author | Sverre Rabbelier <srabbelier@gmail.com> |
Sun, 07 Dec 2008 17:02:10 +0000 | |
changeset 705 | 0ab17e14df95 |
parent 323 | ff1a9aa48cfd |
permissions | -rw-r--r-- |
323
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Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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1 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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|
2 |
Imports the SpatialRefSys and GeometryColumns models dependent on the |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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|
3 |
spatial database backend. |
ff1a9aa48cfd
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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4 |
""" |
ff1a9aa48cfd
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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5 |
import re |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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6 |
from django.conf import settings |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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7 |
|
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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8 |
# Checking for the presence of GDAL (needed for the SpatialReference object) |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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9 |
from django.contrib.gis.gdal import HAS_GDAL, PYTHON23 |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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10 |
if HAS_GDAL: |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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11 |
from django.contrib.gis.gdal import SpatialReference |
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parents:
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12 |
|
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parents:
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13 |
class SpatialRefSysMixin(object): |
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parents:
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14 |
""" |
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parents:
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15 |
The SpatialRefSysMixin is a class used by the database-dependent |
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Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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16 |
SpatialRefSys objects to reduce redundnant code. |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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17 |
""" |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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18 |
|
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parents:
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19 |
# For pulling out the spheroid from the spatial reference string. This |
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parents:
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20 |
# regular expression is used only if the user does not have GDAL installed. |
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parents:
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21 |
# TODO: Flattening not used in all ellipsoids, could also be a minor axis, or 'b' |
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parents:
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22 |
# parameter. |
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23 |
spheroid_regex = re.compile(r'.+SPHEROID\[\"(?P<name>.+)\",(?P<major>\d+(\.\d+)?),(?P<flattening>\d{3}\.\d+),') |
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24 |
|
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25 |
# For pulling out the units on platforms w/o GDAL installed. |
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parents:
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26 |
# TODO: Figure out how to pull out angular units of projected coordinate system and |
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parents:
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27 |
# fix for LOCAL_CS types. GDAL should be highly recommended for performing |
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parents:
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28 |
# distance queries. |
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29 |
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+)"\])?\]$') |
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30 |
|
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def srs(self): |
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32 |
""" |
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parents:
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33 |
Returns a GDAL SpatialReference object, if GDAL is installed. |
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parents:
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34 |
""" |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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35 |
if HAS_GDAL: |
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parents:
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36 |
if hasattr(self, '_srs'): |
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37 |
# Returning a clone of the cached SpatialReference object. |
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return self._srs.clone() |
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39 |
else: |
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parents:
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40 |
# Attempting to cache a SpatialReference object. |
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parents:
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41 |
|
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parents:
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42 |
# Trying to get from WKT first. |
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parents:
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43 |
try: |
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parents:
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44 |
self._srs = SpatialReference(self.wkt) |
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45 |
return self.srs |
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46 |
except Exception, msg: |
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47 |
pass |
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48 |
|
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49 |
raise Exception('Could not get OSR SpatialReference from WKT: %s\nError:\n%s' % (self.wkt, msg)) |
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50 |
else: |
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51 |
raise Exception('GDAL is not installed.') |
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52 |
srs = property(srs) |
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|
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54 |
def ellipsoid(self): |
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55 |
""" |
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parents:
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56 |
Returns a tuple of the ellipsoid parameters: |
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parents:
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57 |
(semimajor axis, semiminor axis, and inverse flattening). |
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58 |
""" |
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parents:
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59 |
if HAS_GDAL: |
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60 |
return self.srs.ellipsoid |
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else: |
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62 |
m = self.spheroid_regex.match(self.wkt) |
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if m: return (float(m.group('major')), float(m.group('flattening'))) |
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64 |
else: return None |
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65 |
ellipsoid = property(ellipsoid) |
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66 |
|
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67 |
def name(self): |
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"Returns the projection name." |
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69 |
return self.srs.name |
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name = property(name) |
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parents:
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71 |
|
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72 |
def spheroid(self): |
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"Returns the spheroid name for this spatial reference." |
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74 |
return self.srs['spheroid'] |
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75 |
spheroid = property(spheroid) |
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76 |
|
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77 |
def datum(self): |
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parents:
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78 |
"Returns the datum for this spatial reference." |
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79 |
return self.srs['datum'] |
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80 |
datum = property(datum) |
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|
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82 |
def projected(self): |
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83 |
"Is this Spatial Reference projected?" |
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parents:
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84 |
if HAS_GDAL: |
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85 |
return self.srs.projected |
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86 |
else: |
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87 |
return self.wkt.startswith('PROJCS') |
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88 |
projected = property(projected) |
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parents:
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89 |
|
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90 |
def local(self): |
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parents:
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91 |
"Is this Spatial Reference local?" |
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parents:
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92 |
if HAS_GDAL: |
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93 |
return self.srs.local |
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94 |
else: |
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parents:
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95 |
return self.wkt.startswith('LOCAL_CS') |
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parents:
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96 |
local = property(local) |
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parents:
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97 |
|
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98 |
def geographic(self): |
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parents:
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99 |
"Is this Spatial Reference geographic?" |
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Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
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100 |
if HAS_GDAL: |
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parents:
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101 |
return self.srs.geographic |
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102 |
else: |
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parents:
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103 |
return self.wkt.startswith('GEOGCS') |
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parents:
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104 |
geographic = property(geographic) |
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parents:
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105 |
|
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parents:
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106 |
def linear_name(self): |
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parents:
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107 |
"Returns the linear units name." |
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108 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
109 |
return self.srs.linear_name |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
110 |
elif self.geographic: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
111 |
return None |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
112 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
113 |
m = self.units_regex.match(self.wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
114 |
return m.group('unit_name') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
115 |
linear_name = property(linear_name) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
116 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
117 |
def linear_units(self): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
118 |
"Returns the linear units." |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
119 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
120 |
return self.srs.linear_units |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
121 |
elif self.geographic: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
122 |
return None |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
123 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
124 |
m = self.units_regex.match(self.wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
125 |
return m.group('unit') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
126 |
linear_units = property(linear_units) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
127 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
128 |
def angular_name(self): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
129 |
"Returns the name of the angular units." |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
130 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
131 |
return self.srs.angular_name |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
132 |
elif self.projected: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
133 |
return None |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
134 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
135 |
m = self.units_regex.match(self.wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
136 |
return m.group('unit_name') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
137 |
angular_name = property(angular_name) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
138 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
139 |
def angular_units(self): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
140 |
"Returns the angular units." |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
141 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
142 |
return self.srs.angular_units |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
143 |
elif self.projected: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
144 |
return None |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
145 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
146 |
m = self.units_regex.match(self.wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
147 |
return m.group('unit') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
148 |
angular_units = property(angular_units) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
149 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
150 |
def units(self): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
151 |
"Returns a tuple of the units and the name." |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
152 |
if self.projected or self.local: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
153 |
return (self.linear_units, self.linear_name) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
154 |
elif self.geographic: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
155 |
return (self.angular_units, self.angular_name) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
156 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
157 |
return (None, None) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
158 |
units = property(units) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
159 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
160 |
def get_units(cls, wkt): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
161 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
162 |
Class method used by GeometryField on initialization to |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
163 |
retrive the units on the given WKT, without having to use |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
164 |
any of the database fields. |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
165 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
166 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
167 |
return SpatialReference(wkt).units |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
168 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
169 |
m = cls.units_regex.match(wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
170 |
return m.group('unit'), m.group('unit_name') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
171 |
get_units = classmethod(get_units) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
172 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
173 |
def get_spheroid(cls, wkt, string=True): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
174 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
175 |
Class method used by GeometryField on initialization to |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
176 |
retrieve the `SPHEROID[..]` parameters from the given WKT. |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
177 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
178 |
if HAS_GDAL: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
179 |
srs = SpatialReference(wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
180 |
sphere_params = srs.ellipsoid |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
181 |
sphere_name = srs['spheroid'] |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
182 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
183 |
m = cls.spheroid_regex.match(wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
184 |
if m: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
185 |
sphere_params = (float(m.group('major')), float(m.group('flattening'))) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
186 |
sphere_name = m.group('name') |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
187 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
188 |
return None |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
189 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
190 |
if not string: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
191 |
return sphere_name, sphere_params |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
192 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
193 |
# `string` parameter used to place in format acceptable by PostGIS |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
194 |
if len(sphere_params) == 3: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
195 |
radius, flattening = sphere_params[0], sphere_params[2] |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
196 |
else: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
197 |
radius, flattening = sphere_params |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
198 |
return 'SPHEROID["%s",%s,%s]' % (sphere_name, radius, flattening) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
199 |
get_spheroid = classmethod(get_spheroid) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
200 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
201 |
def __unicode__(self): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
202 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
203 |
Returns the string representation. If GDAL is installed, |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
204 |
it will be 'pretty' OGC WKT. |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
205 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
206 |
try: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
207 |
return unicode(self.srs) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
208 |
except: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
209 |
return unicode(self.wkt) |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
210 |
|
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
211 |
# The SpatialRefSys and GeometryColumns models |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
212 |
_srid_info = True |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
213 |
if not PYTHON23 and settings.DATABASE_ENGINE == 'postgresql_psycopg2': |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
214 |
# Because the PostGIS version is checked when initializing the spatial |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
215 |
# backend a `ProgrammingError` will be raised if the PostGIS tables |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
216 |
# and functions are not installed. We catch here so it won't be raised when |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
217 |
# running the Django test suite. `ImportError` is also possible if no ctypes. |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
218 |
try: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff
changeset
|
219 |
from django.contrib.gis.db.backend.postgis.models import GeometryColumns, SpatialRefSys |
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220 |
except: |
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_srid_info = False |
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elif not PYTHON23 and settings.DATABASE_ENGINE == 'oracle': |
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# Same thing as above, except the GEOS library is attempted to be loaded for |
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224 |
# `BaseSpatialBackend`, and an exception will be raised during the |
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# Django test suite if it doesn't exist. |
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226 |
try: |
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from django.contrib.gis.db.backend.oracle.models import GeometryColumns, SpatialRefSys |
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228 |
except: |
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229 |
_srid_info = False |
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230 |
else: |
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231 |
_srid_info = False |
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232 |
|
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233 |
if _srid_info: |
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234 |
def get_srid_info(srid): |
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235 |
""" |
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236 |
Returns the units, unit name, and spheroid WKT associated with the |
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237 |
given SRID from the `spatial_ref_sys` (or equivalent) spatial database |
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238 |
table. We use a database cursor to execute the query because this |
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239 |
function is used when it is not possible to use the ORM (for example, |
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240 |
during field initialization). |
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241 |
""" |
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242 |
# SRID=-1 is a common convention for indicating the geometry has no |
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243 |
# spatial reference information associated with it. Thus, we will |
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244 |
# return all None values without raising an exception. |
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245 |
if srid == -1: return None, None, None |
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246 |
|
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247 |
# Getting the spatial reference WKT associated with the SRID from the |
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248 |
# `spatial_ref_sys` (or equivalent) spatial database table. This query |
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249 |
# cannot be executed using the ORM because this information is needed |
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250 |
# when the ORM cannot be used (e.g., during the initialization of |
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251 |
# `GeometryField`). |
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252 |
from django.db import connection |
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253 |
cur = connection.cursor() |
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254 |
qn = connection.ops.quote_name |
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255 |
stmt = 'SELECT %(table)s.%(wkt_col)s FROM %(table)s WHERE (%(table)s.%(srid_col)s = %(srid)s)' |
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256 |
stmt = stmt % {'table' : qn(SpatialRefSys._meta.db_table), |
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257 |
'wkt_col' : qn(SpatialRefSys.wkt_col()), |
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258 |
'srid_col' : qn('srid'), |
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259 |
'srid' : srid, |
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260 |
} |
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|
261 |
cur.execute(stmt) |
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parents:
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|
262 |
|
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|
263 |
# Fetching the WKT from the cursor; if the query failed raise an Exception. |
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parents:
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|
264 |
fetched = cur.fetchone() |
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|
265 |
if not fetched: |
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|
266 |
raise ValueError('Failed to find spatial reference entry in "%s" corresponding to SRID=%s.' % |
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Load ../vendor/django into trunk/app/django.
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|
267 |
(SpatialRefSys._meta.db_table, srid)) |
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|
268 |
srs_wkt = fetched[0] |
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parents:
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|
269 |
|
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|
270 |
# Getting metadata associated with the spatial reference system identifier. |
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parents:
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|
271 |
# Specifically, getting the unit information and spheroid information |
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|
272 |
# (both required for distance queries). |
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|
273 |
unit, unit_name = SpatialRefSys.get_units(srs_wkt) |
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|
274 |
spheroid = SpatialRefSys.get_spheroid(srs_wkt) |
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|
275 |
return unit, unit_name, spheroid |
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parents:
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|
276 |
else: |
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parents:
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|
277 |
def get_srid_info(srid): |
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parents:
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|
278 |
""" |
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parents:
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|
279 |
Dummy routine for the backends that do not have the OGC required |
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parents:
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|
280 |
spatial metadata tables (like MySQL). |
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parents:
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|
281 |
""" |
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parents:
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|
282 |
return None, None, None |
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parents:
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|
283 |