Known issues and how to resolve them

There are some common pitfalls that you may encounter when working with the platform code and/or frameworks. This page contains a list of errors you may come across and how to resolve them.

Object not JSON-serialisable

Some database schemas contain jsonb columns, which means that you can store "any" Python dict as a json-encoded string and the database will know how to deal with it. On query time, SQLAlchemy will respond also with the resolved object (i.e. converts the string to a dict for you).
Internally, we use pydantic to describe how these dicts are supposed to "look" like. It might happen, that you want to store the pydantic model directly and on session.commit(), you may get an error message that looks/contains something like that:

[...]
TypeError: Object of type AnnotationSchemeLabel is not JSON serializable
[...]
StatementError: (builtins.TypeError) Object of type AnnotationSchemeLabel is not JSON serializable
[SQL: INSERT INTO annotation_scheme (annotation_scheme_id, project_id, name, description, labels) VALUES (%(annotation_scheme_id)s::UUID, %(project_id)s::UUID, %(name)s, %(description)s, %(labels)s)]
[...]

What happened here is, that the engine tried to transform the object (i.e. pydantic model) to a JSON string but failed to do so (even though, pydantic implements JSON serialisation...). Consider the following example:

from nacsos_data.models.annotations import AnnotationSchemeLabel
from nacsos_data.db.schemas.annotations import AnnotationScheme
label1 = AnnotationSchemeLabel(
    name = 'Relevant',
    key = 'r_1234',
    hint = 'Mark whether this is relevant or not',
    max_repeat = 1,
    required = True,
    kind = 'bool' 
)

anno_scheme = AnnotationScheme(
    project_id = pm.project_id,
    name = 'Policy Instruments',
    labels = [label1] 
)
session.add(anno_scheme)
session.commit()

A quick way to resolve this issue is to convert the pydantic model (label1) to a dict before saving:

anno_scheme = AnnotationScheme(
    project_id = pm.project_id,
    name = 'Policy Instruments',
    labels = [label1.dict()] 
)
session.add(anno_scheme)
session.commit()