DynamicArray defaults + OutputField

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1

Which tool versions are you using?

SDK: v14.21.0
Python: v3.11
Isolation mode: venv

Problem

I get a ParamNotFoundError when trying to have multiple defaults and an OutputField in a DynamicArray.

import viktor as vkt

def sum_x_y(params, **kwargs):
    return [row.x + row.y for row in params.array]

class Parametrization(vkt.Parametrization):
    array = vkt.DynamicArray("Array", default=[{"x": 2, "y": 3}, {"x": 1, "y": 4}])
    array.x = vkt.NumberField("X")
    array.y = vkt.NumberField("Y")
    array.output = vkt.OutputField("X + Y", value=sum_x_y)

class Controller(vkt.Controller):
    parametrization = Parametrization

returns a ParamNotFoundError.

Workarounds

2 solutions exist:

  1. remove default=[{"x": 2, "y": 3}, {"x": 1, "y": 4}] and instead set default values directly to x and y:

    array.x = vkt.NumberField("X", default=2)
array.y = vkt.NumberField("Y", default=3)

    But then only a single default value can be assigned per variable.

  2. move the OutputField to outside of the DynamicArray:

    def total_sum(params, **kwargs):
    rows = [row.x + row.y for row in params.array2]
    return sum(rows)

class Parametrization(vkt.Parametrization):
    array = vkt.DynamicArray("Array", default=[{"x": 2, "y": 3}, {"x": 1, "y": 4}])
    array.x = vkt.NumberField("X")
    array.y = vkt.NumberField("Y")
    output = vkt.OutputField("Total", value=total_sum)

    But then we cannot output values per row.

Conclusion

Is this a bug or un purpose? Would you know perhaps of other workarounds?

2

Hi Remi, good catch. We are looking into it.