Django GénériqueManyToMany?

Question

Je souhaite que mon modèle Book appartienne à plusieurs bibliothèques, collections, références et éditeurs. Est-il possible de le faire avec des relations génériques? Comme ça:

content_type = generic.GenericManyToMany(ContentType) 


from django.conf import settings 
from django.contrib.contenttypes import generic 
from django.contrib.contenttypes.models import ContentType 
from django.db import models 
from django.utils.translation import ugettext_lazy as _ 

LIBRARY_NAME_MAX_LENGTH = getattr(settings, "LIBRARY_NAME_MAX_LENGTH", 160) 

class Library(models.Model): 
    """ 


    """ 

    name = models.TextField(max_length=LIBRARY_NAME_MAX_LENGTH, 
           verbose_name=_(u"")) 
    desc = models.TextField() 

    class Meta: 
     verbose_name  = _(u"library") 
     verbose_name_plural = _(u"libraries") 


class Collection(models.Model): 
    """ 


    """ 

    name  = models.TextField() 
    description = models.TextField() 
    period  = models.TextField() 

    class Meta: 
     verbose_name  = _(u"collection") 
     verbose_name_plural = _(u"collections") 

class Editor(models.Model): 
    """ 
    blabla... 

    """ 

class Reference(models.Model): 
    """ 


    """ 

    title = models.TextField() 
    isbn  = models.TextField() 
    editor = models.ForeignKey(Editor) 
    pub_date = models.DateTimeField(auto_now_add=True) 

    def __unicode__(self): 
     return _(u"%s: %s") % (self.title, self.isbn) 

    class Meta: 
     ordering   = "-pub_date" 
     verbose_name  = _(u"reference") 
     verbose_name_plural = _(u"references") 

class Book(models.Model): 
    """ 


    """ 

    content_type = models.ForeignKey(ContentType) 
    object_pk  = models.TextField() 
    content_object = generic.GenericForeignKey(ct_field="content_type", 
               fk_field="object_pk") 

    title = models.TextField() 
    cover = models.TextField() 
    # and some other fields 

    class Meta: 
     verbose_name  = _(u"book") 
     verbose_name_plural = _(u"books") 

Answer 1

Je ne pense pas qu'il ya quelque chose construit dans django, mais plusieurs à plusieurs est plus ou moins juste une table de connexion.

une solution possible serait de faire quelque chose comme ceci:

class Book(models.Model): 
    pass 

class BookConnection(models.Model): 
    book = models.ForeignKey(Book) 
    content_type = models.ForeignKey(ContentType) 
    object_id = models.PositiveIntegerField() 
    content_object = generic.GenericForeignKey('content_type', 'object_id') 

class SomeModel(models.Model): 
    pass 

class SomeOtherModel(models.Model): 
    pass 

pour connecter un livre à certains modèles:

>>> book = Book.objects.create() 
>>> m1 = SomeModel.objects.create() 
>>> m2 = SomeModel.objects.create() 
>>> m3 = SomeOtherModel.objects.create() 
>>> BookConnection.objects.create(book=book, content_object=m1) 
>>> BookConnection.objects.create(book=book, content_object=m2) 
>>> BookConnection.objects.create(book=book, content_object=m3)