def get_param_as_bool(self, name, required=False, store=None):
"""Return the value of a query string parameter as a boolean
The following bool-like strings are supported::
TRUE_STRINGS = ('true', 'True', 'yes')
FALSE_STRINGS = ('false', 'False', 'no')
Args:
name (str): Parameter name, case-sensitive (e.g., 'limit')
required (bool, optional): Set to True to raise HTTPBadRequest
instead of returning gracefully when the parameter is not
found or is not a recognized bool-ish string (default False).
store (dict, optional): A dict-like object in which to place the
value of the param, but only if the param is found (default
*None*).
Returns:
bool: The value of the param if it is found and can be converted
to a boolean. If the param is not found, returns *None* unless
required is True.
Raises
HTTPBadRequest: The param was not found in the request, even though
it was required to be there.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
if val in TRUE_STRINGS:
val = True
elif val in FALSE_STRINGS:
val = False
else:
msg = 'The value of the parameter must be "true" or "false".'
raise InvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return None
description = 'The "' + name + '" query parameter is required.'
raise HTTPBadRequest('Missing query parameter', description)
def get_param_as_list(self,
name,
transform=None,
required=False,
store=None):
"""Return the value of a query string parameter as a list.
Note that list items must be comma-separated.
Args:
name (str): Parameter name, case-sensitive (e.g., 'limit')
transform (callable, optional): An optional transform function
that takes as input each element in the list as a string and
outputs a transformed element for inclusion in the list that
will be returned. For example, passing the int function will
transform list items into numbers.
required (bool, optional): Set to True to raise HTTPBadRequest
instead of returning gracefully when the parameter is not
found or is not an integer (default False)
store (dict, optional): A dict-like object in which to place the
value of the param, but only if the param is found (default
*None*).
Returns:
list: The value of the param if it is found. Otherwise, returns
*None* unless required is True. for partial lists, *None* will be
returned as a placeholder. For example::
things=1,,3
would be returned as::
['1', None, '3']
while this::
things=,,,
would just be retured as::
[None, None, None, None]
Raises
HTTPBadRequest: The param was not found in the request, but was
required.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
items = params[name].split(',')
# PERF(kgriffs): Use if-else rather than a DRY approach
# that sets transform to a passthrough function; avoids
# function calling overhead.
if transform is None:
items = [i if i != '' else None for i in items]
else:
try:
items = [transform(i) if i != '' else None for i in items]
except ValueError:
msg = 'The value is not formatted correctly.'
raise InvalidParam(msg, name)
if store is not None:
store[name] = items
return items
if not required:
return None
raise HTTPBadRequest('Missing query parameter',
'The "' + name + '" query parameter is required.')
def get_param_as_int(self,
name,
required=False,
min=None,
max=None,
store=None):
"""Return the value of a query string parameter as an int.
Args:
name (str): Parameter name, case-sensitive (e.g., 'limit')
required (bool, optional): Set to True to raise HTTPBadRequest
instead of returning gracefully when the parameter is not
found or is not an integer (default False).
min (int, optional): Set to the minimum value allowed for this
param. If the param is found and it is less than min, an
HTTPError is raised.
max (int, optional): Set to the maximum value allowed for this
param. If the param is found and its value is greater than
max, an HTTPError is raised.
store (dict, optional): A dict-like object in which to place the
value of the param, but only if the param is found (default
*None*).
Returns:
int: The value of the param if it is found and can be converted to
an integer. If the param is not found, returns *None*, unless
``required`` is True.
Raises
HTTPBadRequest: The param was not found in the request, even though
it was required to be there. Also raised if the param's value
falls outside the given interval, i.e., the value must be in
the interval: min <= value <= max to avoid triggering an error.
"""
params = self._params
# PERF: Use if..in since it is a good all-around performer; we don't
# know how likely params are to be specified by clients.
if name in params:
val = params[name]
try:
val = int(val)
except ValueError:
msg = 'The value must be an integer.'
raise InvalidParam(msg, name)
if min is not None and val < min:
msg = 'The value must be at least ' + str(min)
raise InvalidParam(msg, name)
if max is not None and max < val:
msg = 'The value may not exceed ' + str(max)
raise InvalidParam(msg, name)
if store is not None:
store[name] = val
return val
if not required:
return None
description = 'The "' + name + '" query parameter is required.'
raise HTTPBadRequest('Missing query parameter', description)