a dict of code -> exception items it can be used as
callable that raises exceptions. If the first argument to the
callable is an integer it will be looked up in the mapping, if it's
a WSGI application it will be raised in a proxy exception.
The rest of the arguments are forwarded to the exception constructor.
"""
def __init__(self, mapping=None, extra=None):
if mapping is None:
mapping = default_exceptions
self.mapping = dict(mapping)
if extra is not None:
self.mapping.update(extra)
def __call__(self, code, *args, **kwargs):
if not args and not kwargs and not isinstance(code, integer_types):
raise HTTPException(response=code)
if code not in self.mapping:
raise LookupError('no exception for %r' % code)
raise self.mapping[code](*args, **kwargs)
default_exceptions = {}
__all__ = ['HTTPException']
def _find_exceptions():
for name, obj in iteritems(globals()):
try:
is_http_exception = issubclass(obj, HTTPException)
except TypeError:
is_http_exception = False
if not is_http_exception or obj.code is None:
continue
__all__.append(obj.__name__)
old_obj = default_exceptions.get(obj.code, None)
if old_obj is not None and issubclass(obj, old_obj):
continue
default_exceptions[obj.code] = obj
_find_exceptions()
del _find_exceptions
class NotFound(HTTPException):
"""*404* `Not Found`
Raise if a resource does not exist and never existed.
"""
code = 404
description = (
'The requested URL was not found on the server. '
'If you entered the URL manually please check your spelling and '
'try again.'
)
# get_response最终返回了一个Response对象
def get_response(self, environ=None):
"""Get a response object. If one was passed to the exception
it's returned directly.
:param environ: the optional environ for the request. This
can be used to modify the response depending
on how the request looked like.
:return: a :class:`Response` object or a subclass thereof.
"""
if self.response is not None:
return self.response
if environ is not None:
environ = _get_environ(environ)
headers = self.get_headers(environ)
# get_body获取页面文本内容
return Response(self.get_body(environ), self.code, headers)
get_body()
def get_body(self, environ=None):
"""Get the HTML body."""
return text_type((
u'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n'
u'<title>%(code)s %(name)s</title>\n'
u'<h1>%(name)s</h1>\n'
u'%(description)s\n'
) % {
'code': self.code,
'name': escape(self.name),
# self.get_description获取异常的description信息
'description': self.get_description(environ)
})
