Source Code for Module madrona.studyregion.management.commands.create_study_region

 1  from django.core.management.base import BaseCommand, AppCommand 
 2  from optparse import make_option 
 3  from django.contrib.gis.gdal import DataSource 
 4  from django.contrib.gis.geos import GEOSGeometry  
 5  from django.contrib.gis import geos 
 6  from django.conf import settings 
 7  from madrona.studyregion.models import StudyRegion 
 8   
 9 -class Command(BaseCommand): 
10      option_list = AppCommand.option_list + ( 
11          make_option('--name', action='store', dest='region_name', default=False, 
12              help='Give a name to the study region, otherwise the name attribute from the shapefile will be used.'), 
13      ) 
14      help = "Creates a new study region from a shapefile containing a single multigeometry" 
15      args = '[input shapefile or wkt string]' 
16   
17 -    def handle_ogr(self, inshape, name): 
18          ds = DataSource(inshape) 
19          layer = ds[0]  # assume first layer 
20          feature = layer[0]  #assume first feature 
21          if not name: 
22              try: 
23                  name = feature.name 
24              except: 
25                  raise Exception("No `name` field or --name provided!") 
26   
27          g1 = feature.geom.geos 
28          srid = g1.srid 
29          if not srid: 
30              # See if we can assume latlon 
31              missing_srid = True 
32              ext = list(g1.extent) 
33              latlonmax = [180,90] * 2 
34              latlonmin = [x * -1 for x in latlonmax] 
35              overs = [a for a,b in zip(ext, latlonmax) if a > b] 
36              unders = [a for a,b in zip(ext, latlonmin) if a < b] 
37              if len(overs) == len(unders) == 0: 
38                  srid = 4326 
39                  g1.srid = 4326 
40              else: 
41                  raise Exception("Unknown SRID. Try ewkt format; `SRID=4326;POLYGON((.....))`") 
42          if g1 and isinstance(g1, geos.Polygon): 
43              g1 = geos.MultiPolygon(g1) 
44              g1.srid = srid 
45          g1.transform(settings.GEOMETRY_DB_SRID) 
46   
47          region = StudyRegion.objects.create(geometry=g1, name=name, active=True) 
48          region.save() 
49   
50          print "Study region created: %s, primary key = %s" % (region.name, region.pk) 
51   
52 -    def handle_wkt(self, wkt, name): 
53          g1 = GEOSGeometry(wkt) 
54          srid = g1.srid 
55          if not srid: 
56              raise Exception("Unknown SRID. Try ewkt format; `SRID=4326;POLYGON((.....))`") 
57          if g1 and isinstance(g1, geos.Polygon): 
58              g1 = geos.MultiPolygon(g1) 
59              g1.srid = srid 
60   
61          if not name: 
62              raise Exception("No --name provided!") 
63   
64          g1.transform(settings.GEOMETRY_DB_SRID) 
65          region = StudyRegion.objects.create(geometry=g1, name=name, active=True) 
66          region.save() 
67   
68          print "Study region created: %s, primary key = %s" % (region.name, region.pk) 
69   
70 -    def handle(self, inshape, *args, **options): 
71          """ 
72          `inshape` can be a wkt string or shapefile path 
73          """ 
74          htype = '' 
75          name = options.get('region_name') 
76          try: 
77              ds = DataSource(inshape) 
78              htype = 'ogr' 
79          except: 
80              try: 
81                  g1 = GEOSGeometry(inshape) 
82                  htype = 'wkt' 
83              except: 
84                  pass 
85   
86          if htype == 'ogr': 
87              self.handle_ogr(inshape, name) 
88          elif htype == 'wkt': 
89              self.handle_wkt(inshape, name) 
90          else: 
91              raise Exception("Your input shape is not recognized as a valid datasource or geometry string") 
92