diff options
Diffstat (limited to 'apps/projects/shortcuts.py')
| -rw-r--r-- | apps/projects/shortcuts.py | 235 |
1 files changed, 0 insertions, 235 deletions
diff --git a/apps/projects/shortcuts.py b/apps/projects/shortcuts.py deleted file mode 100644 index d54410c..0000000 --- a/apps/projects/shortcuts.py +++ /dev/null @@ -1,235 +0,0 @@ -from django.contrib.gis.db.models.fields import GeometryField
-#from django.contrib.gis.gdal import Envelope
-from django.contrib.gis.geos import Polygon
-from django.utils import simplejson
-from django.http import HttpResponse
-#from django.db.models.fields.related import ManyRelatedManager
-
-# also need to check out:
-# http://code.google.com/p/dojango/source/browse/trunk/dojango/util/__init__.py#82
-
-
-# example usages:
-
-"""
-
-def a_shapes(request):
- ids = request.GET.get('ids').split(',')
- mimetype = 'text/plain' #'application/javascript; charset=utf8'
- pretty_print = True
- if ids:
- qs = WorldBorders.objects.filter(affiliates__in=ids).annotate(num_a=Count('affiliates')).filter(num_a__gt=0)
- else:
- qs = WorldBorders.objects.none()
- return render_to_geojson(qs,
- extra_attributes=['num_a','affiliates_set'],
- geom_attribute='point',
- included_fields=['id','name'],
- mimetype=mimetype,
- proj_transform=900913,
- pretty_print=pretty_print
- )
-
-def responses(qs,type_='countries',pretty_print=True,mimetype='text/plain'):
- if type_ == 'locations':
- qs = qs.geolocations()
- return render_to_geojson(qs,
- excluded_fields=['json'],
- geom_field='point',
- proj_transform=900913,
- mimetype=mimetype,
- pretty_print=pretty_print
- )
- elif type_ == 'affiliates':
- qs = qs.exclude(geokeywords='').attach_locations()
- return render_to_geojson(qs,
- included_fields=['id','_geokeywords_cache'],
- geom_attribute='point',
- extra_attributes=['name'],
- proj_transform=900913,
- mimetype=mimetype,
- pretty_print=pretty_print
- )
- elif type_ == 'countries':
- qs2 = W.objects.filter(affiliates__in=qs).annotate(num_a=Count('affiliates')).filter(num_a__gt=0)
- return render_to_geojson(qs2,
- extra_attributes=['num_a'],
- #geom_attribute='point',
- mimetype=mimetype,
- pretty_print=pretty_print
- )
- else:# type_ == 'countries' or type is None:
- if len(qs) > 10:
- # this is a limit, weird huh?
- # requires another all() otherwise it
- # returns a list!
- qs = qs.all()[:10]
- return render_to_geojson(qs,
- included_fields=['id','_geokeywords_cache'],
- geom_attribute='countries.unionagg',
- extra_attributes=['name'],
- mimetype=mimetype,
- pretty_print=pretty_print
- )
-"""
-
-
-
-def render_to_geojson(query_set, geom_field=None, geom_attribute=None, extra_attributes=[],mimetype='text/plain', pretty_print=False, excluded_fields=[],included_fields=[],proj_transform=None):
- '''
-
- Shortcut to render a GeoJson FeatureCollection from a Django QuerySet.
- Currently computes a bbox and adds a crs member as a sr.org link
-
- '''
- excluded_fields.append('_state')
- collection = {}
- if hasattr(query_set,'_meta'): # its a model instance
- fields = query_set._meta.fields
- query_set = [query_set]
- else:
- fields = query_set.model._meta.fields
-
- if geom_attribute:
- geometry_name = geom_attribute
- geo_field = None
- if '.' in geom_attribute:
- prop, meth = geom_attribute.split('.')
- if len(query_set):
- p = getattr(query_set[0],prop)
- geo_field = getattr(p,meth)
- if callable(geo_field):
- geo_field = geo_field()
- else:
- if len(query_set):
- geo_field = getattr(query_set[0],geom_attribute)
- if callable(geo_field):
- geo_field = geo_field()
- if not geo_field:
- srid = 4326
- else:
- srid = geo_field.srid
-
- else:
- geo_fields = [f for f in fields if isinstance(f, GeometryField)]
-
- #attempt to assign geom_field that was passed in
- if geom_field:
- #import pdb;pdb.set_trace()
- geo_fieldnames = [x.name for x in geo_fields]
- try:
- geo_field = geo_fields[geo_fieldnames.index(geom_field)]
- except:
- raise Exception('%s is not a valid geometry on this model' % geom_field)
- else:
- if not len(geo_fields):
- raise Exception('There appears to be no valid geometry on this model')
- geo_field = geo_fields[0] # no support yet for multiple geometry fields
-
-
- #remove other geom fields from showing up in attributes
- if len(geo_fields) > 1:
- for field in geo_fields:
- if field.name not in excluded_fields:
- excluded_fields.append(field.name)
-
- geometry_name = geo_field.name
-
-
- srid = geo_field.srid
-
- if proj_transform:
- to_srid = proj_transform
- else:
- to_srid = srid
- # Gather the projection information
- crs = {}
- crs['type'] = "link"
- crs_properties = {}
- crs_properties['href'] = 'http://spatialreference.org/ref/epsg/%s/' % to_srid
- crs_properties['type'] = 'proj4'
- crs['properties'] = crs_properties
- collection['crs'] = crs
- collection['srid'] = to_srid
-
- # Build list of features
- features = []
- if query_set.distinct():
- for item in query_set:
- feat = {}
- feat['type'] = 'Feature'
- if included_fields:
- d = {}
- for f in included_fields:
- if hasattr(item,f):
- d[f] = getattr(item,f)
- else:
- d = item.__dict__.copy()
- for field in excluded_fields:
- if field in d.keys():
- d.pop(field)
- if geometry_name in d:
- d.pop(geometry_name)
-
- for attr in extra_attributes:
- a = getattr(item,attr)
- # crappy way of trying to figure out it this is a
- # m2m, aka 'ManyRelatedManager'
- if hasattr(a,'values_list'):
- a = list(a.values_list('id',flat=True))
- if callable(a):
- d[attr] = a()
- else:
- d[attr] = a
- if '.' in geometry_name:
- prop, meth = geometry_name.split('.')
- a = getattr(item,prop)
- g = getattr(a,meth)
- if callable(g):
- g = g()
- else:
- g = getattr(item,geometry_name)
- if g:
- if proj_transform:
- g.transform(proj_transform)
- feat['geometry'] = simplejson.loads(g.geojson)
- feat['properties'] = d
- features.append(feat)
- else:
- pass #features.append({'type':'Feature','geometry': {},'properties':{}})
-
- # Label as FeatureCollection and add Features
- collection['type'] = "FeatureCollection"
- collection['features'] = features
-
- # Attach extent of all features
- if query_set:
- ex = None
- query_set.query.distinct = False
- if hasattr(query_set,'agg_extent'):
- ex = [x for x in query_set.agg_extent.tuple]
- elif '.' in geometry_name:
- prop, meth = geometry_name.split('.')
- a = getattr(item,prop)
- if a:
- ex = [x for x in a.extent()]
- else:
- # make sure qs does not have .distinct() in it...
- ex = [x for x in query_set.extent()]
- if ex:
- if proj_transform:
- poly = Polygon.from_bbox(ex)
- poly.srid = srid
- poly.transform(proj_transform)
- ex = poly.extent
- collection['bbox'] = ex
-
- # Return response
- response = HttpResponse()
- if pretty_print:
- response.write('%s' % simplejson.dumps(collection, indent=1))
- else:
- response.write('%s' % simplejson.dumps(collection))
- response['Content-length'] = str(len(response.content))
- response['Content-Type'] = mimetype
- return response
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