app/django/contrib/gis/forms/fields.py
author Pawel Solyga <Pawel.Solyga@gmail.com>
Thu, 02 Apr 2009 10:11:38 +0000
changeset 2051 cecbef1289a5
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Make the mentor and organization admin comment submission on student proposal nicer. Now drop down box allows you to select comment type and based on selected type and your current Role shows you available comment options. Left TODO to put inline JS into separate JS file. Patch by: Tim Ansell (small fixes by Pawel Solyga) Reviewed by: Pawel Solyga

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