def _pre_search_validation(self, location, query, sort_by,
return_fields, max_features):
"""Perform validation on the parameters of the search query.
Parameters
----------
location : pydov.util.location.AbstractLocationFilter
Location filter limiting the features to retrieve.
query : owslib.fes.OgcExpression
OGC filter expression to use for searching. This can contain any
combination of filter elements defined in owslib.fes. The query
should use the fields provided in `get_fields()`. Note that not
all fields are currently supported as a search parameter.
sort_by : owslib.fes.SortBy, optional
List of properties to sort by.
return_fields : list<str> or tuple<str> or set<str>
A list of fields to be returned in the output data. This should
be a subset of the fields provided in `get_fields()`.
max_features : int
Limit the maximum number of features to request.
Raises
------
pydov.util.errors.InvalidSearchParameterError
When not one of `location`, `query` or `max_features` is provided.
pydov.util.errors.InvalidFieldError
When at least one of the fields in `return_fields` is unknown.
When a field that is only accessible as return field is used as
a query parameter.
"""
if location is None and query is None and max_features is None:
raise InvalidSearchParameterError(
'Provide either the location or the query parameter or the '
'max_features parameter.'
)
if query is not None:
if not isinstance(query, owslib.fes.OgcExpression):
raise InvalidSearchParameterError(
"Query should be an owslib.fes.OgcExpression.")
filter_request = FilterRequest()
filter_request = filter_request.setConstraint(query)
self._init_fields()
for property_name in filter_request.findall(
'.//{http://www.opengis.net/ogc}PropertyName'):
name = property_name.text
if name not in self._map_df_wfs_source \
and name not in self._wfs_fields:
if name in self._fields:
raise InvalidFieldError(
"Cannot use return field '{}' in query.".format(
name))
raise InvalidFieldError(
"Unknown query parameter: '{}'".format(name))
if location is not None:
self._init_fields()
if sort_by is not None:
if not isinstance(sort_by, owslib.fes.SortBy):
raise InvalidSearchParameterError(
"SortBy should be an owslib.fes.SortBy")
self._init_fields()
for property_name in sort_by.toXML().findall(
'.//{http://www.opengis.net/ogc}PropertyName'):
name = property_name.text
if name not in self._map_df_wfs_source \
and name not in self._wfs_fields:
if name in self._fields:
raise InvalidFieldError(
"Cannot use return field '{}' for sorting.".format(
name))
raise InvalidFieldError(
"Unknown query parameter: '{}'".format(name))
if return_fields is not None:
if type(return_fields) not in (list, tuple, set):
raise AttributeError('return_fields should be a list, '
'tuple or set')
self._init_fields()
for rf in return_fields:
if rf not in self._fields:
if rf in self._map_wfs_source_df:
raise InvalidFieldError(
"Unknown return field: "
"'{}'. Did you mean '{}'?".format(
rf, self._map_wfs_source_df[rf]))
if rf.lower() in [i.lower() for i in
self._map_wfs_source_df.keys()]:
sugg = [i for i in self._map_wfs_source_df.keys() if
i.lower() == rf.lower()][0]
raise InvalidFieldError(
"Unknown return field: "
"'{}'. Did you mean '{}'?".format(rf, sugg))
raise InvalidFieldError(
"Unknown return field: '{}'".format(rf))
def _search(self, location=None, query=None, return_fields=None,
sort_by=None, max_features=None, extra_wfs_fields=[]):
"""Perform the WFS search by issuing a GetFeature request.
Parameters
----------
location : pydov.util.location.AbstractLocationFilter
Location filter limiting the features to retrieve.
query : owslib.fes.OgcExpression
OGC filter expression to use for searching. This can contain any
combination of filter elements defined in owslib.fes. The query
should use the fields provided in `get_fields()`. Note that not
all fields are currently supported as a search parameter.
return_fields : list<str>
A list of fields to be returned in the output data. This should
be a subset of the fields provided in `get_fields()`. Note that
not all fields are currently supported as return fields.
sort_by : owslib.fes.SortBy, optional
List of properties to sort by.
max_features : int
Limit the maximum number of features to request.
extra_wfs_fields: list<str>
A list of extra fields to be included in the WFS requests,
regardless whether they're needed as return field. Optional,
defaults to an empty list.
Returns
-------
etree.Element
XML tree of the WFS response containing the features matching
the location or the query.
Raises
------
pydov.util.errors.InvalidSearchParameterError
When not one of `location`, `query` or `max_features` is provided.
pydov.util.errors.InvalidFieldError
When at least one of the fields in `return_fields` is unknown.
When a field that is only accessible as return field is used as
a query parameter.
When a field that can only be used as a query parameter is used as
a return field.
pydov.util.errors.FeatureOverflowError
When the number of features to be returned is equal to the
maxFeatures limit of the WFS server.
"""
self._pre_search_validation(location, query, sort_by, return_fields,
max_features)
self._init_namespace()
self._init_wfs()
filter_request = None
if query is not None:
filter_request = FilterRequest()
filter_request = filter_request.setConstraint(query)
if filter_request is not None:
for property_name in filter_request.findall(
'.//{http://www.opengis.net/ogc}PropertyName'):
property_name.text = self._map_df_wfs_source.get(
property_name.text, property_name.text)
try:
filter_request = etree.tostring(filter_request,
encoding='unicode')
except LookupError:
# Python2.7 without lxml uses 'utf-8' instead.
filter_request = etree.tostring(filter_request,
encoding='utf-8')
if return_fields is None:
wfs_property_names = [
f['sourcefield'] for f in self._type.get_fields(
source=('wfs',)).values() if not f.get(
'wfs_injected', False)]
else:
wfs_property_names = [self._map_df_wfs_source[i]
for i in self._map_df_wfs_source
if i.startswith('pkey')]
wfs_property_names.extend([self._map_df_wfs_source[i]
for i in self._map_df_wfs_source
if i in return_fields])
wfs_property_names.extend(extra_wfs_fields)
wfs_property_names = list(set(wfs_property_names))
if sort_by is not None:
sort_by_xml = sort_by.toXML()
for property_name in sort_by_xml.findall(
'.//{http://www.opengis.net/ogc}PropertyName'):
property_name.text = self._map_df_wfs_source.get(
property_name.text, property_name.text)
try:
sort_by = etree.tostring(sort_by_xml, encoding='unicode')
except LookupError:
# Python2.7 without lxml uses 'utf-8' instead.
sort_by = etree.tostring(sort_by_xml, encoding='utf-8')
fts = self._get_remote_wfs_feature(
wfs=self.__wfs,
typename=self._layer,
location=location,
filter=filter_request,
sort_by=sort_by,
max_features=max_features,
propertyname=wfs_property_names,
geometry_column=self._geometry_column)
tree = etree.fromstring(fts)
if tree.get('numberOfFeatures') is None:
raise WfsGetFeatureError(
'Error retrieving features from DOV WFS server:\n{}'.format(
etree.tostring(tree).decode('utf8')))
if int(tree.get('numberOfFeatures')) == 10000:
raise FeatureOverflowError(
'Reached the limit of {:d} returned features. Please split up '
'the query to ensure getting all results.'.format(10000))
for hook in pydov.hooks:
hook.wfs_search_result(int(tree.get('numberOfFeatures')))
return tree
def _pre_search_validation(self,
location=None,
query=None,
return_fields=None):
"""Perform validation on the parameters of the search query.
Parameters
----------
location : tuple<minx,miny,maxx,maxy>
The bounding box limiting the features to retrieve.
query : owslib.fes.OgcExpression
OGC filter expression to use for searching. This can contain any
combination of filter elements defined in owslib.fes. The query
should use the fields provided in `get_fields()`. Note that not
all fields are currently supported as a search parameter.
return_fields : list<str> or tuple<str> or set<str>
A list of fields to be returned in the output data. This should
be a subset of the fields provided in `get_fields()`.
Raises
------
pydov.util.errors.InvalidSearchParameterError
When not one of `location` or `query` is provided.
pydov.util.errors.InvalidFieldError
When at least one of the fields in `return_fields` is unknown.
When a field that is only accessible as return field is used as
a query parameter.
"""
if location is None and query is None:
raise InvalidSearchParameterError(
'Provide either the location or the query parameter.')
if query is not None:
if not isinstance(query, owslib.fes.OgcExpression):
raise InvalidSearchParameterError(
"Query should be an owslib.fes.OgcExpression.")
filter_request = FilterRequest()
filter_request = filter_request.setConstraint(query)
self._init_fields()
for property_name in filter_request.findall(
'.//{http://www.opengis.net/ogc}PropertyName'):
name = property_name.text
if name not in self._map_df_wfs_source \
and name not in self._wfs_fields:
if name in self._fields:
raise InvalidFieldError(
"Cannot use return field '%s' in query." % name)
raise InvalidFieldError("Unknown query parameter: '%s'" %
name)
if location is not None:
self._init_fields()
if return_fields is not None:
if type(return_fields) not in (list, tuple, set):
raise AttributeError('return_fields should be a list, '
'tuple or set')
self._init_fields()
for rf in return_fields:
if rf not in self._fields:
if rf in self._map_wfs_source_df:
raise InvalidFieldError(
"Unknown return field: '%s'. Did you mean '%s'?" %
(rf, self._map_wfs_source_df[rf]))
if rf.lower() in [
i.lower() for i in self._map_wfs_source_df.keys()
]:
sugg = [
i for i in self._map_wfs_source_df.keys()
if i.lower() == rf.lower()
][0]
raise InvalidFieldError(
"Unknown return field: '%s'. Did you mean '%s'?" %
(rf, sugg))
raise InvalidFieldError("Unknown return field: '%s'" % rf)