Source code for mezzanine.utils.models

from __future__ import unicode_literals

import warnings

from future.utils import with_metaclass

from django.conf import settings
from django.contrib.auth import get_user_model as django_get_user_model
from django.core.exceptions import ImproperlyConfigured
from django.db.models import Model, Field

from mezzanine.utils.importing import import_dotted_path

def get_user_model():
        "Mezzanine's get_user_model() is deprecated and will be removed in a "
        "future version. Replace all uses of this function with Django's "
    return django_get_user_model()

[docs]def get_user_model_name(): """ Returns the app_label.object_name string for the user model. """ return getattr(settings, "AUTH_USER_MODEL", "auth.User")
def _base_concrete_model(abstract, klass): for kls in reversed(klass.__mro__): if issubclass(kls, abstract) and not kls._meta.abstract: return kls
[docs]def base_concrete_model(abstract, model): """ Used in methods of abstract models to find the super-most concrete (non abstract) model in the inheritance chain that inherits from the given abstract model. This is so the methods in the abstract model can query data consistently across the correct concrete model. Consider the following:: class Abstract(models.Model) class Meta: abstract = True def concrete(self): return base_concrete_model(Abstract, self) class Super(Abstract): pass class Sub(Super): pass sub = Sub.objects.create() sub.concrete() # returns Super In actual Mezzanine usage, this allows methods in the ``Displayable`` and ``Orderable`` abstract models to access the ``Page`` instance when instances of custom content types, (eg: models that inherit from ``Page``) need to query the ``Page`` model to determine correct values for ``slug`` and ``_order`` which are only relevant in the context of the ``Page`` model and not the model of the custom content type. """ if hasattr(model, 'objects'): # "model" is a model class return (model if model._meta.abstract else _base_concrete_model(abstract, model)) # "model" is a model instance return ( _base_concrete_model(abstract, model.__class__) or model.__class__)
[docs]def upload_to(field_path, default): """ Used as the ``upload_to`` arg for file fields - allows for custom handlers to be implemented on a per field basis defined by the ``UPLOAD_TO_HANDLERS`` setting. """ from mezzanine.conf import settings for k, v in settings.UPLOAD_TO_HANDLERS.items(): if k.lower() == field_path.lower(): return import_dotted_path(v) return default
[docs]class AdminThumbMixin(object): """ Provides a thumbnail method on models for admin classes to reference in the ``list_display`` definition. """ admin_thumb_field = None def admin_thumb(self): thumb = "" if self.admin_thumb_field: thumb = getattr(self, self.admin_thumb_field, "") if not thumb: return "" from mezzanine.conf import settings from mezzanine.core.templatetags.mezzanine_tags import thumbnail x, y = settings.ADMIN_THUMB_SIZE.split('x') thumb_url = thumbnail(thumb, x, y) return "<img src='%s%s'>" % (settings.MEDIA_URL, thumb_url) admin_thumb.allow_tags = True admin_thumb.short_description = ""
[docs]class ModelMixinBase(type): """ Metaclass for ``ModelMixin`` which is used for injecting model fields and methods into models defined outside of a project. This currently isn't used anywhere. """ def __new__(cls, name, bases, attrs): """ Checks for an inner ``Meta`` class with a ``mixin_for`` attribute containing the model that this model will be mixed into. Once found, copy over any model fields and methods onto the model being mixed into, and return it as the actual class definition for the mixin. """ if name == "ModelMixin": # Actual ModelMixin class definition. return super(ModelMixinBase, cls).__new__(cls, name, bases, attrs) try: mixin_for = attrs.pop("Meta").mixin_for if not issubclass(mixin_for, Model): raise TypeError except (TypeError, KeyError, AttributeError): raise ImproperlyConfigured("The ModelMixin class '%s' requires " "an inner Meta class with the " "``mixin_for`` attribute defined, " "with a value that is a valid model.") # Copy fields and methods onto the model being mixed into, and # return it as the definition for the mixin class itself. for k, v in attrs.items(): if isinstance(v, Field): v.contribute_to_class(mixin_for, k) elif k != "__module__": setattr(mixin_for, k, v) return mixin_for
[docs]class ModelMixin(with_metaclass(ModelMixinBase, object)): """ Used as a subclass for mixin models that inject their behaviour onto models defined outside of a project. The subclass should define an inner ``Meta`` class with a ``mixin_for`` attribute containing the model that will be mixed into. """