gis: utils module now only imports LayerMapping when GDAL is installed; the `source_srs` keyword lf LayerMapping may now take integer and string parameters (for SRID and WKT spatial references, respectively).

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@6414 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 19 insertions, 5 deletions

diff --git a/django/contrib/gis/utils/__init__.py b/django/contrib/gis/utils/__init__.py
index bdc965556c..65a9987363 100644
--- a/django/contrib/gis/utils/__init__.py
+++ b/django/contrib/gis/utils/__init__.py
@@ -1,6 +1,14 @@
-from django.contrib.gis.utils.layermapping import LayerMapping
+"""
+ This module contains useful utilities for GeoDjango.
+"""
+
 from django.contrib.gis.utils.inspect_data import sample
 
+# Importing LayerMapping (will not be done if GDAL is not installed)
+from django.contrib.gis.gdal import HAS_GDAL
+if HAS_GDAL:
+    from django.contrib.gis.utils.layermapping import LayerMapping
+
 # Importing GeoIP
 try:
     from django.contrib.gis.utils.geoip import GeoIP
diff --git a/django/contrib/gis/utils/layermapping.py b/django/contrib/gis/utils/layermapping.py
index facb4975b3..34092fda5a 100644
--- a/django/contrib/gis/utils/layermapping.py
+++ b/django/contrib/gis/utils/layermapping.py
@@ -30,10 +30,14 @@ Usage:
              geometry type, e.g. 'POINT', 'LINESTRING', 'POLYGON'.
 
 Keyword Args:
-  layer -- The index of the layer to use from the Data Source (defaults to 0)
+  layer: 
+    The index of the layer to use from the Data Source (defaults to 0)
 
-  source_srs -- Use this to specify the source SRS manually (for example, 
-                 some shapefiles don't come with a '.prj' file)
+  source_srs:
+    Use this to specify the source SRS manually (for example, some 
+     shapefiles don't come with a '.prj' file).  A SRID integer, a
+     WKT string, a SpatialReference, and a SpatialRefSys object are
+     all valid parameters here.
 
 Example:
 
@@ -167,7 +171,7 @@ def check_feature(feat, model_fields, mapping):
         else:
             raise Exception, 'Given mapping field "%s" not in given Model fields!' % model_field
 
-        ## Handling if we get a geometry in the Field ###
+        ### Handling if we get a geometry in the Field ###
         if ogr_field in ogc_types:
             # At this time, no more than one geographic field per model =(
             if HAS_GEO:
@@ -218,6 +222,8 @@ def check_srs(layer, source_srs):
         sr = source_srs
     elif isinstance(source_srs, SpatialRefSys):
         sr = source_srs.srs
+    elif isinstance(source_srs, (int, str)):
+        sr = SpatialReference(source_srs)
     else:
         sr = layer.srs
     if not sr: