Define the default allowlist normatively

[anssiko]

The constructors of concrete sensor specs invoke "Construct a FooSensor object" abstract operation (e.g. accelerometer and gyroscope) that in turn invokes Check sensor policy-controlled features defined in the Generic Sensor API.

These abstract operations take care of Feature Policy integration as specified in the Extending the Feature Policy API section of the Generic Sensor API except that the default allowlist is not normatively defined. It is defined in the above-mentioned non-normative section of the Generic Sensor API as follow:

The features' default allowlist is ["self"].

A proposed fix would be to make this text normative by moving it into the normative Sensor section.

[anssiko]

Just appeared to me the above proposal assumes policy-controlled features that extend Sensor would inherit its default allowlist.

@clelland given an example interface Accelerometer : Sensor { }; how to correctly define that Accelerometer inherits the default allowlist of Sensor?

[rakuco]

I think this is also related to the discussions in the DAS WG 2021 Q2 virtual meeting, where there was a resolution saying we would "Make default allowlist "self" for the Generic Sensor API, include non-normative language in concrete sensor specs to make it clear those features are Permissions Policy controlled features".

[anssiko]

I just submitted w3c/accelerometer#61

It deviates slightly from the TPAC resolution, PTAL.