I followed this: https://www.yergler.net/2009/09/27/nested-formsets-with-django/ and this: django inline formsets with a complex model for the nested form and overall my code works great.
class Account(models.Model):
user_username = models.ForeignKey(User, on_delete=models.CASCADE)
account_name = models.CharField(max_length=30)
class Classification(models.Model):
user_username=models.ForeignKey(User, on_delete=models.CASCADE)
data_id=models.ForeignKey(ImportData, on_delete=models.CASCADE)
class ImportData(models.Model):
user_username = models.ForeignKey(User, on_delete=models.CASCADE)
data_id = models.UUIDField(
primary_key=True, default=uuid.uuid4, editable=False)
ClassificationFormset = inlineformset_factory(ImportData, Classification, exclude=('user_username',), extra=1)
# below is just what came from the nested formset links above: pasted here for easy reference.
class BaseNestedTransactionFormset(BaseInlineFormSet):
def add_fields(self, form, index):
# allow the super class to create the fields as usual
super(BaseNestedTransactionFormset, self).add_fields(form, index)
try:
instance = self.get_queryset()[index]
pk_value = instance.pk
except IndexError:
instance=None
pk_value = hash(form.prefix)
transaction_data = None
if (self.data):
transaction_data = self.data;
# store the formset in the .nested property
form.nested = [
CategoryFormset(data=transaction_data,
instance = instance,
prefix = 'CAT_%s' % pk_value)]
def is_valid(self):
result = super(BaseNestedTransactionFormset, self).is_valid()
for form in self.forms:
if hasattr(form, 'nested'):
for n in form.nested:
# make sure each nested formset is valid as well
result = result and n.is_valid()
return result
def save_new(self, form, commit=True):
"""Saves and returns a new model instance for the given form."""
instance = super(BaseNestedTransactionFormset, self).save_new(form, commit=commit)
# update the form’s instance reference
form.instance = instance
# update the instance reference on nested forms
for nested in form.nested:
nested.instance = instance
# iterate over the cleaned_data of the nested formset and update the foreignkey reference
for cd in nested.cleaned_data:
cd[nested.fk.name] = instance
return instance
def save_all(self, commit=True):
"""Save all formsets and along with their nested formsets."""
# Save without committing (so self.saved_forms is populated)
# — We need self.saved_forms so we can go back and access
# the nested formsets
objects = self.save(commit=False)
# Save each instance if commit=True
if commit:
for o in objects:
o.save()
# save many to many fields if needed
if not commit:
self.save_m2m()
# save the nested formsets
for form in set(self.initial_forms + self.saved_forms):
# if self.should_delete(form): continue
for nested in form.nested:
nested.save(commit=commit)
ImportTransactionFormset = inlineformset_factory(Account, ImportData, exclude=('user_username',), formset=BaseNestedTransactionFormset, extra=0)
My template has a table that displays the import data formset... user selects the account and the table shows all the imported data from that account. For each of these row forms, there is a hidden row underneath... user clicks a button to show that hidden row. The hidden row displays the nested classification formset.
If include the user_username field in the template and allow for it to be part of the nested formset in the template, i can set is accordingly in the html form and the formsets save no problem.
However: I want to be able to exclude the user_username field from the template and have my view or some other method under the BaseNestedTransactionFormset class set the value of the user_username field to request.user value for whoever is logged in at that time.
I tried to override the clean method, but cleaned_data kicks back an error because the form doesnt validate; the field is required. I can't seem to figure out a good way to do this.
If this was a normal formset, not too hard to do. I would just set the field by modifying what comes back from POST. I have never worked with nested inline formsets, and the prefixes and indeces in the field names have got me. I've been at this for a couple of days and can't seem to be getting anywhere.
I am also contemplating just getting rid of that field from the classification model, since it is already tied to the ImportData model which is linked to the logged in user regardless. I'm just thinking i may run into this at some point again, so maybe good to solve.
Thanks in advance.
