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Code Issues 32 Releases Wiki Activity

gis: SpatialRefSys model now uses HAS_GDAL flag, no longer uses _cache_osr(), and improved docstrings.

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git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@6427 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Justin Bronn 2007-09-27 16:42:20 +00:00
parent e835868621
commit cfb807a1fb
3 changed files with 50 additions and 57 deletions
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2
django/contrib/gis/db/backend/postgis/__init__.py
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@ -1,5 +1,5 @@
""" """
The PostGIS spatial database backend module. The PostGIS spatial database backend module.
""" """
from django.contrib.gis.db.backend.postgis.query import \ from django.contrib.gis.db.backend.postgis.query import \
get_geo_where_clause, geo_quotename, \ get_geo_where_clause, geo_quotename, \

2
django/contrib/gis/db/backend/postgis/creation.py
View File

@ -163,7 +163,7 @@ def get_spatial_db(test=False):
return settings.DATABASE_NAME return settings.DATABASE_NAME
def load_postgis_sql(db_name, verbosity=1): def load_postgis_sql(db_name, verbosity=1):
"""" """
This routine loads up the PostGIS SQL files lwpostgis.sql and This routine loads up the PostGIS SQL files lwpostgis.sql and
spatial_ref_sys.sql. spatial_ref_sys.sql.
""" """

103
django/contrib/gis/models.py
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@ -1,16 +1,13 @@
"""
Models for the PostGIS/OGC database tables.
"""
import re import re
from django.db import models from django.db import models
# Checking for the presence of GDAL # Checking for the presence of GDAL (needed for the SpatialReference object)
try: from django.contrib.gis.gdal import HAS_GDAL
if HAS_GDAL:
from django.contrib.gis.gdal import SpatialReference from django.contrib.gis.gdal import SpatialReference
HAS_OSR = True
except ImportError:
HAS_OSR = False
"""
Models for the PostGIS/OGC database tables.
"""
# For pulling out the spheroid from the spatial reference string. This # For pulling out the spheroid from the spatial reference string. This
# regular expression is used only if the user does not have GDAL installed. # regular expression is used only if the user does not have GDAL installed.
@ -33,7 +30,9 @@ class GeometryColumns(models.Model):
db_table = 'geometry_columns' db_table = 'geometry_columns'
def __str__(self): def __str__(self):
return "%s.%s - %dD %s field (SRID: %d)" % (self.f_table_name, self.f_geometry_column, self.coord_dimension, self.type, self.srid) return "%s.%s - %dD %s field (SRID: %d)" % \
(self.f_table_name, self.f_geometry_column,
self.coord_dimension, self.type, self.srid)
# This is the global 'spatial_ref_sys' table from PostGIS. # This is the global 'spatial_ref_sys' table from PostGIS.
# See PostGIS Documentation at Ch. 4.2.1 # See PostGIS Documentation at Ch. 4.2.1
@ -47,41 +46,44 @@ class SpatialRefSys(models.Model):
class Meta: class Meta:
db_table = 'spatial_ref_sys' db_table = 'spatial_ref_sys'
def _cache_osr(self): @property
"Caches a GDAL OSR SpatialReference object for this SpatialRefSys model." def srs(self):
if HAS_OSR: """
if not hasattr(self, '_srs'): Returns a GDAL SpatialReference object, if GDAL is installed.
"""
if HAS_GDAL:
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 # Trying to get from WKT first
try: try:
self._srs = SpatialReference(self.srtext, 'wkt') self._srs = SpatialReference(self.srtext, 'wkt')
return return self._srs.clone()
except Exception, msg: except Exception, msg1:
pass pass
# Trying the proj4 text next # Trying the proj4 text next
try: try:
self._srs = SpatialReference(self.proj4text, 'proj4') self._srs = SpatialReference(self.proj4text, 'proj4')
return return self._srs.clone()
except Exception, msg: except Exception, msg2:
pass pass
raise Exception, 'Could not get a OSR Spatial Reference: %s' % msg raise Exception, 'Could not get an OSR Spatial Reference:\n\tWKT error: %s\n\tPROJ.4 error: %s' % (msg1, msg2)
else: else:
raise Exception, 'GDAL is not installed!' raise Exception, 'GDAL is not installed!'
@property
def srs(self):
"Returns the SpatialReference equivalent of this model."
self._cache_osr()
return self._srs.clone()
@property @property
def ellipsoid(self): def ellipsoid(self):
"""Returns a tuple of the ellipsoid parameters: """
(semimajor axis, semiminor axis, and inverse flattening).""" Returns a tuple of the ellipsoid parameters:
if HAS_OSR: (semimajor axis, semiminor axis, and inverse flattening).
self._cache_osr() """
return self._srs.ellipsoid if HAS_GDAL:
return self.srs.ellipsoid
else: else:
m = spheroid_regex.match(self.srtext) m = spheroid_regex.match(self.srtext)
if m: return (float(m.group('major')), float(m.group('flattening'))) if m: return (float(m.group('major')), float(m.group('flattening')))
@ -90,66 +92,57 @@ class SpatialRefSys(models.Model):
@property @property
def name(self): def name(self):
"Returns the projection name." "Returns the projection name."
self._cache_osr() return self.srs.name
return self._srs.name
@property @property
def spheroid(self): def spheroid(self):
"Returns the spheroid for this spatial reference." "Returns the spheroid for this spatial reference."
self._cache_osr() return self.srs['spheroid']
return self._srs['spheroid']
@property @property
def datum(self): def datum(self):
"Returns the datum for this spatial reference." "Returns the datum for this spatial reference."
self._cache_osr() return self.srs['datum']
return self._srs['datum']
@property @property
def projected(self): def projected(self):
"Is this Spatial Reference projected?" "Is this Spatial Reference projected?"
self._cache_osr() return self.srs.projected
return self._srs.projected
@property @property
def local(self): def local(self):
"Is this Spatial Reference local?" "Is this Spatial Reference local?"
self._cache_osr() return self.srs.local
return self._srs.local
@property @property
def geographic(self): def geographic(self):
"Is this Spatial Reference geographic?" "Is this Spatial Reference geographic?"
self._cache_osr() return self.srs.geographic
return self._srs.geographic
@property @property
def linear_name(self): def linear_name(self):
"Returns the linear units name." "Returns the linear units name."
self._cache_osr() return self.srs.linear_name
return self._srs.linear_name
@property @property
def linear_units(self): def linear_units(self):
"Returns the linear units." "Returns the linear units."
self._cache_osr() return self.srs.linear_units
return self._srs.linear_units
@property @property
def angular_units(self): def angular_units(self):
"Returns the angular units." "Returns the angular units."
self._cache_osr() return self.srs.angular_units
return self._srs.angular_units
@property @property
def angular_name(self): def angular_name(self):
"Returns the name of the angular units." "Returns the name of the angular units."
self._cache_osr() return self.srs.angular_name
return self._srs.angular_name
def __str__(self): def __str__(self):
"Returns the string representation. If GDAL is installed, it will be 'pretty' OGC WKT." """
if HAS_OSR: Returns the string representation. If GDAL is installed,
self._cache_osr() it will be 'pretty' OGC WKT.
if hasattr(self, '_srs'): return str(self._srs) """
return "%d:%s " % (self.srid, self.auth_name) if HAS_GDAL: return str(self.srs)
else: return "%d:%s " % (self.srid, self.auth_name)