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Improve request error handling
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@zimeon
zimeon committed May 16, 2016
1 parent 2365ec2 commit 7116d11
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Showing 3 changed files with 132 additions and 72 deletions.
147 changes: 93 additions & 54 deletions iiif/request.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,16 @@
from iiif.error import IIIFError, IIIFZeroSizeError


class IIIFRequestError(IIIFError):
"""Subclass of IIIFError for request parsing errors."""

def __init__(self, code=400, parameter='unknown',
text='request parsing error'):
"""Initialize."""
super(IIIFRequestError, self).__init__(
code=code, parameter=parameter, text=text)


class IIIFRequestBaseURI(Exception):
"""Subclass of Exception to indicate request for base URI."""

Expand Down Expand Up @@ -119,7 +129,8 @@ def quote(self, path_segment):
to-encode = "%" / "/" / "?" / "#" / "[" / "]" / "@"
"""
return(urlquote(path_segment, "-._~!$&'()*+,;=:")) # FIXME - quotes too much
# FIXME - quotes too much
return(urlquote(path_segment, "-._~!$&'()*+,;=:"))

def url(self, **params):
"""Build a URL path for image or info request.
Expand Down Expand Up @@ -175,7 +186,7 @@ def parse_url(self, url):
Will parse a URL or URL path that accords with either the
parametrized or info request forms. Will raise an
IIIFError on failure. A wrapper for the split_url()
IIIFRequestError on failure. A wrapper for the split_url()
and parse_parameters() methods.
Note that behavior of split_url() depends on whether
Expand All @@ -187,10 +198,10 @@ def parse_url(self, url):
return(self)

def split_url(self, url):
"""Perform the initial parsing of an IIIF API URL path into components.
"""Parse an IIIF API URL path into components.
Will parse a URL or URL path that accords with either the
parametrized or info API forms. Will raise an IIIFError on
parametrized or info API forms. Will raise an IIIFRequestError on
failure.
If self.identifier is set then url is assumed not to include the
Expand All @@ -203,14 +214,14 @@ def split_url(self, url):
if (self.baseurl):
(path, num) = re.subn('^' + self.baseurl, '', url, 1)
if (num != 1):
raise IIIFError
raise IIIFRequestError()
url = path
# Break up by path segments, count to decide format
segs = url.split('/', 5)
if (identifier is not None):
segs.insert(0, identifier)
if (len(segs) > 5):
raise IIIFError
raise IIIFRequestError()
elif (len(segs) == 5):
self.identifier = urlunquote(segs[0])
self.region = urlunquote(segs[1])
Expand All @@ -222,18 +233,18 @@ def split_url(self, url):
self.identifier = urlunquote(segs[0])
info_name = self.strip_format(urlunquote(segs[1]))
if (info_name != "info"):
raise IIIFError
raise IIIFRequestError()
if (self.api_version == '1.0'):
if (self.format not in ['json', 'xml']):
raise IIIFError
raise IIIFRequestError()
elif (self.format != 'json'):
raise IIIFError
raise IIIFRequestError()
self.info = True
elif (len(segs) == 1):
self.identifier = urlunquote(segs[0])
raise IIIFRequestBaseURI
raise IIIFRequestBaseURI()
else:
raise IIIFError
raise IIIFRequestError()
return(self)

def strip_format(self, str_and_format):
Expand All @@ -255,9 +266,10 @@ def strip_format(self, str_and_format):
def parse_parameters(self):
"""Parse the parameters of an Image Information request.
Will throw an IIIFError on failure, set attributes on success. Care
is taken not to change any of the artibutes which store path
components. All parsed values are stored in new attributes.
Will throw an IIIFRequestError on failure, set attributes on
success. Care is taken not to change any of the artibutes
which store path components. All parsed values are stored
in new attributes.
"""
self.parse_region()
self.parse_size()
Expand Down Expand Up @@ -294,8 +306,11 @@ def parse_region(self):
# Now whether this was pct: or now, we expect 4 values...
str_values = xywh.split(',', 5)
if (len(str_values) != 4):
raise IIIFError(code=400, parameter="region",
text="Bad number of values in region specification, must be x,y,w,h but got %d value(s) from '%s'" % (len(str_values), xywh))
raise IIIFRequestError(
code=400, parameter="region",
text="Bad number of values in region specification, "
"must be x,y,w,h but got %d value(s) from '%s'" %
(len(str_values), xywh))
values = []
for str_value in str_values:
# Must be either integer (not pct) or interger/float (pct)
Expand All @@ -304,25 +319,33 @@ def parse_region(self):
# This is rather more permissive that the iiif spec
value = float(str_value)
except ValueError:
raise IIIFError(code=400, parameter="region",
text="Bad floating point value for percentage in region (%s)." % str_value)
raise IIIFRequestError(
code=400, parameter="region",
text="Bad floating point value for percentage in "
"region (%s)." % str_value)
if (value > 100.0):
raise IIIFError(code=400, parameter="region",
text="Percentage over value over 100.0 in region (%s)." % str_value)
raise IIIFRequestError(
code=400, parameter="region",
text="Percentage over value over 100.0 in region "
"(%s)." % str_value)
else:
try:
value = int(str_value)
except ValueError:
raise IIIFError(code=400, parameter="region",
text="Bad integer value in region (%s)." % str_value)
raise IIIFRequestError(
code=400, parameter="region",
text="Bad integer value in region (%s)." % str_value)
if (value < 0):
raise IIIFError(code=400, parameter="region",
text="Negative values not allowed in region (%s)." % str_value)
raise IIIFRequestError(
code=400, parameter="region",
text="Negative values not allowed in region (%s)." %
str_value)
values.append(value)
# Zero size region is w or h are zero (careful that they may be float)
if (values[2] == 0.0 or values[3] == 0.0):
raise IIIFZeroSizeError(code=400, parameter="region",
text="Zero size region specified (%s))." % xywh)
raise IIIFZeroSizeError(
code=400, parameter="region",
text="Zero size region specified (%s))." % xywh)
self.region_xywh = values

def parse_size(self, size=None):
Expand Down Expand Up @@ -362,23 +385,29 @@ def parse_size(self, size=None):
try:
self.size_pct = float(pct_str)
except ValueError:
raise IIIFError(code=400, parameter="size",
text="Percentage size value must be a number, got '%s'." % (pct_str))
raise IIIFRequestError(
code=400, parameter="size",
text="Percentage size value must be a number, got "
"'%s'." % (pct_str))
# FIXME - current spec places no upper limit on size
# if (self.size_pct<0.0 or self.size_pct>100.0):
# raise IIIFError(code=400,parameter="size",
# raise IIIFRequestError(code=400,parameter="size",
# text="Illegal percentage size, must be 0 <= pct <= 100.")
if (self.size_pct < 0.0):
raise IIIFError(code=400, parameter="size",
text="Base size percentage, must be > 0.0, got %f." % (self.size_pct))
raise IIIFRequestError(
code=400, parameter="size",
text="Base size percentage, must be > 0.0, got %f." %
(self.size_pct))
else:
if (self.size[0] == '!'):
# Have "!w,h" form
size_no_bang = self.size[1:]
(mw, mh) = self._parse_w_comma_h(size_no_bang, 'size')
if (mw is None or mh is None):
raise IIIFError(code=400, parameter="size",
text="Illegal size requested: both w,h must be specified in !w,h requests.")
raise IIIFRequestError(
code=400, parameter="size",
text="Illegal size requested: both w,h must be "
"specified in !w,h requests.")
self.size_wh = (mw, mh)
self.size_bang = True
else:
Expand All @@ -388,8 +417,9 @@ def parse_size(self, size=None):
(w, h) = self.size_wh
if ((w is not None and w <= 0) or
(h is not None and h <= 0)):
raise IIIFZeroSizeError(code=400, parameter='size',
text="Size parameters request zero size result image.")
raise IIIFZeroSizeError(
code=400, parameter='size',
text="Size parameters request zero size result image.")

def _parse_w_comma_h(self, whstr, param):
"""Utility to parse "w,h" "w," or ",h" values.
Expand All @@ -402,18 +432,20 @@ def _parse_w_comma_h(self, whstr, param):
w = self._parse_non_negative_int(wstr, 'w')
h = self._parse_non_negative_int(hstr, 'h')
except ValueError as e:
raise IIIFError(code=400, parameter=param,
text="Illegal %s value (%s)." % (param, str(e)))
raise IIIFRequestError(
code=400, parameter=param,
text="Illegal %s value (%s)." % (param, str(e)))
if (w is None and h is None):
raise IIIFError(code=400, parameter=param,
text="Must specify at least one of w,h for %s." % (param))
raise IIIFRequestError(
code=400, parameter=param,
text="Must specify at least one of w,h for %s." % (param))
return(w, h)

def _parse_non_negative_int(self, istr, name):
"""Parse integer from string (istr).
The (name) parameter is used just for IIIFError message generation
to indicate what the error is in.
The (name) parameter is used just for IIIFRequestError message
generation to indicate what the error is in.
"""
if (istr == ''):
return(None)
Expand All @@ -428,11 +460,11 @@ def _parse_non_negative_int(self, istr, name):
def parse_rotation(self, rotation=None):
"""Check and interpret rotation.
Uses value of self.rotation as starting point unless rotation parameter
is specified in the call. Sets self.rotation_deg to a floating point
number 0 <= angle < 360. Includes translation of 360 to 0. If there is
a prefix bang (!) then self.rotation_mirror will be set True, otherwise
it will be False.
Uses value of self.rotation as starting point unless rotation
parameter is specified in the call. Sets self.rotation_deg to a
floating point number 0 <= angle < 360. Includes translation of
360 to 0. If there is a prefix bang (!) then self.rotation_mirror
will be set True, otherwise it will be False.
"""
if (rotation is not None):
self.rotation = rotation
Expand All @@ -448,26 +480,33 @@ def parse_rotation(self, rotation=None):
try:
self.rotation_deg = float(self.rotation)
except ValueError:
raise IIIFError(code=400, parameter="rotation",
text="Bad rotation value, must be a number, got '%s'." % (self.rotation))
raise IIIFRequestError(
code=400, parameter="rotation",
text="Bad rotation value, must be a number, got '%s'." %
(self.rotation))
if (self.rotation_deg < 0.0 or self.rotation_deg > 360.0):
raise IIIFError(code=400, parameter="rotation",
text="Illegal rotation value, must be 0 <= rotation <= 360, got %f." % (self.rotation_deg))
raise IIIFRequestError(
code=400, parameter="rotation",
text="Illegal rotation value, must be 0 <= rotation "
"<= 360, got %f." % (self.rotation_deg))
elif (self.rotation_deg == 360.0):
# The spec admits 360 as valid, but change to 0
self.rotation_deg = 0.0

def parse_quality(self):
"""Check quality paramater.
Sets self.quality_val based on simple substitution of 'native' for
default. Checks for the three valid values else throws and IIIFError.
Sets self.quality_val based on simple substitution of
'native' for default. Checks for the three valid values
else throws an IIIFRequestError.
"""
if (self.quality is None):
self.quality_val = self.default_quality
elif (self.quality not in self.allowed_qualities):
raise IIIFError(code=400, parameter="quality",
text="The quality parameter must be '%s', got '%s'." % ("', '".join(self.allowed_qualities), self.quality))
raise IIIFRequestError(
code=400, parameter="quality",
text="The quality parameter must be '%s', got '%s'." %
("', '".join(self.allowed_qualities), self.quality))
else:
self.quality_val = self.quality

Expand Down
32 changes: 17 additions & 15 deletions tests/test_request_2_0.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,7 @@ class TestAll(TestRequests):

def test01_parse_region(self):
"""Region."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.region = None
r.parse_region()
self.assertTrue(r.region_full)
Expand Down Expand Up @@ -119,7 +119,7 @@ def test01_parse_region(self):

def test02_parse_region_bad(self):
"""Bad regions."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.region = 'pct:0,0,50,1000'
self.assertRaises(IIIFError, r.parse_region)
r.region = 'pct:-10,0,50,100'
Expand All @@ -129,7 +129,7 @@ def test02_parse_region_bad(self):

def test03_parse_size(self):
"""Size."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.parse_size('pct:100')
self.assertEqual(r.size_pct, 100.0)
self.assertFalse(r.size_bang)
Expand All @@ -152,7 +152,7 @@ def test03_parse_size(self):

def test04_parse_size_bad(self):
"""Bad sizes."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
self.assertRaises(IIIFError, r.parse_size, ',0.0')
self.assertRaises(IIIFError, r.parse_size, '0.0,')
self.assertRaises(IIIFError, r.parse_size, '1.0,1.0')
Expand All @@ -162,7 +162,7 @@ def test04_parse_size_bad(self):

def test05_parse_rotation(self):
"""Rotation."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.parse_rotation('0')
self.assertEqual(r.rotation_mirror, False)
self.assertEqual(r.rotation_deg, 0.0)
Expand Down Expand Up @@ -190,7 +190,7 @@ def test05_parse_rotation(self):

def test06_parse_rotation_bad(self):
"""Bad rotation."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.rotation = '-1'
self.assertRaises(IIIFError, r.parse_rotation)
r.rotation = '-0.0000001'
Expand All @@ -206,7 +206,7 @@ def test06_parse_rotation_bad(self):

def test07_parse_quality(self):
"""Quality."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.quality = None
r.parse_quality()
self.assertEqual(r.quality_val, 'default')
Expand All @@ -222,7 +222,7 @@ def test07_parse_quality(self):

def test08_parse_quality_bad(self):
"""Bad quality."""
r = IIIFRequest()
r = IIIFRequest(api_version='2.0')
r.quality = 'does_not_exist'
self.assertRaises(IIIFError, r.parse_quality)
# bad ones
Expand Down Expand Up @@ -255,15 +255,17 @@ def test12_decode_except(self):
IIIFRequest(api_version='2.0').split_url,
("id1/all/270/!pct%3A75.23.jpg"))

def test22_parse_response_codes(self):
def test20_bad_response_codes(self):
"""Response codes."""
r = IIIFRequest()
for (path, code) in [("a/b/c", 400),
("a/b/full/full/0/default.jpg", 404)]:
for (path, code) in [("id/b", 400),
("id/b/c", 400),
("id/b/c/d", 400),
("id/full/full/0/default.jpg/extra", 400)]:
got_code = None
try:
IIIFRequest().split_url(path)
IIIFRequest(api_version='2.0').split_url(path)
except IIIFError as e:
got_code = e.code
self.assertEqual(got_code, code, "Bad code %d, expected %d, for path %s" % (
got_code, code, path))
self.assertEqual(got_code, code,
"Bad code %s, expected %d, for path %s" %
(str(got_code), code, path))

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