dss/spa/models/_BaseModel.py

import logging
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.db.models import ForeignKey
from django.utils import simplejson
import os
from polymodels.models import BasePolymorphicModel
from core.utils import url
from dss import localsettings, settings

class _BaseModel(BasePolymorphicModel):
    logger = logging.getLogger(__name__)
    content_type = ForeignKey(ContentType, null=True)
    CONTENT_TYPE_FIELD = 'content_type'

    class Meta:
        abstract = True
        app_label = 'spa'

    def tosimplejson(self):
        ret = simplejson.dump(self)

    @classmethod
    def get_lookup(cls, filter_field, transform=None, filter=None):
        if filter is not None:
            filter_dict = {'%s__startswith' % filter_field: filter}
            return cls.objects.all().filter(filter_dict).extra(select=transform)
        else:
            return cls.objects.all()

    def get_image_url(self, image, default):
        try:
            if os.path.isfile(image.path):
                images_root = localsettings.IMAGE_URL if hasattr(localsettings, 'IMAGE_URL') else "%s" % settings.MEDIA_URL
                ret = "%s/%s" % (images_root, image)
                return url.urlclean(ret)

        except Exception, ex:
            pass

        return default

    @classmethod
    def get_lookup_filter_field(cls):
        field_list = cls._meta.get_all_field_names()
        for field in field_list:
            if field.endswith("name") or field.endswith("description"):
                return field
        return "description"

    def base_pre_save(self, sender, instance, created, **kwargs):
        pass

    def clean_image(self, image_field, sender):
        if self.__dict__[image_field] == "DONOTSEND":
            try:
                old_instance = sender.objects.get(pk=self.pk)
                if old_instance is not None:
                    self.__dict__[image_field] = old_instance.__dict__[image_field]
            except Exception, ex:
                pass