gis: fixed ticket 4740 with the addition of new exceptions; updated tests for prev change in Field; added get() method to Feature; fixed bug in Layer for geometries w/o srs; SpatialRefSys now uses ellipsoid

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@5587 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/gdal/Feature.py

@@ -93,6 +93,10 @@ class Feature(object):
         return OGRGeomType(lgdal.OGR_FD_GetGeomType(self._fdefn))
     
     #### Feature Methods ####
+    def get(self, field_name):
+        "Returns the value of the field, instead of an instance of the Field object."
+        return self.__getitem__(field_name).value
+
     def index(self, field_name):
         "Returns the index of the given field name."
         i = lgdal.OGR_F_GetFieldIndex(self._feat, c_char_p(field_name))

django/contrib/gis/gdal/Layer.py

@@ -7,6 +7,7 @@ from django.contrib.gis.gdal.libgdal import lgdal
 # Other GDAL imports.
 from django.contrib.gis.gdal.Envelope import Envelope, OGREnvelope
 from django.contrib.gis.gdal.Feature import Feature
+from django.contrib.gis.gdal.OGRGeometry import OGRGeomType
 from django.contrib.gis.gdal.OGRError import OGRException, check_err
 from django.contrib.gis.gdal.SpatialReference import SpatialReference
 
@@ -83,12 +84,16 @@ class Layer(object):
     @property
     def geom_type(self):
         "Returns the geometry type (OGRGeomType) of the Layer."
-        return lgdal.OGR_FD_GetGeomType(self._ldefn)
+        return OGRGeomType(lgdal.OGR_FD_GetGeomType(self._ldefn))
 
     @property
     def srs(self):
         "Returns the Spatial Reference used in this Layer."
-        return SpatialReference(lgdal.OSRClone(lgdal.OGR_L_GetSpatialRef(self._layer)), 'ogr')
+        ptr = lgdal.OGR_L_GetSpatialRef(self._layer)
+        if ptr:
+            srs = SpatialReference(lgdal.OSRClone(ptr), 'ogr')
+        else:
+            return None
 
     @property
     def fields(self):

django/contrib/gis/gdal/OGRGeometry.py

@@ -131,6 +131,14 @@ class OGRGeomType(object):
         return self.__ogr_int[self._index]
 
 #### OGRGeometry Class ####
+class OGRGeometryIndexError(OGRException, KeyError):
+    """This exception is raised when an invalid index is encountered, and has
+    the 'silent_variable_feature' attribute set to true.  This ensures that
+    django's templates proceed to use the next lookup type gracefully when
+    an Exception is raised.  Fixes ticket #4740.
+    """
+    silent_variable_failure = True
+
 class OGRGeometry(object):
     "Generally encapsulates an OGR geometry."
 
@@ -412,7 +420,7 @@ class LineString(OGRGeometry):
             elif self.coord_dim == 3:
                 return (x.value, y.value, z.value)
         else:
-            raise IndexError, 'index out of range'
+            raise OGRGeometryIndexError, 'index out of range: %s' % str(index)
 
     def __iter__(self):
         "Iterates over each point in the LineString."
@@ -445,7 +453,7 @@ class Polygon(OGRGeometry):
     def __getitem__(self, index):
         "Gets the ring at the specified index."
         if index < 0 or index >= self.geom_count:
-            raise IndexError, 'index out of range'
+            raise OGRGeometryIndexError, 'index out of range: %s' % str(index)
         else:
             return OGRGeometry(lgdal.OGR_G_Clone(lgdal.OGR_G_GetGeometryRef(self._g, c_int(index))))
 
@@ -481,7 +489,7 @@ class GeometryCollection(OGRGeometry):
     def __getitem__(self, index):
         "Gets the Geometry at the specified index."
         if index < 0 or index >= self.geom_count:
-            raise IndexError, 'index out of range'
+            raise OGRGeometryIndexError, 'index out of range: %s' % str(index)
         else:
             return OGRGeometry(lgdal.OGR_G_Clone(lgdal.OGR_G_GetGeometryRef(self._g, c_int(index))))
         

django/contrib/gis/geos/GEOSGeometry.py

@@ -85,6 +85,13 @@ else:
 
 # The GEOSException class
 class GEOSException(Exception): pass
+class GEOSGeometryIndexError(GEOSException, KeyError):
+    """This exception is raised when an invalid index is encountered, and has
+    the 'silent_variable_feature' attribute set to true.  This ensures that
+    django's templates proceed to use the next lookup type gracefully when
+    an Exception is raised.  Fixes ticket #4740.
+    """
+    silent_variable_failure = True
 
 # Getting the GEOS C library.  The C interface (CDLL) is used for
 #  both *NIX and Windows.
@@ -345,7 +352,7 @@ class GEOSGeometry(object):
 
     @property
     def envelope(self):
-        "Return the geometries bounding box."
+        "Return the envelope for this geometry (a polygon)."
         return GEOSGeometry(lgeos.GEOSEnvelope(self._g))
 
     @property
@@ -432,7 +439,7 @@ class GEOSCoordSeq(object):
         "Checks the index."
         sz = self.size
         if (sz < 1) or (index < 0) or (index >= sz):
-            raise IndexError, 'index out of range'
+            raise GEOSGeometryIndexError, 'invalid GEOS Geometry index: %s' % str(index)
 
     def _checkdim(self, dim):
         "Checks the given dimension."
@@ -594,7 +601,7 @@ class LineString(GEOSGeometry):
         "Gets the point at the specified index."
         self._cache_cs()
         if index < 0 or index >= self._cs.size:
-            raise IndexError, 'index out of range'
+            raise GEOSGeometryIndexError, 'invalid GEOS Geometry index: %s' % str(index)
         else:
             return self._cs[index]
 
@@ -624,7 +631,7 @@ class Polygon(GEOSGeometry):
         """Returns the ring at the specified index.  The first index, 0, will always
         return the exterior ring.  Indices > 0 will return the interior ring."""
         if index < 0 or index > self.num_interior_rings:
-            raise IndexError, 'index out of range'
+            raise GEOSGeometryIndexError, 'invalid GEOS Geometry index: %s' % str(index)
         else:
             if index == 0:
                 return self.exterior_ring
@@ -687,7 +694,7 @@ class GeometryCollection(GEOSGeometry):
     def _checkindex(self, index):
         "Checks the given geometry index."
         if index < 0 or index >= self.num_geom:
-            raise IndexError, 'index out of range'
+            raise GEOSGeometryIndexError, 'invalid GEOS Geometry index: %s' % str(index)
 
     def __iter__(self):
         "For iteration on the multiple geometries."

django/contrib/gis/models.py

@@ -48,7 +48,7 @@ class SpatialRefSys(models.Model):
         db_table = 'spatial_ref_sys'
 
     def _cache_osr(self):
-        "Caches a GDAL OSR object for this Spatial Reference."
+        "Caches a GDAL OSR SpatialReference object for this SpatialRefSys model."
         if HAS_OSR:
             if not hasattr(self, '_srs'):
                 # Trying to get from WKT first
@@ -71,6 +71,7 @@ class SpatialRefSys(models.Model):
 
     @property
     def srs(self):
+        "Returns the SpatialReference equivalent of this model."
         self._cache_osr()
         return self._srs.clone()
                                                                                 
@@ -79,12 +80,8 @@ class SpatialRefSys(models.Model):
         """Returns a tuple of the ellipsoid parameters:
         (semimajor axis, semiminor axis, and inverse flattening)."""
         if HAS_OSR:
-            # Setting values initially to False
             self._cache_osr()
-            major = self._srs.semi_major
+            return self._srs.ellipsoid
-            minor = self._srs.semi_minor
-            invflat  = self._srs.inverse_flattening
-            return (major, minor, invflat)
         else:
             m = spheroid_regex.match(self.srtext)
             if m: return (float(m.group('major')), float(m.group('flattening')))

django/contrib/gis/tests/test_gdal_ds.py

@@ -101,8 +101,10 @@ class DataSourceTest(unittest.TestCase):
                     for k, v in source.fields.items():
                         fld = feat[k] # Indexing with string value
 
-                        # Asserting the string representation (which asserts the type)
+                        # Asserting the string representation, and making sure we get
-                        self.assertEqual('%s (%s)' % (k, v.__name__), str(fld))
+                        #  the proper OGR Field instance.
+                        self.assertEqual('%s (%s)' % (k, fld.value), str(fld))
+                        self.assertEqual(True, isinstance(fld, v))
 
                     # Testing __iter__ on the Feature
                     for fld in feat: self.assertEqual(fld.name in source.fields.keys(), True)