# -*- coding: ISO-8859-15 -*-
# =============================================================================
# Copyright (c) 2011 Tom Kralidis
#
# Authors : Tom Kralidis <tomkralidis@gmail.com>
#
# Contact email: tomkralidis@gmail.com
# =============================================================================
from __future__ import (absolute_import, division, print_function)
import cgi
from six import PY2
from six.moves import cStringIO as StringIO
try:
from urllib import urlencode
except ImportError:
from urllib.parse import urlencode
from owslib.util import openURL, testXMLValue, nspath_eval, ServiceException
from owslib.etree import etree
from owslib.fgdc import Metadata
from owslib.iso import MD_Metadata
from owslib.ows import *
from owslib.fes import *
from owslib.crs import Crs
from owslib.feature import WebFeatureService_
from owslib.namespaces import Namespaces
from owslib.util import log
def get_namespaces():
n = Namespaces()
return n.get_namespaces(["gml","ogc","ows","wfs"])
namespaces = get_namespaces()
class WebFeatureService_1_1_0(WebFeatureService_):
"""Abstraction for OGC Web Feature Service (WFS).
Implements IWebFeatureService.
"""
def __new__(self,url, version, xml, parse_remote_metadata=False, timeout=30):
""" overridden __new__ method
@type url: string
@param url: url of WFS capabilities document
@type xml: string
@param xml: elementtree object
@type parse_remote_metadata: boolean
@param parse_remote_metadata: whether to fully process MetadataURL elements
@param timeout: time (in seconds) after which requests should timeout
@return: initialized WebFeatureService_1_1_0 object
"""
obj=object.__new__(self)
obj.__init__(url, version, xml, parse_remote_metadata, timeout)
return obj
def __getitem__(self,name):
''' check contents dictionary to allow dict like access to service layers'''
if name in self.__getattribute__('contents').keys():
return self.__getattribute__('contents')[name]
else:
raise KeyError("No content named %s" % name)
def __init__(self, url, version, xml=None, parse_remote_metadata=False, timeout=30):
"""Initialize."""
self.url = url
self.version = version
self.timeout = timeout
self._capabilities = None
self.owscommon = OwsCommon('1.0.0')
reader = WFSCapabilitiesReader(self.version)
if xml:
self._capabilities = reader.readString(xml)
else:
self._capabilities = reader.read(self.url)
self._buildMetadata(parse_remote_metadata)
def _buildMetadata(self, parse_remote_metadata=False):
'''set up capabilities metadata objects: '''
# ServiceIdentification
val = self._capabilities.find(util.nspath_eval('ows:ServiceIdentification', namespaces))
self.identification=ServiceIdentification(val,self.owscommon.namespace)
# ServiceProvider
val = self._capabilities.find(util.nspath_eval('ows:ServiceProvider', namespaces))
self.provider=ServiceProvider(val,self.owscommon.namespace)
# ServiceOperations metadata
self.operations=[]
for elem in self._capabilities.findall(util.nspath_eval('ows:OperationsMetadata/ows:Operation', namespaces)):
self.operations.append(OperationsMetadata(elem, self.owscommon.namespace))
# FilterCapabilities
val = self._capabilities.find(util.nspath_eval('ogc:Filter_Capabilities', namespaces))
self.filters=FilterCapabilities(val)
#serviceContents metadata: our assumption is that services use a top-level
#layer as a metadata organizer, nothing more.
self.contents={}
features = self._capabilities.findall(nspath_eval('wfs:FeatureTypeList/wfs:FeatureType', namespaces))
for feature in features:
cm=ContentMetadata(feature, parse_remote_metadata)
self.contents[cm.id]=cm
#exceptions
self.exceptions = [f.text for f \
in self._capabilities.findall('Capability/Exception/Format')]
def getcapabilities(self):
"""Request and return capabilities document from the WFS as a
file-like object.
NOTE: this is effectively redundant now"""
reader = WFSCapabilitiesReader(self.version)
return openURL(reader.capabilities_url(self.url), timeout=self.timeout)
def items(self):
'''supports dict-like items() access'''
items=[]
for item in self.contents:
items.append((item,self.contents[item]))
return items
def _makeStringIO(self, strval):
"""
Helper method to make sure the StringIO being returned will work.
Differences between Python 2.6/2.7/3.x mean we have a lot of cases to handle.
"""
if PY2:
return StringIO(strval)
return StringIO(strval.decode())
def getfeature(self, typename=None, filter=None, bbox=None, featureid=None,
featureversion=None, propertyname='*', maxfeatures=None,
srsname=None, outputFormat=None, method='Get',
startindex=None):
"""Request and return feature data as a file-like object.
Parameters
----------
typename : list
List of typenames (string)
filter : string
XML-encoded OGC filter expression.
bbox : tuple
(left, bottom, right, top) in the feature type's coordinates.
featureid : list
List of unique feature ids (string)
featureversion : string
Default is most recent feature version.
propertyname : list
List of feature property names. '*' matches all.
maxfeatures : int
Maximum number of features to be returned.
method : string
Qualified name of the HTTP DCP method to use.
srsname: string
EPSG code to request the data in
outputFormat: string (optional)
Requested response format of the request.
startindex: int (optional)
Start position to return feature set (paging in combination with maxfeatures)
There are 3 different modes of use
1) typename and bbox (simple spatial query). It is assumed, that
bbox coordinates are given *always* in the east,north order
2) typename and filter (more expressive)
3) featureid (direct access to known features)
"""
try:
base_url = next((m.get('url') for m in self.getOperationByName('GetFeature').methods if m.get('type').lower() == method.lower()))
except StopIteration:
base_url = self.url
request = {'service': 'WFS', 'version': self.version, 'request': 'GetFeature'}
if not isinstance(typename, list):
typename = [typename]
if srsname is not None:
# check, if desired SRS is supported by the service for this typename
if typename is not None:
# convert srsname string to Crs object found in GetCaps
srsnameobj = self.getSRS(srsname, typename[0])
if srsnameobj is not None:
request['srsname'] = srsnameobj.id
else:
options = ", ".join(map(lambda x: x.id, self.contents[typename[0]].crsOptions))
raise ServiceException("SRSNAME %s not supported. Options: %s" % (srsname, options))
else:
request['srsname'] = str(srsname)
# check featureid
if featureid:
request['featureid'] = ','.join(featureid)
# bbox
elif bbox and typename:
request["bbox"] = self.getBBOXKVP(bbox, typename)
# or filter
elif filter and typename:
request['filter'] = str(filter)
assert len(typename) > 0
request['typename'] = ','.join(typename)
if propertyname is not None:
if not isinstance(propertyname, list):
propertyname = [propertyname]
request['propertyname'] = ','.join(propertyname)
if featureversion is not None:
request['featureversion'] = str(featureversion)
if maxfeatures is not None:
request['maxfeatures'] = str(maxfeatures)
if startindex is not None:
request['startindex'] = str(startindex)
if outputFormat is not None:
request["outputFormat"] = outputFormat
data = urlencode(request)
log.debug("Making request: %s?%s" % (base_url, data))
u = openURL(base_url, data, method, timeout=self.timeout)
# check for service exceptions, rewrap, and return
# We're going to assume that anything with a content-length > 32k
# is data. We'll check anything smaller.
if 'Content-Length' in u.info():
length = int(u.info()['Content-Length'])
have_read = False
else:
data = u.read()
have_read = True
length = len(data)
if length < 32000:
if not have_read:
data = u.read()
try:
tree = etree.fromstring(data)
except BaseException:
# Not XML
return self._makeStringIO(data)
else:
if tree.tag == "{%s}ServiceExceptionReport" % namespaces["ogc"]:
se = tree.find(nspath_eval('ServiceException', namespaces["ogc"]))
raise ServiceException(str(se.text).strip())
else:
return self._makeStringIO(data)
else:
if have_read:
return self._makeStringIO(data)
return u
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)
class ContentMetadata:
"""Abstraction for WFS metadata.
Implements IMetadata.
"""
def __init__(self, elem, parse_remote_metadata=False, timeout=30):
"""."""
self.id = testXMLValue(elem.find(nspath_eval('wfs:Name', namespaces)))
self.title = testXMLValue(elem.find(nspath_eval('wfs:Title', namespaces)))
self.abstract = testXMLValue(elem.find(nspath_eval('wfs:Abstract', namespaces)))
self.keywords = [f.text for f in elem.findall(nspath_eval('ows:Keywords/ows:Keyword', namespaces))]
# bbox
self.boundingBoxWGS84 = None
b = BoundingBox(elem.find(nspath_eval('ows:WGS84BoundingBox', namespaces)), namespaces['ows'])
if b is not None:
self.boundingBoxWGS84 = (
float(b.minx), float(b.miny),
float(b.maxx), float(b.maxy),
)
# crs options
self.crsOptions = [Crs(srs.text) for srs in elem.findall(nspath_eval('wfs:OtherSRS', namespaces))]
dsrs = testXMLValue(elem.find(nspath_eval('wfs:DefaultSRS', namespaces)))
if dsrs is not None: # first element is default srs
self.crsOptions.insert(0, Crs(dsrs))
# verbs
self.verbOptions = [op.text for op in elem.findall(nspath_eval('wfs:Operations/wfs:Operation', namespaces))]
# output formats
self.outputFormats = [op.text for op in elem.findall(nspath_eval('wfs:OutputFormats/wfs:Format', namespaces))]
# MetadataURLs
self.metadataUrls = []
for m in elem.findall(nspath_eval('wfs:MetadataURL', namespaces)):
metadataUrl = {
'type': testXMLValue(m.attrib['type'], attrib=True),
'format': testXMLValue(m.find('Format')),
'url': testXMLValue(m)
}
if metadataUrl['url'] is not None and parse_remote_metadata: # download URL
try:
content = openURL(metadataUrl['url'], timeout=timeout)
doc = etree.parse(content)
if metadataUrl['type'] is not None:
if metadataUrl['type'] == 'FGDC':
metadataUrl['metadata'] = Metadata(doc)
if metadataUrl['type'] in ['TC211', '19115', '19139']:
metadataUrl['metadata'] = MD_Metadata(doc)
except Exception:
metadataUrl['metadata'] = None
self.metadataUrls.append(metadataUrl)
#others not used but needed for iContentMetadata harmonisation
self.styles=None
self.timepositions=None
self.defaulttimeposition=None
class WFSCapabilitiesReader(object):
"""Read and parse capabilities document into a lxml.etree infoset
"""
def __init__(self, version='1.0'):
"""Initialize"""
self.version = version
self._infoset = None
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', 'WFS'))
if 'request' not in params:
qs.append(('request', 'GetCapabilities'))
if 'version' not in params:
qs.append(('version', self.version))
urlqs = urlencode(tuple(qs))
return service_url.split('?')[0] + '?' + urlqs
def read(self, url, timeout=30):
"""Get and parse a WFS capabilities document, returning an
instance of WFSCapabilitiesInfoset
Parameters
----------
url : string
The URL to the WFS capabilities document.
timeout : number
A timeout value (in seconds) for the request.
"""
request = self.capabilities_url(url)
u = openURL(request, timeout=timeout)
return etree.fromstring(u.read())
def readString(self, st):
"""Parse a WFS capabilities document, returning an
instance of WFSCapabilitiesInfoset
string should be an XML capabilities document
"""
if not isinstance(st, str) and not isinstance(st, bytes):
raise ValueError("String must be of type string or bytes, not %s" % type(st))
return etree.fromstring(st)