Add a class-based GATT adapter #598
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| @@ -759,13 +759,13 @@ class AttributeValue: | |||
| def __init__( | |||
| self, | |||
| read: Union[ | |||
| Callable[[Optional[Connection]], bytes], | |||
| Callable[[Optional[Connection]], Awaitable[bytes]], | |||
| Callable[[Optional[Connection]], Any], | |||
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I hope this can be a TypeVar, but it might always require a type without PEP 696 which is annoying.
| @@ -735,6 +743,24 @@ def decode_value(self, value: bytes) -> str: | |||
| return value.decode('utf-8') | |||
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| # ----------------------------------------------------------------------------- | |||
| class SerializableCharacteristicAdapter(CharacteristicAdapter): | |||
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Is it possible to solve the problem that CharacteristicAdapter is not considered as a Characteristic?
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Yes, I think it's possible to do that, and it would be nice to improve type checking. Currently, the adapter classes are bit hard to deal with when it comes to types, because they are like dynamic decorators, they are polymorphic at runtime (that's convenient to reuse the code, but not convenient for typing). I have an idea about how to fix this, by splitting the adapter classes into separate classes for attributes and attribute proxies. That should solve the problem. But that's a larger change, so I'd like to do that in a separate PR.
This new adapter makes it convenient to use classes that follow the
from_bytesand__bytes__conventions. For any class that conforms to this protocol, the adapter will automatically convert GATT bytes values to/from class objects.This PR also removes the support for directly constructing a
gatt.Characteristicwith anstrvalue. Instead, callers must either perform the conversion themselves, or use the standardUT8CharacteristicAdapter. (allowing passingstrat construction was a broken API, because it would perform the conversion to bytes only at construction time, but wouldn't perform the conversion subsequently if assigning a new value. So it is better to remove it altogether.