CODEWITHSUNDEEP
django-viewflow
Sergey Gnedoy
Sergey Gnedoy

Reputation: 11

Two independent flows (processes) in Django-Viewflow under one frontend, exception raised

I'm trying to implement two identical independent Processes (flows) under one frontend. After fresh migration I can start one of them (as many times as I like) and it works fine. But when I try to start another one it raises DoesNotExist exception ("Process(Х) matching query does not exist"). After this it's not possible to start neither of them. It looks like when next node is been initialized (after start) the process object can't be found.

Update: I tried adding my app to viewflow demo. My processes is OK only when started first. Starting it after any demo processes (helloworld etc.) raises the exception. All demo processes start smoothly anytime.

The difference makes that my process model has simple custom primary key:

class Order(Process):
    order_no = models.AutoField(primary_key=True)
    ...

When I tried commenting the custom key out the problem went away.

Upvotes: 0

Views: 202

Answers (1)

Sergey Gnedoy
Sergey Gnedoy

Reputation: 11

Since it's Multi-table inheritance, OneToOneField field should be used if a custom field is needed:

class Order(Process):
    process_ptr = models.OneToOneField(
        Process, on_delete=models.CASCADE,
        parent_link=True,
    )
    ...

Upvotes: 1

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