Now support SVG output in SpatiaLite; added tests for SVG output.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10428 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/db/backend/spatialite/__init__.py

@@ -47,6 +47,7 @@ SpatialBackend = BaseSpatialBackend(name='spatialite', spatialite=True,
                                     point_on_surface=POINT_ON_SURFACE,
                                     scale=SCALE,
                                     select=GEOM_SELECT,
+                                    svg=ASSVG,
                                     sym_difference=SYM_DIFFERENCE,
                                     transform=TRANSFORM,
                                     translate=TRANSLATE,

django/contrib/gis/db/backend/spatialite/query.py

@@ -17,6 +17,7 @@ def get_func(str):
 
 # Functions used by the GeoManager & GeoQuerySet
 AREA = get_func('Area')
+ASSVG = get_func('AsSVG')
 CENTROID = get_func('Centroid')
 CONTAINED = get_func('MbrWithin')
 DIFFERENCE = get_func('Difference')

django/contrib/gis/db/models/query.py

@@ -275,15 +275,26 @@ class GeoQuerySet(QuerySet):
 
         return self._spatial_attribute('snap_to_grid', s, **kwargs)
 
-    def svg(self, **kwargs):
+    def svg(self, relative=False, precision=8, **kwargs):
         """
         Returns SVG representation of the geographic field in a `svg`
         attribute on each element of this GeoQuerySet.
+
+        Keyword Arguments:
+         `relative`  => If set to True, this will evaluate the path in
+                        terms of relative moves (rather than absolute).
+
+         `precision` => May be used to set the maximum number of decimal
+                        digits used in output (defaults to 8).        
         """
+        relative = int(bool(relative))
+        if not isinstance(precision, (int, long)): 
+            raise TypeError('SVG precision keyword argument must be an integer.')
         s = {'desc' : 'SVG',
              'procedure_fmt' : '%(geo_col)s,%(rel)s,%(precision)s',
-             'procedure_args' : {'rel' : int(kwargs.pop('relative', 0)),
-                                 'precision' : kwargs.pop('precision', 8)},
+             'procedure_args' : {'rel' : relative,
+                                 'precision' : precision,
+                                 }
              }
         return self._spatial_attribute('svg', s, **kwargs)
 

django/contrib/gis/tests/geoapp/tests.py

@@ -196,6 +196,19 @@ class GeoModelTest(unittest.TestCase):
         # Finally, we set every available keyword.
         self.assertEqual(City.objects.geojson(bbox=True, crs=True, precision=5).get(name='Chicago').geojson, json)
         
+    @no_oracle
+    def test03d_svg(self):
+        "Testing SVG output using GeoQuerySet.svg()."
+        if DISABLE: return
+        self.assertRaises(TypeError, City.objects.svg, precision='foo')
+        # SELECT AsSVG(geoapp_city.point, 0, 8) FROM geoapp_city WHERE name = 'Pueblo';
+        svg1 = 'cx="-104.609252" cy="-38.255001"'
+        # Even though relative, only one point so it's practically the same except for
+        # the 'c' letter prefix on the x,y values.
+        svg2 = svg1.replace('c', '')
+        self.assertEqual(svg1, City.objects.svg().get(name='Pueblo').svg)
+        self.assertEqual(svg2, City.objects.svg(relative=5).get(name='Pueblo').svg)
+
     def test04_transform(self):
         "Testing the transform() GeoManager method."
         if DISABLE: return
@@ -499,10 +512,8 @@ class GeoModelTest(unittest.TestCase):
             union = union1
         self.assertEqual(True, union.equals_exact(u1, tol))
         self.assertEqual(True, union.equals_exact(u2, tol))
-        # SpatiaLite will segfault trying to union a NULL geometry.
-        if not SpatialBackend.spatialite:
-            qs = City.objects.filter(name='NotACity')
-            self.assertEqual(None, qs.unionagg(field_name='point'))
+        qs = City.objects.filter(name='NotACity')
+        self.assertEqual(None, qs.unionagg(field_name='point'))
 
     @no_spatialite # SpatiaLite does not support abstract geometry columns
     def test18_geometryfield(self):