Intent to Prototype: Web Serial connected attribute and RFCOMM connection events
Ajay Rahatekar
Contact emails
Explainer
https://github.com/WICG/serial/blob/main/EXPLAINER_BLUETOOTH.md
Specification
https://wicg.github.io/serial/#serialport-interface
Summary
This feature adds a boolean SerialPort.connected attribute. The attribute is true if the serial port is logically connected. For wired serial ports, a port is logically connected if the port is physically attached to the system. For wireless serial ports, a port is logically connected if the device hosting the port has any open connections to the host.
Previously, only wired serial ports dispatched connect and disconnect events. With this feature, Bluetooth RFCOMM serial ports will dispatch these events when the port becomes logically connected or disconnected.
This feature is intended to allow applications to detect when a Bluetooth RFCOMM serial port is available without opening the port.
Blink component
Motivation
A wireless serial port opened by an application is closed when the wireless device moves out of range of the host. In this scenario, the application that opened the wireless serial port may attempt to re-open it. However, if the wireless device was disconnected intentionally (for instance, if the user disconnected the device from the system control panel) then the application should avoid re-opening the port in order to prevent reconnecting to the device.
Exposing the logical connection state of the device hosting the wireless serial port enables applications to distinguish these cases and avoid reconnecting when the device was disconnected intentionally.
Initial public proposal
https://github.com/WICG/serial/pull/197
Search tags
serial, rfcomm, bluetooth, connect
TAG review
No TAG review is planned for this minor API change. Bluetooth RFCOMM support was previously reviewed: https://github.com/w3ctag/design-reviews/issues/854
Risks
Interoperability and Compatibility
Web Serial has not yet been adopted by other browser engines which makes this incremental change a low interoperability risk.
Gecko: Neutral (https://mozilla.github.io/standards-positions/#webserial) Deferring to the Web Serial (Add-On Gated) position. Mozilla has not commented on this specific feature.
WebKit: Negative (https://webkit.org/tracking-prevention) Apple is opposed to Web Serial API, we assume they also oppose any extensions to the API.
Web developers: Positive (requested by an internal partner)
Other signals:
WebView application risks
Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?
Web Serial API is not implemented for Android WebView.
Debuggability
None
Is this feature fully tested by web-platform-tests?
No. Web Serial tests that were previously in web-platform-tests have been temporarily moved to Chrome's wpt_internal. We plan to upstream them again after specifying a test API.
Flag name on chrome://flags
None
Finch feature name
EnableBluetoothSerialPortProfileInSerialApi
Requires code in //chrome?
False
Tracking bug
Launch bug
https://launch.corp.google.com/4297948
Estimated milestones
No milestones specified
Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/5118102654418944
This intent message was generated by Chrome Platform Status.