path: root/chimere/models.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (C) 2008-2012  Étienne Loks  <etienne.loks_AT_peacefrogsDOTnet>

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# See the file COPYING for details.

"""
Models description
"""
import os, string, json
import lxml.etree as ElementTree
from datetime import datetime, timedelta
from subprocess import Popen, PIPE

from django.conf import settings
from django.contrib.gis.db import models
from django.contrib.gis.gdal import SpatialReference
from django.contrib import admin
from django.core.files import File
from django.core.exceptions import ValidationError
from django import forms
from django.utils.translation import ugettext_lazy as _

from chimere.widgets import PointField, RouteField, SelectMultipleField, \
                            TextareaWidget
from chimere.managers import BaseGeoManager

class News(models.Model):
    """News of the site
    """
    title = models.CharField(_(u"Name"), max_length=150)
    available = models.BooleanField(_(u"Available"))
    date = models.DateField(_(u"Date"), auto_now_add=True)
    content = models.TextField()
    def __unicode__(self):
        ordering = ["-date"]
        return self.title
    class Meta:
        verbose_name = _(u"News")
        verbose_name_plural = _(u"News")

class TinyUrl(models.Model):
    """Tinyfied version of permalink parameters
    """
    parameters = models.CharField(_("uParameters"), max_length=500)
    def __unicode__(self):
        return self.parameters
    class Meta:
        verbose_name = _(u"TinyUrl")
    digits = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    base = len(digits)

    @classmethod
    def getParametersByUrn(cls, urn):
        c_id = 0
        for idx, char in enumerate(reversed(urn)):
            c_id += cls.digits.index(char)*pow(cls.base, idx)
        try:
            params = cls.objects.get(id=c_id).parameters
        except cls.DoesNotExist:
            return ''
        return params

    @classmethod
    def getUrnByParameters(cls, parameters):
        try:
            obj = cls.objects.get(parameters=parameters)
        except cls.DoesNotExist:
            obj = cls(parameters=parameters)
            obj.save()
        n = obj.id
        urn = ''
        while 1:
            idx = n % cls.base
            urn = cls.digits[idx] + urn
            n = n / cls.base
            if n == 0:
                break
        return urn

class ColorTheme(models.Model):
    """Color theme
    """
    name = models.CharField(_(u"Name"), max_length=150)
    def __unicode__(self):
        return self.name
    class Meta:
        verbose_name = _(u"Color theme")

class Color(models.Model):
    """Color
    """
    code = models.CharField(_(u"Code"), max_length=6)
    order = models.IntegerField(_(u"Order"))
    color_theme = models.ForeignKey(ColorTheme, verbose_name=_(u"Color theme"))
    def __unicode__(self):
        return self.code
    class Meta:
        ordering = ["order"]
        verbose_name = _(u"Color")

class Category(models.Model):
    """Category of Point Of Interest (POI)
    """
    name = models.CharField(_(u"Name"), max_length=150)
    available = models.BooleanField(_(u"Available"))
    order = models.IntegerField(_(u"Order"))
    description = models.TextField(blank=True, null=True)
    def __unicode__(self):
        return self.name
    class Meta:
        ordering = ["order"]
        verbose_name = _(u"Category")

class Icon(models.Model):
    '''Icon
    '''
    name = models.CharField(_(u"Name"), max_length=150)
    image = models.ImageField(_(u"Image"), upload_to='icons',
                              height_field='height', width_field='width')
    height = models.IntegerField(_(u"Height"))
    width = models.IntegerField(_(u"Width"))
    def __unicode__(self):
        return self.name
    class Meta:
        verbose_name = _(u"Icon")

class SubCategory(models.Model):
    '''Sub-category
    '''
    category = models.ForeignKey(Category, verbose_name=_(u"Category"))
    name = models.CharField(_(u"Name"), max_length=150)
    available = models.BooleanField(_(u"Available"))
    areas = SelectMultipleField('Area', related_name='areas', blank=True)
    icon = models.ForeignKey(Icon, verbose_name=_(u"Icon"))
    color_theme = models.ForeignKey(ColorTheme, verbose_name=_(u"Color theme"),
                                    blank=True, null=True)
    order = models.IntegerField(_(u"Order"))
    TYPE = (('M', _(u'Marker')),
            ('R', _(u'Route')),
            ('B', _(u'Both')),)
    item_type = models.CharField(_(u"Item type"), max_length=1, choices=TYPE)
    def __unicode__(self):
        return u"%s / %s" % (self.category.name, self.name)
    class Meta:
        ordering = ["category", "order"]
        verbose_name = _(u"Subcategory")

    @classmethod
    def getAvailable(cls, item_types=None, area_name=None):
        '''Get list of tuples with first the category and second the associated
        subcategories
        '''
        sub_categories = {}
        subcategories = cls.objects.filter(category__available=True)
        if not item_types:
            subcategories = subcategories.filter(available=True)
        else:
            subcategories = subcategories.filter(item_type__in=item_types)
        if area_name:
            area = Area.objects.get(urn=area_name)
            # if there some restrictions with categories limit them
            if area.subcategory_set.count():
                sub_ids = [sub.id for sub in area.subcategory_set.all()]
                # if no area is defined for a category don't filter it
                sub_ids += [sub.id for sub in subcategories
                            if not sub.areas.count()]
                subcategories = subcategories.filter(id__in=sub_ids)
        for sub_category in subcategories:
            if sub_category.category not in sub_categories:
                sub_categories[sub_category.category] = []
            if sub_category.id in settings.CHIMERE_DEFAULT_CATEGORIES:
                sub_category.selected = True
                sub_category.category.selected = True
            sub_categories[sub_category.category].append(sub_category)
        return [(category, sub_cats) for category, sub_cats \
                                         in sub_categories.items()]

class GeographicItem(models.Model):
    name = models.CharField(_(u"Name"), max_length=150)
    categories = SelectMultipleField(SubCategory)
    submiter_session_key = models.CharField(_(u"Submitter session key"),
                                        blank=True, null=True, max_length=40)
    submiter_email = models.EmailField(_(u"Submitter email"), blank=True,
                                       null=True)
    submiter_comment = models.CharField(_(u"Submitter comment"), max_length=200,
                                        blank=True, null=True)
    STATUS = (('S', _(u'Submited')),
              ('A', _(u'Available')),
              ('M', _(u'Modified')),
              ('D', _(u'Disabled')),)
    STATUS_DCT = {}
    for key, label in STATUS:
        STATUS_DCT[key] = label
    status = models.CharField(_(u"Status"), max_length=1, choices=STATUS)
    if settings.CHIMERE_DAYS_BEFORE_EVENT:
        start_date = models.DateField(_(u"Start date"), blank=True, null=True,
            help_text=_(u"Not mandatory. Set it for dated item such as event. "\
                        u"Format YYYY-MM-DD"))
        end_date = models.DateField(_(u"End date"), blank=True, null=True,
            help_text=_(u"Not mandatory. Set it only if you have a multi-day "\
                        u"event. Format YYYY-MM-DD"))
    class Meta:
        abstract = True

class Marker(GeographicItem):
    '''Marker for a POI
    '''
    ref_item = models.ForeignKey("Marker", blank=True, null=True,
            verbose_name=_(u"Reference marker"), related_name='submited_marker')
    point = PointField(_(u"Localisation"),
                       srid=settings.CHIMERE_EPSG_DISPLAY_PROJECTION)
    if 'chimere_rss' in settings.INSTALLED_APPS:
        available_date = models.DateTimeField(_(u"Available Date"), blank=True,
                                               null=True)
    route = models.ForeignKey(u"Route", blank=True, null=True,
                              related_name='associated_marker')
    pictures = models.ManyToManyField(u"PictureFile", verbose_name='Pictures',
                                      blank=True, null=True)
    multimedia_files = models.ManyToManyField(u"MultimediaFile",
                         verbose_name='Multimedia files', blank=True, null=True)
    objects = BaseGeoManager()

    def __unicode__(self):
        return self.name

    def get_init_multi(self):
        multis = [forms.model_to_dict(multi)
                  for multi in self.multimedia_files.all()]
        return multis

    def get_init_picture(self):
        picts = [forms.model_to_dict(pict)
                 for pict in self.pictures.all()]
        return picts

    @property
    def multimedia_items(self):
        pict = list(self.pictures.filter(miniature=False).all())
        mm = list(self.multimedia_files.all())
        items = [(item.order, item) for item in pict + mm]
        return [item for order, item in sorted(items)]

    @property
    def default_picture(self):
        pict = self.pictures.filter(miniature=True)
        if pict.count():
            return pict.all()[0]

    @property
    def date(self):
        if settings.CHIMERE_DAYS_BEFORE_EVENT:
            return self.start_date

    class Meta:
        ordering = ('status', 'name')
        verbose_name = _(u"Point of interest")

    def getLatitude(self):
        '''Return the latitude
        '''
        return self.point.y

    def getLongitude(self):
        '''Return the longitude
        '''
        return self.point.x

    def getProperty(self, propertymodel, safe=None):
        """Get the property of an associated property model.
        If safe set to True, verify if the property is available
        """
        if safe and not propertymodel.available:
            return
        try:
            property = Property.objects.get(propertymodel=propertymodel,
                                            marker=self)
        except Property.DoesNotExist:
            return
        return property

    def getProperties(self):
        """Get all the property availables
        """
        properties = []
        for pm in PropertyModel.objects.filter(available=True):
            property = self.getProperty(pm)
            if property:
                properties.append(property)
        return properties

    def saveProperties(self, values):
        """
        Save properties
        """
        for propertymodel in PropertyModel.objects.filter(available=True):
            properties = Property.objects.filter(marker=self,
                                          propertymodel=propertymodel).all()
            # in case of multiple edition as the same time delete arbitrary
            # the others
            if len(properties) > 1:
                for property in properties[1:]:
                    property.delete()
            val = u""
            if unicode(propertymodel.id) in values:
                val = values[unicode(propertymodel.id)]
            # new property
            if not properties:
                new_property = Property.objects.create(marker=self,
                                    propertymodel=propertymodel,
                                    value=val)
                new_property.save()
            else:
                property = properties[0]
                property.value = val
                property.save()

    def getGeoJSON(self, categories_id=[]):
        '''Return a GeoJSON string
        '''
        jsons = []
        for cat in self.categories.all():
            if categories_id and cat.id not in categories_id:
                continue
            items = {'id':self.id, 'name':json.dumps(self.name),
                     'geometry':self.point.geojson,
                     'icon_path':cat.icon.image,
                     'icon_width':cat.icon.image.width,
                     'icon_height':cat.icon.image.height,}
            jsons.append(u'{"type":"Feature", "geometry":%(geometry)s, '\
                u'"properties":{"pk": %(id)d, "name": %(name)s, '\
                u'"icon_path":"%(icon_path)s", "icon_width":%(icon_width)d, '\
                u'"icon_height":%(icon_height)d}}' % items)
        return ",".join(jsons)

    @property
    def default_category(self):
        # Should we select only available ones ?
        # Should we catch if not exists ?
        return self.categories.all()[0]

    def get_absolute_url(self):
        parameters = 'current_feature=%d&checked_categories=%s' % (self.id,
                                                    self.default_category.pk)
        return settings.BASE_URL + 'ty/' + TinyUrl.getUrnByParameters(parameters)

class MultimediaType(models.Model):
    MEDIA_TYPES = (('A', _(u"Audio")),
                   ('V', _(u"Video")),
                   ('I', _(u"Image")),
                   ('O', _(u"Other")),)
    media_type = models.CharField(_(u"Media type"), max_length=1,
                                  choices=MEDIA_TYPES)
    name = models.CharField(_(u"Name"), max_length=150)
    mime_type = models.CharField(_(u"Mime type"), max_length=50, blank=True,
                                 null=True)
    iframe = models.BooleanField(u"Inside an iframe", default=False)
    available = models.BooleanField(_(u"Available"), default=True)

    def __unicode__(self):
        return self.name

class MultimediaFile(models.Model):
    name = models.CharField(_(u"Name"), max_length=150, blank=True, null=True)
    url = models.CharField(_(u"Url"), max_length=200)
    order = models.IntegerField(_(u"Order"), default=1)
    multimedia_type = models.ForeignKey(MultimediaType, blank=True,
                                        null=True)

    def __unicode__(self):
        return self.name

    def clean(self):
        if self.url and not self.iframe:
            raise ValidationError(_(u"Multimedia type is mandatory if is "\
                                    u"not an iframe."))
        if self.multimedia_type and self.iframe:
            raise ValidationError(_(u"There is no multimedia type associated "\
                                    u"to an iframe."))

class PictureFile(models.Model):
    name = models.CharField(_(u"Name"), max_length=150, blank=True, null=True)
    picture = models.ImageField(_(u"Image"), upload_to='upload',
                                height_field='height', width_field='width')
    height = models.IntegerField(_(u"Height"))
    width = models.IntegerField(_(u"Width"))
    miniature = models.BooleanField(_(u"Display inside the resume ?"))
    order = models.IntegerField(_(u"Order"), default=1)

    def __unicode__(self):
        return self.name

class RouteFile(models.Model):
    name = models.CharField(_(u"Name"), max_length=150)
    raw_file = models.FileField(_(u"Raw file (gpx or kml)"), upload_to='upload')
    simplified_file = models.FileField(_(u"Simplified file"),
                        upload_to='upload', blank=True, null=True)
    TYPE = (('K', _(u'KML')), ('G', _(u'GPX')))
    file_type = models.CharField(max_length=1, choices=TYPE)

    class Meta:
        ordering = ('name',)
        verbose_name = _(u"Route file")

    def __unicode__(self):
        return self.name

    def process(self):
        if self.simplified_file:
            return
        input_name = settings.MEDIA_ROOT + self.raw_file.name
        output_name = settings.MEDIA_ROOT + self.raw_file.name[:-4] + \
                      "_simplified" + ".gpx"
        cli_args = [settings.GPSBABEL, '-i']
        if self.file_type == 'K':
            cli_args.append('kml')
        elif self.file_type == 'G':
            cli_args.append('gpx')
        cli_args += ['-f', input_name, '-x', settings.GPSBABEL_OPTIONS,
                     '-o', 'gpx', '-F', output_name]
        p = Popen(cli_args, stderr=PIPE)
        p.wait()
        if p.returncode:
            print p.stderr.read()
            #logger.error(p.stderr.read())
        else:
            self.simplified_file = File(open(output_name))
            self.save()
            os.remove(output_name)

    @property
    def route(self):
        if not self.simplified_file:
            return
        mainNS = string.Template("{http://www.topografix.com/GPX/1/0}$tag")
        trkpt = mainNS.substitute(tag="trkpt")
        file_name = settings.MEDIA_ROOT + self.simplified_file.name
        et = ElementTree.parse(open(file_name))
        pts = []
        for pt in et.findall("//" + trkpt):
            pts.append((pt.get("lon"), pt.get("lat")))
        geojson_tpl = u'{"type":"Feature", "geometry":{ "type": "LineString", '\
                       '"coordinates":[%s]}}'
        wkt_tpl = u'LINESTRING(%s)'
        return wkt_tpl % u','.join([u'%s %s' % (pt[0], pt[1]) \
                                           for pt in pts])

class Route(GeographicItem):
    '''Route on the map
    '''
    ref_item = models.ForeignKey("Route", blank=True, null=True,
              verbose_name=_(u"Reference route"), related_name='submited_route')
    route = RouteField(_(u"Route"),
                       srid=settings.CHIMERE_EPSG_DISPLAY_PROJECTION)
    associated_file = models.ForeignKey(RouteFile, blank=True, null=True,
                                        verbose_name=_(u"Associated file"))
    picture = models.ImageField(_(u"Image"), upload_to='upload', blank=True,
                          null=True, height_field='height', width_field='width')
    height = models.IntegerField(_(u"Height"), blank=True, null=True)
    width = models.IntegerField(_(u"Width"), blank=True, null=True)
    objects = BaseGeoManager()

    def __unicode__(self):
        return self.name

    class Meta:
        ordering = ('status', 'name')
        verbose_name = _(u"Route")

    def get_init_multi(self):
        if not self.associated_file:
            return []
        multis = [forms.model_to_dict(multi)
                  for multi in self.associated_file.multimedia_files.all()]
        return multis

    def get_init_picture(self):
        if not self.associated_file:
            return []
        picts = [forms.model_to_dict(pict)
                 for pict in self.associated_file.pictures.all()]
        return picts

    def getProperty(self, propertymodel, safe=None):
        """Get the property of an associated property model.
        If safe set to True, verify if the property is available
        """
        if safe and not propertymodel.available:
            return
        try:
            property = Property.objects.get(propertymodel=propertymodel,
                                            marker=self)
        except Property.DoesNotExist:
            return
        return property

    def getProperties(self):
        """Get all the property availables
        """
        properties = []
        for pm in PropertyModel.objects.filter(available=True):
            property = self.getProperty(pm)
            if property:
                properties.append(property)
        return properties

    def getGeoJSON(self, color="#000"):
        '''Return a GeoJSON string
        '''
        if '#' not in color:
            color = '#' + color
        attributes = {'id':self.id, 'name':json.dumps(self.name),
                      'color':color, 'geometry':self.route.geojson,}
        return u'{"type":"Feature", "geometry":%(geometry)s, '\
               u'"properties":{"pk": %(id)d, "name": %(name)s, '\
               u'"color":"%(color)s"}}' % attributes

    def getTinyUrl(self):
        parameters = 'current_feature=%d&checked_categories=%s' % (self.id,
                                                          self.categories[0].id)
        return TinyUrl.getUrnByParameters(parameters)

def getDateCondition():
    '''
    Return an SQL condition for apparition of dates
    '''
    if not settings.CHIMERE_DAYS_BEFORE_EVENT:
        return ""
    now = datetime.now().strftime('%Y-%m-%d')
    after = (datetime.now() + timedelta(settings.CHIMERE_DAYS_BEFORE_EVENT)
                                                  ).strftime('%Y-%m-%d')
    date_condition = " and %(alias)s.start_date is null or "
    date_condition += "(%(alias)s.start_date >= '" + now + "' and "
    date_condition += "%(alias)s.start_date <='" + after + "')"
    date_condition += " or (%(alias)s.start_date <='" + now + "' and "
    date_condition += "%(alias)s.end_date >='" + now + "') "
    return date_condition

class SimplePoint:
    """
    Point in the map (not in the database)
    """
    def __init__(self, x, y):
        self.x, self.y = x, y

class SimpleArea:
    """
    Rectangular area of a map (not in the database)
    """
    def __init__(self, area):
        """
        Defining upper left corner ans lower right corner from a tuple
        """
        assert len(area) == 4
        x1, y1, x2, y2 = area
        self.upper_left_corner = SimplePoint(x1, y1)
        self.lower_right_corner = SimplePoint(x2, y2)

    def isIn(self, area):
        """
        Verify if the current area is in the designated area
        """
        if self.upper_left_corner.x >= area.upper_left_corner.x and \
           self.upper_left_corner.y <= area.upper_left_corner.x and \
           self.lower_right_corner.x <= area.lower_right_corner.x and \
           self.lower_right_corner.y >= area.lower_right_corner.y:
            return True
        return False

    def getCategories(self, status='A', filter_available=True):
        """
        Get categories for this area
        """
        equal_status = ''
        if len(status) == 1:
            equal_status = "='%s'" % status[0]
        elif status:
            equal_status = " in ('%s')" % "','".join(status)
        area = u"ST_GeometryFromText('POLYGON((%f %f,%f %f,%f %f,%f %f, %f %f"\
              u"))', %d)" % (self.upper_left_corner.x, self.upper_left_corner.y,
                          self.lower_right_corner.x, self.upper_left_corner.y,
                          self.lower_right_corner.x, self.lower_right_corner.y,
                          self.upper_left_corner.x, self.lower_right_corner.y,
                          self.upper_left_corner.x, self.upper_left_corner.y,
                          settings.CHIMERE_EPSG_DISPLAY_PROJECTION
                          )
        date_condition = getDateCondition()
        sql_main = '''select subcat.id as id, subcat.category_id as category_id,
        subcat.name as name, subcat.available as available,
        subcat.icon_id as icon_id, subcat.color_theme_id as color_theme_id,
        subcat.order as order, subcat.item_type as item_type
        from chimere_subcategory subcat
        inner join chimere_category cat on cat.id=subcat.category_id'''
        sql = sql_main + '''
        inner join chimere_marker mark on ST_Contains(%s, mark.point)''' % area
        if equal_status:
            sql += ' and mark.status' + equal_status
        sql += date_condition % {'alias':'mark'}
        sql += '''
        inner join chimere_marker_categories mc on mc.subcategory_id=subcat.id and
        mc.marker_id=mark.id'''
        if filter_available:
            sql += ' where subcat.available = TRUE and cat.available = TRUE'
        subcats = set(SubCategory.objects.raw(sql))
        sql = sql_main + '''
        inner join chimere_route rt on (ST_Intersects(%s, rt.route) or
        ST_Contains(%s, rt.route))''' % (area, area)
        if equal_status:
            sql += ' and rt.status' + equal_status
        sql += date_condition % {'alias':'rt'}
        sql += '''
        inner join chimere_route_categories rc on rc.subcategory_id=subcat.id and
        rc.route_id=rt.id'''
        if filter_available:
            sql += ' where subcat.available = TRUE and cat.available = TRUE'
        subcats.union(SubCategory.objects.raw(sql))
        return subcats

class Area(models.Model, SimpleArea):
    """Rectangular area of the map
    """
    name = models.CharField(_(u"Name"), max_length=150)
    urn = models.SlugField(_(u"Area urn"), max_length=50, blank=True,
                           unique=True)
    order = models.IntegerField(_(u"Order"))
    available = models.BooleanField(_(u"Available"))
    upper_left_corner = models.PointField(_(u"Upper left corner"),
            default='POINT(0 0)', srid=settings.CHIMERE_EPSG_DISPLAY_PROJECTION)
    lower_right_corner = models.PointField(_(u"Lower right corner"),
            default='POINT(0 0)', srid=settings.CHIMERE_EPSG_DISPLAY_PROJECTION)
    objects = models.GeoManager()

    def __unicode__(self):
        return self.name

    class Meta:
        ordering = ('order', 'name')
        verbose_name = _("Area")

    @classmethod
    def getAvailable(cls):
        '''Get available areas
        '''
        return cls.objects.filter(available=True)

    def getIncludeSql(self, geometry='"chimere_marker".point'):
        """
        Get the sql statement for the test if the point is included in the area
        """
        area = "ST_GeometryFromText('POLYGON((%f %f,%f %f,%f %f,%f %f, %f %f"\
               "))', %d)" % (self.upper_left_corner.x, self.upper_left_corner.y,
          self.lower_right_corner.x, self.upper_left_corner.y,
          self.lower_right_corner.x, self.lower_right_corner.y,
          self.upper_left_corner.x, self.lower_right_corner.y,
          self.upper_left_corner.x, self.upper_left_corner.y,
          settings.EPSG_DISPLAY_PROJECTION
          )
        sql = "ST_Contains(" + area + ", " + geometry + ")"
        return sql

class PropertyModel(models.Model):
    '''Model for a property
    '''
    name = models.CharField(_(u"Name"), max_length=150)
    order = models.IntegerField(_(u"Order"))
    available = models.BooleanField(_(u"Available"))
    TYPE = (('T', _('Text')),
            ('L', _('Long text')),
            ('P', _('Password')))
    TYPE_WIDGET = {'T':forms.TextInput,
                   'L':TextareaWidget,
                   'P':forms.PasswordInput}
    type = models.CharField(_(u"Type"), max_length=1, choices=TYPE)
    def __unicode__(self):
        return self.name
    class Meta:
        ordering = ('order',)
        verbose_name = _("Property model")

    def getNamedId(self):
        '''Get the name used as named id (easily sortable)
        '''
        return 'property_%d_%d' % (self.order, self.id)

class Property(models.Model):
    '''Property for a POI
    '''
    marker = models.ForeignKey(Marker, verbose_name=_(u"Point of interest"))
    propertymodel = models.ForeignKey(PropertyModel,
                                      verbose_name=_(u"Property model"))
    value = models.TextField(_(u"Value"))
    def __unicode__(self):
        return "%s : %s" % (str(self.propertymodel), self.value)
    class Meta:
        verbose_name = _(u"Property")