Add support for topological filters

owslib/feature/postrequest.py

@@ -173,8 +173,12 @@ def set_filter(self, filter):
 
         Cannot be used with set_bbox() or set_featureid().
         """
-        f = etree.fromstring(filter)
-        sub_elem = f.find(util.nspath("Filter", FES_NAMESPACE))
+        if isinstance(filter, str):
+            f = etree.fromstring(filter)
+            sub_elem = f.find(util.nspath("Filter", FES_NAMESPACE))
+        else:
+            sub_elem = filter
+
         self._query.append(sub_elem)
 
     def set_maxfeatures(self, maxfeatures):

owslib/fes2.py

@@ -18,6 +18,7 @@
 from owslib.etree import etree
 from owslib import util
 from owslib.namespaces import Namespaces
+from abc import ABCMeta, abstractmethod
 
 
 # default variables
@@ -391,6 +392,64 @@ def toXML(self):
         return tmp
 
 
+class Filter(OgcExpression):
+    def __init__(self, filter):
+        self.filter = filter
+
+    def toXML(self):
+        node = etree.Element(util.nspath_eval("fes:Filter", namespaces))
+        node.append(self.filter.toXML())
+        return node
+
+
+class TopologicalOpType(OgcExpression, metaclass=ABCMeta):
+    """Abstract base class for topological operators."""
+    @property
+    @abstractmethod
+    def operation(self):
+        """This is a mechanism to ensure this class is subclassed by an actual operation."""
+        pass
+
+    def __init__(self, propertyname, geometry):
+        self.propertyname = propertyname
+        self.geometry = geometry
+
+    def toXML(self):
+        node = etree.Element(util.nspath_eval(f"fes:{self.operation}", namespaces))
+        etree.SubElement(node, util.nspath_eval("fes:ValueReference", namespaces)).text = self.propertyname
+        node.append(self.geometry.toXML())
+
+        return node
+
+
+class Intersects(TopologicalOpType):
+    operation = "Intersects"
+
+
+class Contains(TopologicalOpType):
+    operation = "Contains"
+
+
+class Disjoint(TopologicalOpType):
+    operation = "Disjoint"
+
+
+class Within(TopologicalOpType):
+    operation = "Within"
+
+
+class Touches(TopologicalOpType):
+    operation = "Touches"
+
+
+class Overlaps(TopologicalOpType):
+    operation = "Overlaps"
+
+
+class Equals(TopologicalOpType):
+    operation = "Equals"
+
+
 # BINARY
 class BinaryLogicOpType(OgcExpression):
     """ Binary Operators: And / Or """

owslib/gml.py

@@ -0,0 +1,69 @@
+from dataclasses import dataclass
+from typing import Sequence
+from owslib.etree import etree
+from owslib import util
+from owslib.namespaces import Namespaces
+
+
+def get_namespaces():
+    n = Namespaces()
+    ns = n.get_namespaces(["gml32", "ogc", "xsd"])
+    ns[None] = n.get_namespace("ogc")
+    return ns
+
+
+namespaces = get_namespaces()
+
+
+def prefix(x):
+    """Shorthand to insert namespaces."""
+    return util.nspath_eval(x, namespaces)
+
+
+@dataclass
+class AbstractGMLType():
+    id: str
+
+
+@dataclass
+class AbstractGeometryType(AbstractGMLType):
+    srsName: str = None
+    srsDimension: int = None
+    # axisLabels: str = None
+    # uomLabels: str = None
+
+    description: str = None
+    descriptionReference: str = None
+    identifier: str = None
+    name: str = None
+
+
+@dataclass
+class _PointBase:
+    """This is used to avoid issues arising from non-optional attributes defined after optional attributes."""
+    pos: Sequence[float]
+
+
+@dataclass
+class Point(AbstractGeometryType, _PointBase):
+    """GML Point object."""
+
+    def toXML(self):
+        """Return `lxml.etree.Element` object."""
+        node = etree.Element(prefix("gml32:Point"))
+        for key in ["id", "srsName"]:
+            if getattr(self, key, None) is not None:
+                node.set(prefix(f"gml32:{key}"), getattr(self, key))
+
+        for key in ["description", "descriptionReference", "identifier", "name"]:
+            content = getattr(self, key)
+            if content is not None:
+                etree.SubElement(node, prefix(f"gml32:{key}")).text = content
+
+        coords = etree.SubElement(node, prefix("gml32:pos"))
+        coords.text = " ".join([str(c) for c in self.pos])
+        for key in ["srsDimension"]:
+            if getattr(self, key, None) is not None:
+                node.set(prefix(f"gml32:{key}"), getattr(self, key))
+
+        return node

owslib/iso.py

@@ -548,7 +548,8 @@ def __init__(self, md=None, identtype=None):
             self.status = _testCodeListValue(md.find(util.nspath_eval('gmd:status/gmd:MD_ProgressCode', namespaces)))
 
             self.graphicoverview = []
-            for val in md.findall(util.nspath_eval('gmd:graphicOverview/gmd:MD_BrowseGraphic/gmd:fileName/gco:CharacterString', namespaces)):
+            for val in md.findall(util.nspath_eval(
+                    'gmd:graphicOverview/gmd:MD_BrowseGraphic/gmd:fileName/gco:CharacterString', namespaces)):
                 if val is not None:
                     val2 = util.testXMLValue(val)
                     if val2 is not None:

requirements.txt

@@ -3,3 +3,4 @@ pytz
 requests>=1.0
 pyproj >=2
 pyyaml
+dataclasses; python_version < '3.7'

tests/test_fes2.py

@@ -0,0 +1,46 @@
+import pytest
+from owslib.wfs import WebFeatureService
+from owslib import fes2
+from owslib.gml import Point
+from owslib.namespaces import Namespaces
+from owslib import util
+import json
+
+n = Namespaces()
+FES_NAMESPACE = n.get_namespace("fes")
+GML32_NAMESPACE = n.get_namespace("gml32")
+
+
+SERVICE_URL = "http://soggy.zoology.ubc.ca:8080/geoserver/wfs"
+
+
+def test_raw_filter():
+    """Just inspect the filter object (not embedded in a getfeature request)."""
+    point = Point(id="qc", srsName="http://www.opengis.net/gml/srs/epsg.xml#4326", pos=[-71, 46])
+    f = fes2.Filter(
+        fes2.And([fes2.Intersects(propertyname="the_geom", geometry=point),
+                  fes2.PropertyIsLike("name", "value")]
+                 )
+    )
+
+    xml = f.toXML()
+
+    # Fairly basic test
+    xml.find(util.nspath("Filter", FES_NAMESPACE))
+    xml.find(util.nspath("And", FES_NAMESPACE))
+    xml.find(util.nspath("Intersects", FES_NAMESPACE))
+    xml.find(util.nspath("Point", GML32_NAMESPACE))
+
+
+@pytest.mark.online
+def test_filter():
+    """A request without filtering will yield 600 entries. With filtering we expect only one.
+
+    Note that this type of topological filtering only works (so far) with WFS 2.0.0 and POST requests.
+    """
+    wfs = WebFeatureService(SERVICE_URL, version="2.0.0")
+    layer = "bcmca:commercialfish_crab"
+    point = Point(id="random", srsName="http://www.opengis.net/gml/srs/epsg.xml#4326", pos=[-129.8, 55.44])
+    f = fes2.Filter(fes2.Contains(propertyname="geom", geometry=point))
+    r = wfs.getfeature(layer, outputFormat="application/json", method="POST", filter=f.toXML())
+    assert json.load(r)["totalFeatures"] == 1

tests/test_wfs_generic.py

@@ -2,7 +2,7 @@
 from owslib.util import ServiceException
 from urllib.parse import urlparse
 from tests.utils import resource_file, sorted_url_query, service_ok
-
+import json
 import pytest
 
 SERVICE_URL = 'https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288'
@@ -54,7 +54,6 @@ def test_getfeature():
 @pytest.mark.skipif(not service_ok(SERVICE_URL),
                     reason="WFS service is unreachable")
 def test_outputformat_wfs_100():
-    import json
     wfs = WebFeatureService('https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
                             version='1.0.0')
     feature = wfs.getfeature(
@@ -66,7 +65,6 @@ def test_outputformat_wfs_100():
 @pytest.mark.skipif(not service_ok(SERVICE_URL),
                     reason="WFS service is unreachable")
 def test_outputformat_wfs_110():
-    import json
     wfs = WebFeatureService('https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
                             version='1.1.0')
     feature = wfs.getfeature(
@@ -78,7 +76,6 @@ def test_outputformat_wfs_110():
 @pytest.mark.skipif(not service_ok(SERVICE_URL),
                     reason="WFS service is unreachable")
 def test_outputformat_wfs_200():
-    import json
     wfs = WebFeatureService('https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
                             version='2.0.0')
     feature = wfs.getfeature(
@@ -90,7 +87,6 @@ def test_outputformat_wfs_200():
 @pytest.mark.skipif(not service_ok(SERVICE_URL),
                     reason="WFS service is unreachable")
 def test_srsname_wfs_100():
-    import json
     wfs = WebFeatureService('https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
                             version='1.0.0')
     # ServiceException: Unable to support srsName: EPSG:99999999
@@ -99,7 +95,6 @@ def test_srsname_wfs_100():
             typename=['sb:Project_Area'], maxfeatures=1, propertyname=None, outputFormat='application/json',
             srsname="EPSG:99999999")
 
-    import json
     wfs = WebFeatureService('https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
                             version='1.0.0')
     feature = wfs.getfeature(
@@ -112,7 +107,6 @@ def test_srsname_wfs_100():
 @pytest.mark.skipif(not service_ok(SERVICE_URL),
                     reason="WFS service is unreachable")
 def test_srsname_wfs_110():
-    import json
     wfs = WebFeatureService(
         'https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
         version='1.1.0')
@@ -122,7 +116,6 @@ def test_srsname_wfs_110():
             typename=['sb:Project_Area'], maxfeatures=1, propertyname=None, outputFormat='application/json',
             srsname="EPSG:99999999")
 
-    import json
     wfs = WebFeatureService(
         'https://www.sciencebase.gov/catalogMaps/mapping/ows/53398e51e4b0db25ad10d288',
         version='1.0.0')