How to read multiple attribute in darwin platform

[joonhaengHeo]

Reproduction steps

There is no way to read multiple attributes at once from the Darwin platform.

We have confirmed that one attribute can be read using the readAttributeWithEndpointId of MTRBaseDeviceClass, and that endpointId, clusterId, attributeId can be used as null value(nil) parameter to read all attributes. However, it is impossible to deliver in List form like Android.

connectedhomeip/src/controller/java/src/chip/devicecontroller/ChipDeviceController.java

Line 567 in 1a1d0c3

ReportCallback callback, long devicePtr, List<ChipAttributePath> attributePaths) {

Bug prevalence

always

GitHub hash of the SDK that was being used

1a1d0c3

Platform

darwin

Platform Version(s)

No response

Anything else?

No response

[bzbarsky-apple]

There is no way to read multiple attributes at once from the Darwin platform.

That is correct. That's not an API Matter.framework exposes at the moment.

Exposing such an API would require some thought about where the responsibility lies for dealing with "too large" reads (i.e. involving too many paths) and how those should be handled.

[joonhaengHeo]

@bzbarsky-apple
Thank you for your answer.

As far as I know, up to 9 multiple attributes can be read. (I received an answer to Slack question before.) Wouldn't it be right to support Multiple Attribute Read even if there is a limit of 9 Reads?

[bzbarsky-apple]

That would be one option. Another would be to accept reads of any length but break them up into 9-at-a-time, etc.

[joonhaengHeo]

Do you have a plan to add multiple attribute reading API to darwin?

[bzbarsky-apple]

Me personally, in the next few weeks, no. But I would not object to someone else doing it, as long as the API is reasonable.