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Diffstat (limited to 'django/contrib/gis/models.py')
| -rw-r--r-- | django/contrib/gis/models.py | 233 |
1 files changed, 0 insertions, 233 deletions
diff --git a/django/contrib/gis/models.py b/django/contrib/gis/models.py index e24ca8e3e1..e69de29bb2 100644 --- a/django/contrib/gis/models.py +++ b/django/contrib/gis/models.py @@ -1,233 +0,0 @@ -""" - Imports the SpatialRefSys and GeometryColumns models dependent on the - spatial database backend. -""" -import re -from django.conf import settings - -# Checking for the presence of GDAL (needed for the SpatialReference object) -from django.contrib.gis.gdal import HAS_GDAL, PYTHON23 -if HAS_GDAL: - from django.contrib.gis.gdal import SpatialReference - -class SpatialRefSysMixin(object): - """ - The SpatialRefSysMixin is a class used by the database-dependent - SpatialRefSys objects to reduce redundnant code. - """ - # For pulling out the spheroid from the spatial reference string. This - # regular expression is used only if the user does not have GDAL installed. - # TODO: Flattening not used in all ellipsoids, could also be a minor axis, - # or 'b' parameter. - spheroid_regex = re.compile(r'.+SPHEROID\[\"(?P<name>.+)\",(?P<major>\d+(\.\d+)?),(?P<flattening>\d{3}\.\d+),') - - # For pulling out the units on platforms w/o GDAL installed. - # TODO: Figure out how to pull out angular units of projected coordinate system and - # fix for LOCAL_CS types. GDAL should be highly recommended for performing - # distance queries. - units_regex = re.compile(r'.+UNIT ?\["(?P<unit_name>[\w \'\(\)]+)", ?(?P<unit>[\d\.]+)(,AUTHORITY\["(?P<unit_auth_name>[\w \'\(\)]+)","(?P<unit_auth_val>\d+)"\])?\]([\w ]+)?(,AUTHORITY\["(?P<auth_name>[\w \'\(\)]+)","(?P<auth_val>\d+)"\])?\]$') - - def srs(self): - """ - Returns a GDAL SpatialReference object, if GDAL is installed. - """ - if HAS_GDAL: - # TODO: Is caching really necessary here? Is complexity worth it? - if hasattr(self, '_srs'): - # Returning a clone of the cached SpatialReference object. - return self._srs.clone() - else: - # Attempting to cache a SpatialReference object. - - # Trying to get from WKT first. - try: - self._srs = SpatialReference(self.wkt) - return self.srs - except Exception, msg: - pass - - try: - self._srs = SpatialReference(self.proj4text) - return self.srs - except Exception, msg: - pass - - raise Exception('Could not get OSR SpatialReference from WKT: %s\nError:\n%s' % (self.wkt, msg)) - else: - raise Exception('GDAL is not installed.') - srs = property(srs) - - def ellipsoid(self): - """ - Returns a tuple of the ellipsoid parameters: - (semimajor axis, semiminor axis, and inverse flattening). - """ - if HAS_GDAL: - return self.srs.ellipsoid - else: - m = self.spheroid_regex.match(self.wkt) - if m: return (float(m.group('major')), float(m.group('flattening'))) - else: return None - ellipsoid = property(ellipsoid) - - def name(self): - "Returns the projection name." - return self.srs.name - name = property(name) - - def spheroid(self): - "Returns the spheroid name for this spatial reference." - return self.srs['spheroid'] - spheroid = property(spheroid) - - def datum(self): - "Returns the datum for this spatial reference." - return self.srs['datum'] - datum = property(datum) - - def projected(self): - "Is this Spatial Reference projected?" - if HAS_GDAL: - return self.srs.projected - else: - return self.wkt.startswith('PROJCS') - projected = property(projected) - - def local(self): - "Is this Spatial Reference local?" - if HAS_GDAL: - return self.srs.local - else: - return self.wkt.startswith('LOCAL_CS') - local = property(local) - - def geographic(self): - "Is this Spatial Reference geographic?" - if HAS_GDAL: - return self.srs.geographic - else: - return self.wkt.startswith('GEOGCS') - geographic = property(geographic) - - def linear_name(self): - "Returns the linear units name." - if HAS_GDAL: - return self.srs.linear_name - elif self.geographic: - return None - else: - m = self.units_regex.match(self.wkt) - return m.group('unit_name') - linear_name = property(linear_name) - - def linear_units(self): - "Returns the linear units." - if HAS_GDAL: - return self.srs.linear_units - elif self.geographic: - return None - else: - m = self.units_regex.match(self.wkt) - return m.group('unit') - linear_units = property(linear_units) - - def angular_name(self): - "Returns the name of the angular units." - if HAS_GDAL: - return self.srs.angular_name - elif self.projected: - return None - else: - m = self.units_regex.match(self.wkt) - return m.group('unit_name') - angular_name = property(angular_name) - - def angular_units(self): - "Returns the angular units." - if HAS_GDAL: - return self.srs.angular_units - elif self.projected: - return None - else: - m = self.units_regex.match(self.wkt) - return m.group('unit') - angular_units = property(angular_units) - - def units(self): - "Returns a tuple of the units and the name." - if self.projected or self.local: - return (self.linear_units, self.linear_name) - elif self.geographic: - return (self.angular_units, self.angular_name) - else: - return (None, None) - units = property(units) - - def get_units(cls, wkt): - """ - Class method used by GeometryField on initialization to - retrive the units on the given WKT, without having to use - any of the database fields. - """ - if HAS_GDAL: - return SpatialReference(wkt).units - else: - m = cls.units_regex.match(wkt) - return m.group('unit'), m.group('unit_name') - get_units = classmethod(get_units) - - def get_spheroid(cls, wkt, string=True): - """ - Class method used by GeometryField on initialization to - retrieve the `SPHEROID[..]` parameters from the given WKT. - """ - if HAS_GDAL: - srs = SpatialReference(wkt) - sphere_params = srs.ellipsoid - sphere_name = srs['spheroid'] - else: - m = cls.spheroid_regex.match(wkt) - if m: - sphere_params = (float(m.group('major')), float(m.group('flattening'))) - sphere_name = m.group('name') - else: - return None - - if not string: - return sphere_name, sphere_params - else: - # `string` parameter used to place in format acceptable by PostGIS - if len(sphere_params) == 3: - radius, flattening = sphere_params[0], sphere_params[2] - else: - radius, flattening = sphere_params - return 'SPHEROID["%s",%s,%s]' % (sphere_name, radius, flattening) - get_spheroid = classmethod(get_spheroid) - - def __unicode__(self): - """ - Returns the string representation. If GDAL is installed, - it will be 'pretty' OGC WKT. - """ - try: - return unicode(self.srs) - except: - return unicode(self.wkt) - -# Django test suite on 2.3 platforms will choke on code inside this -# conditional. -if not PYTHON23: - try: - # try/except'ing the importation of SpatialBackend. Have to fail - # silently because this module may be inadvertently invoked by - # non-GeoDjango users (e.g., when the Django test suite executes - # the models.py of all contrib apps). - from django.contrib.gis.db.backend import SpatialBackend - if SpatialBackend.mysql: raise Exception - - # Exposing the SpatialRefSys and GeometryColumns models. - class SpatialRefSys(SpatialBackend.SpatialRefSys, SpatialRefSysMixin): - pass - GeometryColumns = SpatialBackend.GeometryColumns - except: - pass |