import os, sys
from optparse import make_option
from django.contrib.gis import gdal
from django.contrib.gis.management.base import ArgsCommand,CommandError
def layer_option(option, opt, value, parser):
"""
Callback for `make_option` for the `ogrinspect` `layer_key`
keyword option which may be an integer or a string.
"""
try:
dest = int(value)
except ValueError:
dest = value
setattr(parser.values, option.dest, dest)
def list_option(option, opt, value, parser):
"""
Callback for `make_option` for `ogrinspect` keywords that require
a string list. If the string is 'True'/'true' then the option
value will be a boolean instead.
"""
if value.lower() == 'true':
dest = True
else:
dest = [s for s in value.split(',')]
setattr(parser.values, option.dest, dest)
class Command(ArgsCommand):
help = ('Inspects the given OGR-compatible data source (e.g., a shapefile) and outputs\n'
'a GeoDjango model with the given model name. For example:\n'
' ./manage.py ogrinspect zipcode.shp Zipcode')
args = '[data_source] [model_name]'
option_list = ArgsCommand.option_list + (
make_option('--blank', dest='blank', type='string', action='callback',
callback=list_option, default=False,
help='Use a comma separated list of OGR field names to add '
'the `blank=True` option to the field definition. Set with'
'`true` to apply to all applicable fields.'),
make_option('--decimal', dest='decimal', type='string', action='callback',
callback=list_option, default=False,
help='Use a comma separated list of OGR float fields to '
'generate `DecimalField` instead of the default '
'`FloatField`. Set to `true` to apply to all OGR float fields.'),
make_option('--geom-name', dest='geom_name', type='string', default='geom',
help='Specifies the model name for the Geometry Field '
'(defaults to `geom`)'),
make_option('--layer', dest='layer_key', type='string', action='callback',
callback=layer_option, default=0,
help='The key for specifying which layer in the OGR data '
'source to use. Defaults to 0 (the first layer). May be '
'an integer or a string identifier for the layer.'),
make_option('--multi-geom', action='store_true', dest='multi_geom', default=False,
help='Treat the geometry in the data source as a geometry collection.'),
make_option('--name-field', dest='name_field',
help='Specifies a field name to return for the `__unicode__` function.'),
make_option('--no-imports', action='store_false', dest='imports', default=True,
help='Do not include `from django.contrib.gis.db import models` '
'statement.'),
make_option('--null', dest='null', type='string', action='callback',
callback=list_option, default=False,
help='Use a comma separated list of OGR field names to add '
'the `null=True` option to the field definition. Set with'
'`true` to apply to all applicable fields.'),
make_option('--srid', dest='srid',
help='The SRID to use for the Geometry Field. If it can be '
'determined, the SRID of the data source is used.'),
make_option('--mapping', action='store_true', dest='mapping',
help='Generate mapping dictionary for use with `LayerMapping`.')
)
requires_model_validation = False
def handle_args(self, *args, **options):
try:
data_source, model_name = args
except ValueError:
raise CommandError('Invalid arguments, must provide: %s' % self.args)
if not gdal.HAS_GDAL:
raise CommandError('GDAL is required to inspect geospatial data sources.')
# TODO: Support non file-based OGR datasources.
if not os.path.isfile(data_source):
raise CommandError('The given data source cannot be found: "%s"' % data_source)
# Removing options with `None` values.
options = dict([(k, v) for k, v in options.items() if not v is None])
# Getting the OGR DataSource from the string parameter.
try:
ds = gdal.DataSource(data_source)
except gdal.OGRException, msg:
raise CommandError(msg)
# Whether the user wants to generate the LayerMapping dictionary as well.
show_mapping = options.pop('mapping', False)
# Popping the verbosity global option, as it's not accepted by `_ogrinspect`.
verbosity = options.pop('verbosity', False)
# Returning the output of ogrinspect with the given arguments
# and options.
from django.contrib.gis.utils.ogrinspect import _ogrinspect,mapping
output = [s for s in _ogrinspect(ds, model_name, **options)]
if show_mapping:
# Constructing the keyword arguments for `mapping`, and
# calling it on the data source.
kwargs = {'geom_name' : options['geom_name'],
'layer_key' : options['layer_key'],
'multi_geom' : options['multi_geom'],
}
mapping_dict = mapping(ds, **kwargs)
# This extra legwork is so that the dictionary definition comes
# out in the same order as the fields in the model definition.
rev_mapping = dict([(v, k) for k, v in mapping_dict.items()])
output.extend(['', '# Auto-generated `LayerMapping` dictionary for %s model' % model_name,
'%s_mapping = {' % model_name.lower()])
output.extend([" '%s' : '%s'," % (rev_mapping[ogr_fld], ogr_fld) for ogr_fld in ds[options['layer_key']].fields])
output.extend([" '%s' : '%s'," % (options['geom_name'], mapping_dict[options['geom_name']]), '}'])
return '\n'.join(output)
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