Self-referential nested fields not parsed correctly about apispec HOT 5 CLOSED

FYI, by accident I got this working. If you change 'self' to the name of the schema you're self-referencing, APISpec doesn't blow up.

Like so:

class EntitySchema(ModelSchema):
    children = fields.Nested('EntitySchema', many=True)
    class Meta:
        model = Entity
        sqla_session = session
        include_fk = True

Not sure if this would be expected or desired behavior so leaving this open for now.

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Thanks for the update, @whoiswes . I'm glad you found a workaround, but this still looks to be a bug--passing 'self' should not break the code.

I would be open to a PR for this.

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This bug is now fixed on dev.

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Hi, Can you explain to me the part of this fix:

is_unbound_self_referencing = not getattr(field, 'parent', None) and field.nested == 'self'

How might a self-referencing Nested field be 'bounded'?
Is the test for a parent is the same as a test for being an instance of SchemaABC (top-level abs baseclass)?

I am getting a MaxRecursion error on a self-referencing Nested field. This is fixed by adding a ref, but I'm curious why it is not USR without - the test for there being no parent fails, so the code here doesn't seem to handle.

Regards.

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oooh, I think I see now - it if you supply a definition via:

spec.definition('foo', schema=FooSchema)

It will then be a "top-level" object since it has its own definition.
Then the name ('foo') is used to fill in the ref.

Is it possible to raise an exception when the object is self-referential but not top-level?
i.e."Self-referencing schema must provide named definition".

Incidentally, what happens when there are Schema that don't involve self-reference, but are recursive, e.g. involving two elements that refer to each other, A -> B -> A -> B -> A -> ...

If neither provides a definition then the same MaxRecursion will occur, without a Nested 'self'?

Regards.

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