Access parent object fields of save_formset and save_model

Question

I have a ActionAdmin model, which is used as ActionAdminInline in the InvoiceAdmin model.

In InvoiceModel i override save_formset, to auto set some values. Setting the values for each Action instance is no problem, but i could not get the fields of the parent Invoice.

I thought it had to be self or self.project.pk I also tried to get it by form.project.pk seen in some other thread.

The errors i get, are about no such Field in InvoiceAdmin. That makes sense to me, self is an InvoiceAdmin object and not an Invoice object. I think i had to get the Invoice object fields to set Action instance.invoice and instance.project.

Does somebody know, how to get this parent object values ???

looks like this:

class ActionAdmin(admin.ModelAdmin):
...


class ActionInlineForm(ModelForm):
    class Meta:
        model = Action
        fields = ['name','tax', 'price','duration_extern',]


class ActionInline(admin.TabularInline):
    model = Action
    form = ActionInlineForm
    extra = 0
    ordering = ('date_finished',)
    can_delete=False
    readonly_fields = ['non_editable_date_finished','non_editable_duration','get_remove_invoice_pos_link']




class InvoiceAdmin(admin.ModelAdmin):
...
...
...
  inlines = [ActionInline,]
  ...
  ...
  ...
  def save_formset(self, request, form, formset, change):
      instances = formset.save(commit=False)
      for instance in instances:
          usr = User.objects.get(id=7)
          try:
            instance.created_by = instance.created_by
          except:
            instance.created_by = usr

          try:
            instance.owner = instance.owner
          except:
            instance.owner = usr

          instance.modified_by = usr

          try:
            instance.date_created = instance.date_created
          except:
            instance.date_created = date.today

          instance.date_modified = date.today:

          ### MAN, This WORKS NOW ###
          try:
              instance.project = instance.project
          except:
            pr = Project.objects.get(id=instance.invoice.project.id)
            instance.project = pr


          actstat = ActionStatus.objects.get(id=2)
          instance.actionstatus = actstat

          try:
            instance.actioncategory = instance.actioncategory
          except:
            cat = ActionCategory.objects.get(id=9)
            instance.actioncategory = cat

          instance.done = True
          instance.billed = True    
          instance.save()
      formset.save_m2m()

This is the error message:

AttributeError at /workflow/invoice/21/
    ...
    Exception Type:     AttributeError
    Exception Value:    'InvoiceAdmin' object has no attribute 'id'
    ...

Traceback
    form <django.forms.models.InvoiceForm object at 0x7f7f7421de10>
    instances [<Action: aaaaa>]
    self <workflow.admin.InvoiceAdmin object at 0x7f7f7421dad0>

Is it the problem, that the self object is InvoiveAdmin and not Invoice? I mean the instances objects are Action and not ActionAdmin?!

Answer 1

OK. i found a solution for instance.invoice. It's correctly set without doing anything for instance.invoice. I removed the line "instance.invoice = self" from the code above.

The solution to get the project by parent object, which is an invoice is done by "instance.invoice.project.id"

So i traverse form action to invoice to project an than to it's id. Changed this also above.

And it's nescessary to check instance fields with try,except. First i tried
if not instance.project
and
if not hasatrr(instance,'project')
or
if instance.project=""
But without exception handling it raises an DoesNotExists error. Changed it from if/else to try/except above.

---

BTW

Realy rare. I'm just changing something in ActionAdmin save_model
When i try to proove instance field there, the same way with try/except like in save_formset, i don't works.

In save_model i had to do:

 if not instance.price:
        instance.price = instance.project.customer.price

this fails

  try:
      instance.price = instance.price
  except:
      instance.price = instance.project.customer.price

And in save_formset it's viceversa ??? !

Somebody could explain that to me?