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import cgi
from owslib.etree import etree
from datetime import datetime
from urllib import urlencode
from owslib import ows
from owslib.crs import Crs
from owslib.fes import FilterCapabilities200
from owslib.util import openURL, testXMLValue, nspath_eval, nspath, extract_time
from owslib.namespaces import Namespaces
def get_namespaces():
n = Namespaces()
ns = n.get_namespaces(["fes","ogc","om","gml32","sml","swe20","swes","xlink"])
ns["ows"] = n.get_namespace("ows110")
ns["sos"] = n.get_namespace("sos20")
return ns
namespaces = get_namespaces()
class SensorObservationService_2_0_0(object):
"""
Abstraction for OGC Sensor Observation Service (SOS).
Implements ISensorObservationService.
"""
def __new__(self,url, version, xml=None, username=None, password=None):
"""overridden __new__ method"""
obj=object.__new__(self)
obj.__init__(url, version, xml, username, password)
return obj
def __getitem__(self,id):
''' check contents dictionary to allow dict like access to service observational offerings'''
if name in self.__getattribute__('contents').keys():
return self.__getattribute__('contents')[id]
else:
raise KeyError, "No Observational Offering with id: %s" % id
def __init__(self, url, version='2.0.0', xml=None, username=None, password=None):
"""Initialize."""
self.url = url
self.username = username
self.password = password
self.version = version
self._capabilities = None
# Authentication handled by Reader
reader = SosCapabilitiesReader(
version=self.version, url=self.url, username=self.username, password=self.password
)
if xml: # read from stored xml
self._capabilities = reader.read_string(xml)
else: # read from server
self._capabilities = reader.read(self.url)
# Avoid building metadata if the response is an Exception
se = self._capabilities.find(nspath_eval('ows:ExceptionReport', namespaces))
if se is not None:
raise ows.ExceptionReport(se)
# build metadata objects
self._build_metadata()
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def getOperationByName(self, name):
"""Return a named content item."""
for item in self.operations:
if item.name == name:
return item
raise KeyError("No operation named %s" % name)
def _build_metadata(self):
"""
Set up capabilities metadata objects
"""
# ows:ServiceIdentification metadata
service_id_element = self._capabilities.find(nspath_eval('ows:ServiceIdentification', namespaces))
self.identification = ows.ServiceIdentification(service_id_element)
# ows:ServiceProvider metadata
service_provider_element = self._capabilities.find(nspath_eval('ows:ServiceProvider', namespaces))
self.provider = ows.ServiceProvider(service_provider_element)
# ows:OperationsMetadata metadata
self.operations= []
for elem in self._capabilities.findall(nspath_eval('ows:OperationsMetadata/ows:Operation', namespaces)):
self.operations.append(ows.OperationsMetadata(elem))
# sos:FilterCapabilities
filters = self._capabilities.find(nspath_eval('sos:Filter_Capabilities', namespaces))
if filters is not None:
self.filters = FilterCapabilities200(filters)
else:
self.filters = None
# sos:Contents metadata
self.contents = {}
self.offerings = []
for offering in self._capabilities.findall(nspath_eval('sos:contents/sos:Contents/swes:offering/sos:ObservationOffering', namespaces)):
off = SosObservationOffering(offering)
self.contents[off.id] = off
self.offerings.append(off)
def describe_sensor(self, outputFormat=None,
procedure=None,
method='Get',
**kwargs):
try:
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base_url = next((m.get('url') for m in self.getOperationByName('DescribeSensor').methods if m.get('type').lower() == method.lower()))
except StopIteration:
base_url = self.url
request = {'service': 'SOS', 'version': self.version, 'request': 'DescribeSensor'}
# Required Fields
assert isinstance(outputFormat, str)
request['procedureDescriptionFormat'] = outputFormat
assert isinstance(procedure, str)
request['procedure'] = procedure
# Optional Fields
if kwargs:
for kw in kwargs:
request[kw]=kwargs[kw]
data = urlencode(request)
response = openURL(base_url, data, method, username=self.username, password=self.password).read()
tr = etree.fromstring(response)
if tr.tag == nspath_eval("ows:ExceptionReport", namespaces):
raise ows.ExceptionReport(tr)
return response
def get_observation(self, responseFormat=None,
offerings=None,
observedProperties=None,
eventTime=None,
method='Get',
**kwargs):
"""
Parameters
----------
format : string
Output format. Provide one that is available for all offerings
method : string
Optional. HTTP DCP method name: Get or Post. Must
**kwargs : extra arguments
anything else e.g. vendor specific parameters
"""
base_url = self.get_operation_by_name('GetObservation').methods[method]['url']
request = {'service': 'SOS', 'version': self.version, 'request': 'GetObservation'}
# Required Fields
assert isinstance(offerings, list) and len(offerings) > 0
request['offering'] = ','.join(offerings)
assert isinstance(observedProperties, list) and len(observedProperties) > 0
request['observedProperty'] = ','.join(observedProperties)
if responseFormat is not None:
request['responseFormat'] = responseFormat
# Optional Fields
if eventTime is not None:
request['temporalFilter'] = eventTime
if kwargs:
for kw in kwargs:
request[kw]=kwargs[kw]
data = urlencode(request)
response = openURL(base_url, data, method, username=self.username, password=self.password).read()
try:
tr = etree.fromstring(response)
if tr.tag == nspath_eval("ows:ExceptionReport", namespaces):
raise ows.ExceptionReport(tr)
else:
return response
except ows.ExceptionReport:
raise
except BaseException:
return response
def get_operation_by_name(self, name):
"""
Return a Operation item by name, case insensitive
"""
for item in self.operations:
if item.name.lower() == name.lower():
return item
raise KeyError, "No Operation named %s" % name
class SosObservationOffering(object):
def __init__(self, element):
self._root = element
self.id = testXMLValue(self._root.find(nspath_eval('swes:identifier', namespaces)))
if self.id is None:
self.id = testXMLValue(self._root.attrib.get(nspath_eval('swes:id', namespaces)), True)
self.description = testXMLValue(self._root.find(nspath_eval('swes:description', namespaces)))
self.name = testXMLValue(self._root.find(nspath_eval('swes:name', namespaces)))
# sos:observedArea
try:
envelope = self._root.find(nspath_eval('sos:observedArea/gml32:Envelope', namespaces))
lower_left_corner = testXMLValue(envelope.find(nspath_eval('gml32:lowerCorner', namespaces))).split()
upper_right_corner = testXMLValue(envelope.find(nspath_eval('gml32:upperCorner', namespaces))).split()
# (left, bottom, right, top) in self.bbox_srs units
self.bbox = (float(lower_left_corner[1]), float(lower_left_corner[0]), float(upper_right_corner[1]), float(upper_right_corner[0]))
self.bbox_srs = Crs(testXMLValue(envelope.attrib.get('srsName'), True))
except Exception, err:
self.bbox = None
self.bbox_srs = None
# LOOK: Support all gml:TimeGeometricPrimitivePropertyType
# Right now we are just supporting gml:TimePeriod
# sos:Time
begin_position_element = self._root.find(nspath_eval('sos:phenomenonTime/gml32:TimePeriod/gml32:beginPosition', namespaces))
self.begin_position = extract_time(begin_position_element)
end_position_element = self._root.find(nspath_eval('sos:phenomenonTime/gml32:TimePeriod/gml32:endPosition', namespaces))
self.end_position = extract_time(end_position_element)
self.procedures = []
for proc in self._root.findall(nspath_eval('swes:procedure', namespaces)):
self.procedures.append(testXMLValue(proc))
self.procedure_description_formats = []
for proc in self._root.findall(nspath_eval('swes:procedureDescriptionFormat', namespaces)):
self.procedure_description_formats.append(testXMLValue(proc))
# LOOK: Support swe:Phenomenon here
# this includes compound properties
self.observed_properties = []
for op in self._root.findall(nspath_eval('swes:observableProperty', namespaces)):
self.observed_properties.append(testXMLValue(op))
self.features_of_interest = []
for fot in self._root.findall(nspath_eval('sos:featureOfInterest', namespaces)):
self.features_of_interest.append(testXMLValue(fot.attrib.get(nspath_eval('xlink:href', namespaces)), True))
self.response_formats = []
for rf in self._root.findall(nspath_eval('sos:responseFormat', namespaces)):
self.response_formats.append(testXMLValue(rf))
self.observation_models = []
for om in self._root.findall(nspath_eval('sos:observationType', namespaces)):
self.observation_models.append(testXMLValue(om))
def __str__(self):
return 'Offering id: %s, name: %s' % (self.id, self.name)
class SosCapabilitiesReader(object):
def __init__(self, version="2.0.0", url=None, username=None, password=None):
self.version = version
self.url = url
self.username = username
self.password = password
def capabilities_url(self, service_url):
"""
Return a capabilities url
"""
qs = []
if service_url.find('?') != -1:
qs = cgi.parse_qsl(service_url.split('?')[1])
params = [x[0] for x in qs]
if 'service' not in params:
qs.append(('service', 'SOS'))
if 'request' not in params:
qs.append(('request', 'GetCapabilities'))
if 'acceptversions' not in params:
qs.append(('acceptversions', self.version))
urlqs = urlencode(tuple(qs))
return service_url.split('?')[0] + '?' + urlqs
def read(self, service_url):
"""
Get and parse a WMS capabilities document, returning an
elementtree instance
service_url is the base url, to which is appended the service,
version, and request parameters
"""
getcaprequest = self.capabilities_url(service_url)
spliturl=getcaprequest.split('?')
u = openURL(spliturl[0], spliturl[1], method='Get', username=self.username, password=self.password)
return etree.fromstring(u.read())
def read_string(self, st):
"""
Parse a SOS capabilities document, returning an elementtree instance
st should be an XML capabilities document
"""
if not isinstance(st, str):
raise ValueError("String must be of type string, not %s" % type(st))
return etree.fromstring(st)