adapter.json, adapter.xml: Falsy Extension and Qualifier values omitted

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#682 0 comentarios 0 reacciones 0 asignados Ver en GitHub

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@LivingLikeKrillin ya está trabajando en esto.

Desde el 30/10/2026.

  • #683 de @LivingLikeKrillin — abierto

Evaluación

Dificultad
2/5
Tiempo estimado
1-3 horas
Aptitud para principiantes
85/100
Tipo de issue
Error
Claridad
Bien especificado
Estado de actividad
Activo
Stack tecnológico
python
Área
backend

Línea de trabajo

Lee sdk/basyx/aas/adapter/json/json_serialization.py y sdk/basyx/aas/adapter/xml/xml_serialization.py, centrándote en _qualifier_to_json, _extension_to_json, qualifier_to_xml y extension_to_xml. Cambia el guard if obj.value: por if obj.value is not None: en cada uno, mirroring Property serialization. Añade tests de ida y vuelta para 0, Decimal("0") y False en ambos adaptadores; done significa que los valores falsy sobreviven a serialize-deserialize.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

Description

In both adapter.json and adapter.xml, when an Extension or Qualifier has a value that evaluates to falsy in Python—such as integer 0, Decimal("0"), or False—the serializers omit the value field or attribute entirely. Non-falsy values (such as 1) are serialized as expected.

This was discovered while validating AAS JSON environments generated by an external tool, where an Extension with an xs:decimal value of "0" lost its value after being re-serialized by BaSyx.

This behavior was observed in basyx-python-sdk 2.1.0 (from PyPI) and verified on the current develop branch.

Expected vs. Actual Behaviour
  • Expected: Falsy values such as 0, Decimal("0"), and False are preserved in the serialized output.
  • Actual: The value is omitted from the serialized JSON/XML. During a round trip (serialize and then deserialize), the value becomes None, resulting in data loss. The deserializers already parse "0" correctly if the value is present.
Technical Details & Root Cause

In sdk/basyx/aas/adapter/json/json_serialization.py:

  • _qualifier_to_json and _extension_to_json guard the value using if obj.value:.

In sdk/basyx/aas/adapter/xml/xml_serialization.py:

  • qualifier_to_xml and extension_to_xml guard the value using if obj.value:.

Because 0, Decimal("0"), and False evaluate to False in Python boolean evaluation, the value is not written. For comparison, Property serialization already uses if obj.value is not None:.

Reproduction
import io, json
from basyx.aas import model
from basyx.aas.adapter import json as aas_json

sm = model.Submodel(
    "https://example.org/sm",
    extension=[model.Extension("e", value_type=model.datatypes.Int, value=0)],
    qualifier=[model.Qualifier("q", value_type=model.datatypes.Int, value=0)],
)
buf = io.StringIO()
aas_json.write_aas_json_file(buf, model.DictIdentifiableStore([sm]))
print(json.loads(buf.getvalue())["submodels"][0]["extensions"])
# [{'valueType': 'xs:int', 'name': 'e'}]  -- no "value"

The qualifier output also lacks the "value" field. The XML adapter exhibits the same behavior.

Suggested Fix

Update _qualifier_to_json, _extension_to_json, qualifier_to_xml, and extension_to_xml to check if obj.value is not None:, matching the implementation in Property.

A pull request containing this fix alongside round-trip tests for 0, Decimal("0"), and False in both adapters will be submitted and reference this issue.

Lenguaje dominante
Python
Estrellas
107
Forks
61
Merge medio
1 h 9 min
PR fusionados (30 d)
2

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