app/django/contrib/gis/forms/fields.py
author Lennard de Rijk <ljvderijk@gmail.com>
Fri, 23 Oct 2009 13:25:28 -0700
changeset 3032 f3886d1b00a5
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Changed checkCanMakeRequestToGroup to use Logic instance instead of module. This method now also directly queries for the keyname of the group. Also some whitespace fixes in the access module.

from django import forms
from django.contrib.gis.db.backend import SpatialBackend
from django.utils.translation import ugettext_lazy as _

class GeometryField(forms.Field):
    """
    This is the basic form field for a Geometry.  Any textual input that is
    accepted by SpatialBackend.Geometry is accepted by this form.  By default, 
    this is GEOSGeometry, which accepts WKT, HEXEWKB, WKB, and GeoJSON.
    """
    widget = forms.Textarea

    default_error_messages = {
        'no_geom' : _(u'No geometry value provided.'),
        'invalid_geom' : _(u'Invalid geometry value.'),
        'invalid_geom_type' : _(u'Invalid geometry type.'),
    }

    def __init__(self, **kwargs):
        self.null = kwargs.pop('null')
        self.geom_type = kwargs.pop('geom_type')
        super(GeometryField, self).__init__(**kwargs)

    def clean(self, value):
        """
        Validates that the input value can be converted to a Geometry
        object (which is returned).  A ValidationError is raised if
        the value cannot be instantiated as a Geometry.
        """
        if not value:
            if self.null:
                # The geometry column allows NULL, return None.
                return None
            else:
                raise forms.ValidationError(self.error_messages['no_geom'])
     
        try:
            # Trying to create a Geometry object from the form value.
            geom = SpatialBackend.Geometry(value)
        except:
            raise forms.ValidationError(self.error_messages['invalid_geom'])
  
        # Ensuring that the geometry is of the correct type (indicated
        # using the OGC string label).
        if str(geom.geom_type).upper() != self.geom_type and not self.geom_type == 'GEOMETRY':
            raise forms.ValidationError(self.error_messages['invalid_geom_type'])

        return geom