Inconsistency between Pydantic model and Orange

[maxenceprog]

My issue in Darfix:

I have an output parameter a of class A.

I have an input parameter b of class B(A).

With orange current version i can connect a output to b input.

First i would expect this is not working.

Second there is an inconsistency with Pydantic and my task fail when I run it as pydantic does not accept an input of class A (And this is what i'm expecting).

Proposition of a fix:

src/ewoksorange/gui/orange_utils/_signals.py:

            if is_input:
                signal = signal_class(name=orangename, type=data_type, doc=doc)
            else:
                # To match with Pydantic Output and Input types must match exactly
                # dynamic by default is True in Orange. It means Orange accept a connection if Output type is a base type
                # of input type.
                # We do not want that so we add `dynamic=False`
                signal = signal_class(name=orangename, type=data_type, doc=doc, dynamic=False)

@payno @loichuder @woutdenolf ? What do you think ?

[loichuder]

So if I reformulate:

The issue is that you are able to connect an output A to a input B where B(A) but you should not. The output A is indeed a subset of the input B and may therefore not have all the attributes/methods to be used as B.

When running the task, the error is indeed raised so the issue lies in the Orange connection/signal code.

[loichuder]

Having dynamic=False is indeed the ideal way to fix this IMO: https://github.com/biolab/orange-canvas-core/blob/d24cbdb1245c3083476cd3bff83b8160f3b590bf/orangecanvas/scheme/link.py#L106

[loichuder]

Having dynamic=False is indeed the ideal way to fix this IMO

This breaks src/ewoksorange/tests/test_dynamic_link.py (as the name suggests). Let's wait @payno input on this before moving forward.

[woutdenolf]

I have an output parameter a of class A.

I have an input parameter b of class B(A).

With orange current version i can connect a output to b input.

Why should this not be possible? You just connect a(task A) -> b(task B). The fact that B inherits from A is irrelevant. I suspect your description is missing some crucial information?

[payno]

Maybe to see with all the code.
But:

• first check that your pydantic is well taken into account. Because there is a match to made between the input of a node and the output. Does both have models ? Else you will fall back on a more generic case.
• Again to be checked maybe at one point we will need the 'dynamic=False' but this is probably not the generic use case:

    dynamic (bool, optional):
        Specifies that the instances on the output will in general be subtypes
        of the declared type and that the output can be connected to any input
        signal which can accept a subtype of the declared output type
        (default: `True`)

[maxenceprog]

Discussed in meeting. Conclusion is:

default behaviour of orange is very weird

Let's do the proposed fix