gis: gdal: Fixed GDAL version string parsing for development versions; GEOJSON constant now in root module; added extent property and coords property alias for tuple; added x,y,z properties for OGR LineStrings.

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@7113 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/gdal/__init__.py

@@ -28,10 +28,10 @@ try:
     from django.contrib.gis.gdal.datasource import DataSource
     from django.contrib.gis.gdal.libgdal import gdal_version, gdal_full_version, gdal_release_date
     from django.contrib.gis.gdal.srs import SpatialReference, CoordTransform
-    from django.contrib.gis.gdal.geometries import OGRGeometry
+    from django.contrib.gis.gdal.geometries import OGRGeometry, GEOJSON
     HAS_GDAL = True
 except:
-    HAS_GDAL = False
+    HAS_GDAL, GEOJSON = False, False
 
 # The envelope, error, and geomtype modules do not actually require the
 #  GDAL library.

django/contrib/gis/gdal/geometries.py

@@ -216,8 +216,14 @@ class OGRGeometry(object):
     @property
     def envelope(self):
         "Returns the envelope for this Geometry."
+        # TODO: Fix Envelope() for Point geometries.
         return Envelope(get_envelope(self._ptr, byref(OGREnvelope())))
 
+    @property
+    def extent(self):
+        "Returns the envelope as a 4-tuple, instead of as an Envelope object."
+        return self.envelope.tuple
+
     #### SpatialReference-related Properties ####
     
     # The SRS property
@@ -446,7 +452,8 @@ class Point(OGRGeometry):
     @property
     def z(self):
         "Returns the Z coordinate for this Point."
-        return getz(self._ptr, 0)
+        if self.coord_dim == 3:
+            return getz(self._ptr, 0)
 
     @property
     def tuple(self):
@@ -455,6 +462,7 @@ class Point(OGRGeometry):
             return (self.x, self.y)
         elif self.coord_dim == 3:
             return (self.x, self.y, self.z)
+    coords = tuple
 
 class LineString(OGRGeometry):
 
@@ -485,7 +493,31 @@ class LineString(OGRGeometry):
     @property
     def tuple(self):
         "Returns the tuple representation of this LineString."
-        return tuple(self[i] for i in xrange(len(self)))
+        return tuple([self[i] for i in xrange(len(self))])
+    coords = tuple
+
+    def _listarr(self, func):
+        """
+        Internal routine that returns a sequence (list) corresponding with
+        the given function.
+        """
+        return [func(self._ptr, i) for i in xrange(len(self))]
+
+    @property
+    def x(self):
+        "Returns the X coordinates in a list."
+        return self._listarr(getx)
+
+    @property
+    def y(self):
+        "Returns the Y coordinates in a list."
+        return self._listarr(gety)
+    
+    @property
+    def z(self):
+        "Returns the Z coordinates in a list."
+        if self.coord_dim == 3:
+            return self._listarr(getz)
 
 # LinearRings are used in Polygons.
 class LinearRing(LineString): pass
@@ -513,11 +545,13 @@ class Polygon(OGRGeometry):
     def shell(self):
         "Returns the shell of this Polygon."
         return self[0] # First ring is the shell
+    exterior_ring = shell
 
     @property
     def tuple(self):
         "Returns a tuple of LinearRing coordinate tuples."
-        return tuple(self[i].tuple for i in xrange(self.geom_count))
+        return tuple([self[i].tuple for i in xrange(self.geom_count)])
+    coords = tuple
 
     @property
     def point_count(self):
@@ -575,7 +609,8 @@ class GeometryCollection(OGRGeometry):
     @property
     def tuple(self):
         "Returns a tuple representation of this Geometry Collection."
-        return tuple(self[i].tuple for i in xrange(self.geom_count)) 
+        return tuple([self[i].tuple for i in xrange(self.geom_count)])
+    coords = tuple
 
 # Multiple Geometry types.
 class MultiPoint(GeometryCollection): pass

django/contrib/gis/gdal/prototypes/geom.py

@@ -8,8 +8,8 @@ from django.contrib.gis.gdal.prototypes.generation import \
     srs_output, string_output, void_output
 
 # Some prototypes need to be aware of what version GDAL we have.
-major, minor1, minor2 = map(int, gdal_version().split('.'))
-if major <= 1 and minor1 <= 4:
+major, minor = map(int, gdal_version().split('.')[:2])
+if major <= 1 and minor <= 4:
     GEOJSON = False
 else:
     GEOJSON = True

django/contrib/gis/tests/test_gdal_geom.py

@@ -117,6 +117,12 @@ class OGRGeomTest(unittest.TestCase):
             self.assertRaises(OGRIndexError, linestr.__getitem__, len(linestr))
             prev = linestr
 
+            # Testing the x, y properties.
+            x = [tmpx for tmpx, tmpy in ls.tup]
+            y = [tmpy for tmpx, tmpy in ls.tup]
+            self.assertEqual(x, linestr.x)
+            self.assertEqual(y, linestr.y)
+
     def test05_multilinestring(self):
         "Testing MultiLineString objects."
         prev = OGRGeometry('POINT(0 0)')
@@ -354,6 +360,19 @@ class OGRGeomTest(unittest.TestCase):
             mp3.add(mpoly) # Adding a MultiPolygon's entire contents at once.
             for tmp in (mp1, mp2, mp3): self.assertEqual(mpoly, tmp)
 
+    def test15_extent(self):
+        "Testing `extent` property."
+        # The xmin, ymin, xmax, ymax of the MultiPoint should be returned.
+        mp = OGRGeometry('MULTIPOINT(5 23, 0 0, 10 50)')
+        self.assertEqual((0.0, 0.0, 10.0, 50.0), mp.extent)
+        # Testing on the 'real world' Polygon.
+        poly = OGRGeometry(polygons[3].wkt)
+        ring = poly.shell
+        x, y = ring.x, ring.y
+        xmin, ymin = min(x), min(y)
+        xmax, ymax = max(x), max(y)
+        self.assertEqual((xmin, ymin, xmax, ymax), poly.extent)
+
 def suite():
     s = unittest.TestSuite()
     s.addTest(unittest.makeSuite(OGRGeomTest))