title: django rights of access users
body: <p>I have materials recorded in the database and belonging to different users. those are either private access, or are part of a group, or free access to all.
  I want, for example, a current user can have access to all the materials open access (but can not modify those he did not create (readonly fields). But, He could add other records ..</p>
  
  <p>I have a model</p>
  
  <pre><code>DROITS = (
  ('lecture', 'all'),
  ('groupe', 'group')
  ('private', 'private data')
  
  class Material(models.Model):
      name = models.CharField(_('name'), max_length=50)
      category = models.ForeignKey(Category, verbose_name=_('category'))
      user = models.ForeignKey(User, default=None, blank= True, null = True)
      droits_acces = models.CharField(_('access right'), max_length=150, choices =      DROITS, default= 'private' )
      groupe = models.ForeignKey(Group,  verbose_name=_('group'), blank = True, null= True, default = None)
  </code></pre>
  
  <p>Admin :</p>
  
  <pre><code>class MaterialAdmin(admin.ModelAdmin):
     list_display = ('name', 'description', 'user', 'created', 'droits_acces')
     inlines = (MediaInline, UniteProperty2Inline, Essai_TemperatureInline)
     def queryset(self, request):
     qs = super(MaterialAdmin, self).queryset(request)
     if request.user.is_superuser:
        return qs
     else:
  .....
  </code></pre>
  
  <p>the first thing is to associate user and material.
  how can we do?
  with the class Material, I filter only the fields related material</p>
  
  <p>after if the material does not belong to the current user I have to put  'Essai_TemperatureInline' read access only</p>