Django temporary fields only upon creation - django

Question

Consider two models:
Contract
class Contract(models.Model):
employee = models.OneToOneField(Employee, on_delete=models.CASCADE)
contract_type = models.ForeignKey(ContractType, on_delete=models.CASCADE)
start_date = models.DateField()
end_date = models.DateField()
and
Employee
class Employee(models.Model):
first_name = models.CharField(max_length=20)
last_name = models.CharField(max_length=20)
contract = models.OneToOneField(Contract, on_delete=models.CASCADE, null=True, blank=True)
I was wondering if there's a way to add temporary fields in a model form that are only shown upon creation in the Employee model so I can add all those fields while I create a new Employee then when saving, I first create an Employee object, then automatically generate a Contract object and edit the original Employee object and link the now generated Contract object.
I really hope this makes sense, and if it does, can someone guide me in the right direction?
Thank you, for your time reading this.

Answer 1

First of all, you here made two relations between Employee and Contract. Django automatically makes a relation in reverse, so you probably should remove one. Otherwise it is possible that some_contract.emplyee.contract is not the same as some_contract.
You thus for example might want to re-model this to:
class Employee(models.Model):
first_name = models.CharField(max_length=20)
last_name = models.CharField(max_length=20)
class Contract(models.Model):
employee = models.OneToOneField(Employee, on_delete=models.CASCADE, related_name='contract')
contract_type = models.ForeignKey(ContractType, on_delete=models.CASCADE)
start_date = models.DateField()
end_date = models.DateField()
You can just create two ModelForms:
# app/forms.py
from app.models import Employee, Contract
class EmployeeForm(ModelForm):
class Meta:
model = Employee
exclude = ['contract']
class ContractForm(ModelForm):
class Meta:
model = Contract
Then we can render the two forms:
# app/views.py
from django.shortcuts import redirect, render
from app.forms import EmployeeForm, ContractForm
def some_view(request):
if request.method == 'POST':
employee_form = EmployeeForm(request.POST)
contract_form = ContractForm(request.POST)
if employee_form.is_valid() and contract_form.is_valid():
employee = employee_form.save()
contract_form.instance.employee = employee
contract_form.save()
return redirect('some-view')
else:
employee_form = EmployeeForm()
contract_form = ContractForm()
return render(
request,
'some_template.html',
{'employee_form': employee_form, 'contract_form': contract_form}
)
in the template, we then render the two forms in the same <form> tag:
<!-- some_template.html -->
<form method="post">
{% csrf_token %}
{{ employee_form }}
{{ contract_form }}
<button type="submit">submit</button>
</form>