django1/django/contrib/gis/management/commands/ogrinspect.py

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import argparse
import inspect
from django.contrib.gis import gdal
from django.core.management.base import BaseCommand, CommandError
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class LayerOptionAction(argparse.Action):
"""
Custom argparse action for the `ogrinspect` `layer_key` keyword option
which may be an integer or a string.
"""
def __call__(self, parser, namespace, value, option_string=None):
try:
setattr(namespace, self.dest, int(value))
except ValueError:
setattr(namespace, self.dest, value)
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class ListOptionAction(argparse.Action):
"""
Custom argparse action for `ogrinspect` keywords that require
a string list. If the string is 'True'/'true' then the option
value will be a boolean instead.
"""
def __call__(self, parser, namespace, value, option_string=None):
if value.lower() == 'true':
setattr(namespace, self.dest, True)
else:
setattr(namespace, self.dest, value.split(','))
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class Command(BaseCommand):
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')
requires_system_checks = False
def add_arguments(self, parser):
parser.add_argument('data_source', help='Path to the data source.')
parser.add_argument('model_name', help='Name of the model to create.')
parser.add_argument('--blank', dest='blank',
action=ListOptionAction, default=False,
help='Use a comma separated list of OGR field names to add '
'the `blank=True` option to the field definition. Set to `true` '
'to apply to all applicable fields.')
parser.add_argument('--decimal', dest='decimal',
action=ListOptionAction, 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.')
parser.add_argument('--geom-name', dest='geom_name', default='geom',
help='Specifies the model name for the Geometry Field '
'(defaults to `geom`)')
parser.add_argument('--layer', dest='layer_key',
action=LayerOptionAction, 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.')
parser.add_argument('--multi-geom', action='store_true',
dest='multi_geom', default=False,
help='Treat the geometry in the data source as a geometry collection.')
parser.add_argument('--name-field', dest='name_field',
help='Specifies a field name to return for the `__unicode__`/`__str__` function.')
parser.add_argument('--no-imports', action='store_false', dest='imports', default=True,
help='Do not include `from django.contrib.gis.db import models` statement.')
parser.add_argument('--null', dest='null', action=ListOptionAction, default=False,
help='Use a comma separated list of OGR field names to add '
'the `null=True` option to the field definition. Set to `true` '
'to apply to all applicable fields.')
parser.add_argument('--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.')
parser.add_argument('--mapping', action='store_true', dest='mapping',
help='Generate mapping dictionary for use with `LayerMapping`.')
def handle(self, *args, **options):
data_source, model_name = options.pop('data_source'), options.pop('model_name')
if not gdal.HAS_GDAL:
raise CommandError('GDAL is required to inspect geospatial data sources.')
# Getting the OGR DataSource from the string parameter.
try:
ds = gdal.DataSource(data_source)
except gdal.GDALException as msg:
raise CommandError(msg)
# Returning the output of ogrinspect with the given arguments
# and options.
from django.contrib.gis.utils.ogrinspect import _ogrinspect, mapping
# Filter options to params accepted by `_ogrinspect`
ogr_options = {k: v for k, v in options.items()
if k in inspect.getargspec(_ogrinspect).args and v is not None}
output = [s for s in _ogrinspect(ds, model_name, **ogr_options)]
if options['mapping']:
# Constructing the keyword arguments for `mapping`, and
# calling it on the data source.
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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 = {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) + '\n'