title: Save the related objects before the actual object being edited on django admin
body: <p>Is it possible to save the related objects before the actual object being edited on a django admin form?</p>
  
  <p>For example:</p>
  
  <p>in <code>models.py</code></p>
  
  <pre><code>class Parent(model.Model):
      pass
  
  class Child(model.Model):
      parent = models.ForeignKey(Parent)
  
  @receiver(post_save,sender = Parent)
  def notify_parent_save(sender, instance=None, **kwargs):
      print "Parent save"
  
  @receiver(post_save,sender = Child)
  def notify_child_save(sender, instance=None, **kwargs):
      print "Child saved"
  </code></pre>
  
  <p>in <code>admin.py</code></p>
  
  <pre><code>class ChildInline(admin.TabularInline):
      model = Child
      extra = 1
  
  class ParentsAdmin(admin.ModelAdmin):
      inlines = [ChildInline]
  
  admin.site.register(Parent,ParentsAdmin)
  </code></pre>
  
  <p>Now, in django admin if I save a parent object, it will output on the console.</p>
  
  <pre><code>Parent save
  Child save
  </code></pre>
  
  <p>I need this to happen in revese order:</p>
  
  <pre><code>Child save
  Parent save
  </code></pre>