import argparse from django.contrib.gis import gdal from django.core.management.base import BaseCommand, CommandError from django.utils.inspect import get_func_args 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) 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(',')) 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', 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', 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', 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', help='Treat the geometry in the data source as a geometry collection.', ) parser.add_argument( '--name-field', help='Specifies a field name to return for the __str__() method.', ) parser.add_argument( '--no-imports', action='store_false', dest='imports', help='Do not include `from django.contrib.gis.db import models` statement.', ) parser.add_argument( '--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', 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', 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') # 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 get_func_args(_ogrinspect) 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. 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'