--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django_extensions/db/fields/__init__.py Wed Jan 20 12:37:40 2010 +0100
@@ -0,0 +1,213 @@
+"""
+Django Extensions additional model fields
+"""
+
+from django.template.defaultfilters import slugify
+from django.db.models import DateTimeField, CharField, SlugField
+import datetime
+import re
+
+try:
+ import uuid
+except ImportError:
+ from django_extensions.utils import uuid
+
+class AutoSlugField(SlugField):
+ """ AutoSlugField
+
+ By default, sets editable=False, blank=True.
+
+ Required arguments:
+
+ populate_from
+ Specifies which field or list of fields the slug is populated from.
+
+ Optional arguments:
+
+ separator
+ Defines the used separator (default: '-')
+
+ overwrite
+ If set to True, overwrites the slug on every save (default: False)
+
+ Inspired by SmileyChris' Unique Slugify snippet:
+ http://www.djangosnippets.org/snippets/690/
+ """
+ def __init__(self, *args, **kwargs):
+ kwargs.setdefault('blank', True)
+ kwargs.setdefault('editable', False)
+
+ populate_from = kwargs.pop('populate_from', None)
+ if populate_from is None:
+ raise ValueError("missing 'populate_from' argument")
+ else:
+ self._populate_from = populate_from
+ self.separator = kwargs.pop('separator', u'-')
+ self.overwrite = kwargs.pop('overwrite', False)
+ super(AutoSlugField, self).__init__(*args, **kwargs)
+
+ def _slug_strip(self, value):
+ """
+ Cleans up a slug by removing slug separator characters that occur at
+ the beginning or end of a slug.
+
+ If an alternate separator is used, it will also replace any instances
+ of the default '-' separator with the new separator.
+ """
+ re_sep = '(?:-|%s)' % re.escape(self.separator)
+ value = re.sub('%s+' % re_sep, self.separator, value)
+ return re.sub(r'^%s+|%s+$' % (re_sep, re_sep), '', value)
+
+ def slugify_func(self, content):
+ return slugify(content)
+
+ def create_slug(self, model_instance, add):
+ # get fields to populate from and slug field to set
+ if not isinstance(self._populate_from, (list, tuple)):
+ self._populate_from = (self._populate_from, )
+ slug_field = model_instance._meta.get_field(self.attname)
+
+ if add or self.overwrite:
+ # slugify the original field content and set next step to 2
+ slug_for_field = lambda field: self.slugify_func(getattr(model_instance, field))
+ slug = self.separator.join(map(slug_for_field, self._populate_from))
+ next = 2
+ else:
+ # get slug from the current model instance and calculate next
+ # step from its number, clean-up
+ slug = self._slug_strip(getattr(model_instance, self.attname))
+ next = slug.split(self.separator)[-1]
+ if next.isdigit():
+ slug = self.separator.join(slug.split(self.separator)[:-1])
+ next = int(next)
+ else:
+ next = 2
+
+ # strip slug depending on max_length attribute of the slug field
+ # and clean-up
+ slug_len = slug_field.max_length
+ if slug_len:
+ slug = slug[:slug_len]
+ slug = self._slug_strip(slug)
+ original_slug = slug
+
+ # exclude the current model instance from the queryset used in finding
+ # the next valid slug
+ queryset = model_instance.__class__._default_manager.all()
+ if model_instance.pk:
+ queryset = queryset.exclude(pk=model_instance.pk)
+
+ # form a kwarg dict used to impliment any unique_together contraints
+ kwargs = {}
+ for params in model_instance._meta.unique_together:
+ if self.attname in params:
+ for param in params:
+ kwargs[param] = getattr(model_instance, param, None)
+ kwargs[self.attname] = slug
+
+ # increases the number while searching for the next valid slug
+ # depending on the given slug, clean-up
+ while not slug or queryset.filter(**kwargs):
+ slug = original_slug
+ end = '%s%s' % (self.separator, next)
+ end_len = len(end)
+ if slug_len and len(slug)+end_len > slug_len:
+ slug = slug[:slug_len-end_len]
+ slug = self._slug_strip(slug)
+ slug = '%s%s' % (slug, end)
+ kwargs[self.attname] = slug
+ next += 1
+ return slug
+
+ def pre_save(self, model_instance, add):
+ value = unicode(self.create_slug(model_instance, add))
+ setattr(model_instance, self.attname, value)
+ return value
+
+ def get_internal_type(self):
+ return "SlugField"
+
+class CreationDateTimeField(DateTimeField):
+ """ CreationDateTimeField
+
+ By default, sets editable=False, blank=True, default=datetime.now
+ """
+
+ def __init__(self, *args, **kwargs):
+ kwargs.setdefault('editable', False)
+ kwargs.setdefault('blank', True)
+ kwargs.setdefault('default', datetime.datetime.now)
+ DateTimeField.__init__(self, *args, **kwargs)
+
+ def get_internal_type(self):
+ return "DateTimeField"
+
+class ModificationDateTimeField(CreationDateTimeField):
+ """ ModificationDateTimeField
+
+ By default, sets editable=False, blank=True, default=datetime.now
+
+ Sets value to datetime.now() on each save of the model.
+ """
+
+ def pre_save(self, model, add):
+ value = datetime.datetime.now()
+ setattr(model, self.attname, value)
+ return value
+
+ def get_internal_type(self):
+ return "DateTimeField"
+
+class UUIDVersionError(Exception):
+ pass
+
+class UUIDField(CharField):
+ """ UUIDField
+
+ By default uses UUID version 1 (generate from host ID, sequence number and current time)
+
+ The field support all uuid versions which are natively supported by the uuid python module.
+ For more information see: http://docs.python.org/lib/module-uuid.html
+ """
+
+ def __init__(self, verbose_name=None, name=None, auto=True, version=1, node=None, clock_seq=None, namespace=None, **kwargs):
+ kwargs['max_length'] = 36
+ if auto:
+ kwargs['blank'] = True
+ kwargs.setdefault('editable', False)
+ self.auto = auto
+ self.version = version
+ if version==1:
+ self.node, self.clock_seq = node, clock_seq
+ elif version==3 or version==5:
+ self.namespace, self.name = namespace, name
+ CharField.__init__(self, verbose_name, name, **kwargs)
+
+ def get_internal_type(self):
+ return CharField.__name__
+
+ def create_uuid(self):
+ if not self.version or self.version==4:
+ return uuid.uuid4()
+ elif self.version==1:
+ return uuid.uuid1(self.node, self.clock_seq)
+ elif self.version==2:
+ raise UUIDVersionError("UUID version 2 is not supported.")
+ elif self.version==3:
+ return uuid.uuid3(self.namespace, self.name)
+ elif self.version==5:
+ return uuid.uuid5(self.namespace, self.name)
+ else:
+ raise UUIDVersionError("UUID version %s is not valid." % self.version)
+
+ def pre_save(self, model_instance, add):
+ if self.auto and add:
+ value = unicode(self.create_uuid())
+ setattr(model_instance, self.attname, value)
+ return value
+ else:
+ value = super(UUIDField, self).pre_save(model_instance, add)
+ if self.auto and not value:
+ value = unicode(self.create_uuid())
+ setattr(model_instance, self.attname, value)
+ return value
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