Introduce dynamic scope_path regexps
Instead of relying on scope_path's being "one slash deep", we should
instead allow for either:
1. scope_paths that have a pre-defined depth
2. scope_paths that can be arbitrarily deep
We achieve 1 by setting an entities scope_logic to another logic
module. We then recursively call getScopeDepth until we get to the
topmost entity (that is, an unscoped entity).
A little different is the solution to 2, since some entities can have
an arbitrarily deep scope (such as Documents), we need to have some
way of signaling this to getScopePattern. A clean solution is to
return None, rather than a number. If None is returned, the
SCOPE_PATH_ARG_PATTERN is returned as regexp instead, which will
match an arbitrarily deeply nested scope.
The solution for 2 requires that we return None somewhere in the
scope_logic chain, the most straight forward method to do so is to
override getScopeDepth anywhere such a scope is needed and make it
return None. A more elegant solution however, is to set the
scope_logic to that module in all entities that require it.
Patch by: Sverre Rabbelier
"""
This module houses ctypes interfaces for GDAL objects. The following GDAL
objects are supported:
CoordTransform: Used for coordinate transformations from one spatial
reference system to another.
Driver: Wraps an OGR data source driver.
DataSource: Wrapper for the OGR data source object, supports
OGR-supported data sources.
Envelope: A ctypes structure for bounding boxes (GDAL library
not required).
OGRGeometry: Layer for accessing OGR Geometry objects.
OGRGeomType: A class for representing the different OGR Geometry
types (GDAL library not required).
SpatialReference: Represents OSR Spatial Reference objects.
The GDAL library will be imported from the system path using the default
library name for the current OS. The default library path may be overridden
by setting `GDAL_LIBRARY_PATH` in your settings with the path to the GDAL C
library on your system.
GDAL links to a large number of external libraries that consume RAM when
loaded. Thus, it may desirable to disable GDAL on systems with limited
RAM resources -- this may be accomplished by setting `GDAL_LIBRARY_PATH`
to a non-existant file location (e.g., `GDAL_LIBRARY_PATH='/null/path'`;
setting to None/False/'' will not work as a string must be given).
"""
import sys
# Attempting to import objects that depend on the GDAL library. The
# HAS_GDAL flag will be set to True if the library is present on
# the system.
try:
from django.contrib.gis.gdal.driver import Driver
from django.contrib.gis.gdal.datasource import DataSource
from django.contrib.gis.gdal.libgdal import gdal_version, gdal_full_version, gdal_release_date
from django.contrib.gis.gdal.srs import SpatialReference, CoordTransform
from django.contrib.gis.gdal.geometries import OGRGeometry, GEOJSON
HAS_GDAL = True
except:
HAS_GDAL, GEOJSON = False, False
# The envelope, error, and geomtype modules do not actually require the
# GDAL library, but still nead at least Python 2.4 and ctypes.
PYTHON23 = sys.version_info[0] == 2 and sys.version_info[1] == 3
if not PYTHON23:
try:
from django.contrib.gis.gdal.envelope import Envelope
from django.contrib.gis.gdal.error import check_err, OGRException, OGRIndexError, SRSException
from django.contrib.gis.gdal.geomtype import OGRGeomType
except ImportError:
# No ctypes, but don't raise an exception.
pass