tastyhacks.py

# Appropriated with license from https://github.com/newsapps/django-boundaryservice/blob/master/boundaryservice/tastyhacks.py

# The MIT License
#
#Copyright (c) 2011 Chicago Tribune, Christopher Groskopf, Ryan Nagle
#
#Permission is hereby granted, free of charge, to any person obtaining a copy
#of this software and associated documentation files (the "Software"), to deal
#in the Software without restriction, including without limitation the rights
#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#copies of the Software, and to permit persons to whom the Software is
#furnished to do so, subject to the following conditions:
#
#The above copyright notice and this permission notice shall be included in
#all copies or substantial portions of the Software.
#
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#THE SOFTWARE.

from django.contrib.gis.db.models import GeometryField
from django.utils import simplejson

from tastypie.bundle import Bundle
from tastypie.fields import ApiField, CharField
from tastypie.resources import ModelResource


class GeometryApiField(ApiField):
    """
    Custom ApiField for dealing with data from GeometryFields (by serializing them as GeoJSON).
    """
    dehydrated_type = 'geometry'
    help_text = 'Geometry data.'

    def hydrate(self, bundle):
        value = super(GeometryApiField, self).hydrate(bundle)
        if value is None:
            return value
        return simplejson.dumps(value)

    def dehydrate(self, obj):
        return self.convert(super(GeometryApiField, self).dehydrate(obj))

    def convert(self, value):
        if value is None:
            return None

        if isinstance(value, dict):
            return value

        # Get ready-made geojson serialization and then convert it _back_ to a Python object
        # so that Tastypie can serialize it as part of the bundle
        return simplejson.loads(value.geojson)


class GeoResource(ModelResource):
    """
    ModelResource subclass that handles geometry fields as GeoJSON.
    """

    @classmethod
    def api_field_from_django_field(cls, f, default=CharField):
        """
        Overrides default field handling to support custom GeometryApiField.
        """
        if isinstance(f, GeometryField):
            return GeometryApiField

        return super(GeoResource, cls).api_field_from_django_field(f, default)

import base64
from tastypie.fields import FileField
from django.core.files.uploadedfile import SimpleUploadedFile


class Base64FileField(FileField):
    """
    A django-tastypie field for handling file-uploads through raw post data.
    It uses base64 for en-/decoding the contents of the file.

    Usage:

        class MyResource(ModelResource):
            file_field = Base64FileField("file_field")

            class Meta:
                queryset = ModelWithFileField.objects.all()

    In the case of multipart for submission, it would also pass the filename.
    By using a raw post data stream, we have to pass the filename within our
    file_field structure:

        file_field = {"name": "myfile.png", "file": "longbas64encodedstring"}
    """

    def hydrate(self, obj):
        value = super(Base64FileField, self).hydrate(obj)
        if value:
            value = SimpleUploadedFile(value["name"], base64.b64decode(value["file"]))
            return value
        return None