diff options
Diffstat (limited to 'tagging/fields.py')
-rw-r--r-- | tagging/fields.py | 219 |
1 files changed, 109 insertions, 110 deletions
diff --git a/tagging/fields.py b/tagging/fields.py index c9475f6..5b39e84 100644 --- a/tagging/fields.py +++ b/tagging/fields.py @@ -1,110 +1,109 @@ -"""
-A custom Model Field for tagging.
-"""
-from django.db.models import signals
-from django.db.models.fields import CharField
-from django.dispatch import dispatcher
-from django.utils.translation import ugettext_lazy as _
-
-from tagging import settings
-from tagging.models import Tag
-from tagging.utils import edit_string_for_tags
-from tagging.validators import isTagList
-
-class TagField(CharField):
- """
- A "special" character field that actually works as a relationship to tags
- "under the hood". This exposes a space-separated string of tags, but does
- the splitting/reordering/etc. under the hood.
- """
- def __init__(self, **kwargs):
- kwargs['max_length'] = kwargs.get('max_length', 255)
- kwargs['blank'] = kwargs.get('blank', True)
- kwargs['validator_list'] = [isTagList] + kwargs.get('validator_list', [])
- super(TagField, self).__init__(**kwargs)
-
- def contribute_to_class(self, cls, name):
- super(TagField, self).contribute_to_class(cls, name)
-
- # Make this object the descriptor for field access.
- setattr(cls, self.name, self)
-
- # Save tags back to the database post-save
- dispatcher.connect(self._save, signal=signals.post_save, sender=cls)
-
- def __get__(self, instance, owner=None):
- """
- Tag getter. Returns an instance's tags if accessed on an instance, and
- all of a model's tags if called on a class. That is, this model::
-
- class Link(models.Model):
- ...
- tags = TagField()
-
- Lets you do both of these::
-
- >>> l = Link.objects.get(...)
- >>> l.tags
- 'tag1 tag2 tag3'
-
- >>> Link.tags
- 'tag1 tag2 tag3 tag4'
-
- """
- # Handle access on the model (i.e. Link.tags)
- if instance is None:
- return edit_string_for_tags(Tag.objects.usage_for_model(owner))
-
- tags = self._get_instance_tag_cache(instance)
- if tags is None:
- if instance.pk is None:
- self._set_instance_tag_cache(instance, '')
- else:
- self._set_instance_tag_cache(
- instance, edit_string_for_tags(Tag.objects.get_for_object(instance)))
- return self._get_instance_tag_cache(instance)
-
- def __set__(self, instance, value):
- """
- Set an object's tags.
- """
- if instance is None:
- raise AttributeError(_('%s can only be set on instances.') % self.name)
- if settings.FORCE_LOWERCASE_TAGS and value is not None:
- value = value.lower()
- self._set_instance_tag_cache(instance, value)
-
- def _save(self, signal, sender, instance):
- """
- Save tags back to the database
- """
- tags = self._get_instance_tag_cache(instance)
- if tags is not None:
- Tag.objects.update_tags(instance, tags)
-
- def __delete__(self, instance):
- """
- Clear all of an object's tags.
- """
- self._set_instance_tag_cache(instance, '')
-
- def _get_instance_tag_cache(self, instance):
- """
- Helper: get an instance's tag cache.
- """
- return getattr(instance, '_%s_cache' % self.attname, None)
-
- def _set_instance_tag_cache(self, instance, tags):
- """
- Helper: set an instance's tag cache.
- """
- setattr(instance, '_%s_cache' % self.attname, tags)
-
- def get_internal_type(self):
- return 'CharField'
-
- def formfield(self, **kwargs):
- from tagging import forms
- defaults = {'form_class': forms.TagField}
- defaults.update(kwargs)
- return super(TagField, self).formfield(**defaults)
+""" +A custom Model Field for tagging. +""" +from django.db.models import signals +from django.db.models.fields import CharField +from django.utils.translation import ugettext_lazy as _ + +from tagging import settings +from tagging.models import Tag +from tagging.utils import edit_string_for_tags +from tagging.validators import isTagList + +class TagField(CharField): + """ + A "special" character field that actually works as a relationship to tags + "under the hood". This exposes a space-separated string of tags, but does + the splitting/reordering/etc. under the hood. + """ + def __init__(self, *args, **kwargs): + kwargs['max_length'] = kwargs.get('max_length', 255) + kwargs['blank'] = kwargs.get('blank', True) + kwargs['validator_list'] = [isTagList] + kwargs.get('validator_list', []) + super(TagField, self).__init__(*args, **kwargs) + + def contribute_to_class(self, cls, name): + super(TagField, self).contribute_to_class(cls, name) + + # Make this object the descriptor for field access. + setattr(cls, self.name, self) + + # Save tags back to the database post-save + signals.post_save.connect(self._save, cls, True) + + def __get__(self, instance, owner=None): + """ + Tag getter. Returns an instance's tags if accessed on an instance, and + all of a model's tags if called on a class. That is, this model:: + + class Link(models.Model): + ... + tags = TagField() + + Lets you do both of these:: + + >>> l = Link.objects.get(...) + >>> l.tags + 'tag1 tag2 tag3' + + >>> Link.tags + 'tag1 tag2 tag3 tag4' + + """ + # Handle access on the model (i.e. Link.tags) + if instance is None: + return edit_string_for_tags(Tag.objects.usage_for_model(owner)) + + tags = self._get_instance_tag_cache(instance) + if tags is None: + if instance.pk is None: + self._set_instance_tag_cache(instance, '') + else: + self._set_instance_tag_cache( + instance, edit_string_for_tags(Tag.objects.get_for_object(instance))) + return self._get_instance_tag_cache(instance) + + def __set__(self, instance, value): + """ + Set an object's tags. + """ + if instance is None: + raise AttributeError(_('%s can only be set on instances.') % self.name) + if settings.FORCE_LOWERCASE_TAGS and value is not None: + value = value.lower() + self._set_instance_tag_cache(instance, value) + + def _save(self, **kwargs): #signal, sender, instance): + """ + Save tags back to the database + """ + tags = self._get_instance_tag_cache(kwargs['instance']) + if tags is not None: + Tag.objects.update_tags(kwargs['instance'], tags) + + def __delete__(self, instance): + """ + Clear all of an object's tags. + """ + self._set_instance_tag_cache(instance, '') + + def _get_instance_tag_cache(self, instance): + """ + Helper: get an instance's tag cache. + """ + return getattr(instance, '_%s_cache' % self.attname, None) + + def _set_instance_tag_cache(self, instance, tags): + """ + Helper: set an instance's tag cache. + """ + setattr(instance, '_%s_cache' % self.attname, tags) + + def get_internal_type(self): + return 'CharField' + + def formfield(self, **kwargs): + from tagging import forms + defaults = {'form_class': forms.TagField} + defaults.update(kwargs) + return super(TagField, self).formfield(**defaults) |