timedelta field converts to datetime in the forms

[regisin]

I have a model with a timedelta property. SQLAlchemy treats it correctly on the db side (it's Interval type: Interval).

However, in the admin panel, it is converted and treated as datetime, which is incompatible with the db. If I try to save it raises an exception.

Is there a way to override the original form?

I envision a form having several number <input> fields, one for each timedelta attribute.

Where should I start looking into?

[jowilf]

The interval is treated as datetime due to the impl attribute in the Interval type which is Datetime.

You can create a custom field and add a converter for it. Here is how you can do it

class MyCustomIntervalField(BaseField):
    ....

class MyCustomConverter(ModelConverter): # from sqla.converters
    @converts("Interval")
    def conv_interval(self, *args: Any, **kwargs: Any) -> BaseField:
        return MyCustomIntervalField(... )

admin.add_view(ModelView(MyModel, converter=MyCustomConverter()))

For more info:

• https://jowilf.github.io/starlette-admin/advanced/custom-field
• https://github.com/jowilf/starlette-admin/blob/main/starlette_admin/contrib/sqla/converters.py
• Add TinyMCEEditorField #131

Also feel free to contribute back, it would be good to have a field for Interval by default

[regisin]

I think I'm almost there. Last night I didn't look into the converters, so I'm putting most of the logic in the custom field class. Creating/editing a record and displaying in the list works fine (haven't done the display template yet).

Is using this converter a better way? I never noticed it was a thing..

[regisin]

Submitted #573