Mapping setting

[ziima]

We have a DictSetting and a NestedDictSetting, but we lack a setting which would define a dictionary with specific values, but various keys, such as CACHES and DATABASES.

I suggest a name MappingSetting, example:

class MySettings(appsettings.AppSettings):
    my_map = appsettings.MappingSetting(appsettings.StringSetting(), default=None)

MY_MAP = {
    'question': 'unknown',
    'answer': '42',
}

[stinovlas]

I think this is too similar to DictSetting. Why not just expand DictSetting to handle complex value types? It can already handle simple type check.

[ziima]

The complex type is another Setting, which has completely different interface than just generic type.

Or do you have any particular solution in mind?

[stinovlas]

The interface of the inner type is different, that's true. But I think we don't have to make the appsettings API more complicated. It seems to be quite confusing to have DictSetting and MappingSetting that do basically the same thing and differ only in their values types.

[ziima]

The MappingSetting is a form of a nested setting. It might be more adequate to modify NestedDictSetting instead, but it requires changes in the core anyway.

[stinovlas]

NestedDictSetting is different, because it restricts the key set, unlike the setting you want. On the other hand, DictSetting does not restrict the key set. DictSetting is much more similar to what you want from the API point of view (the implementation would need to change a lot, I agree).

[ziima]

NestedDictSetting unlike DictSetting is designed to contain another Setting within. In my opinion that's quite close also from the API point of view.