Transport recipes

Example languages: JavaScript/TypeScript and C. Web Bluetooth and React Native examples below adapt JavaScript values; the C recipe adapts a pointer and length. These are not transport implementations for all nine ports. Start with your language guide for its native input and ownership contracts.

These are integration examples, not additions to the protocol package. The consumer adapter seam assigns platform conversion and transport/session policy to the application while each port keeps its native byte interface. The tested conversion module and assertions run with the installed package. They perform no scanning, connecting, subscribing or writing.

Web Bluetooth

Web Bluetooth exposes a characteristic value as a DataView. Pass exactly that view’s span, not its entire backing buffer:

const bytes = new Uint8Array(value.buffer, value.byteOffset, value.byteLength);

Here value is the DataView received by your application’s notification handler. For a complete callable implementation, use parseBikeDataView from the example module. The tests use a two-byte prefix and a trailing byte outside the view, then assert the same result as the original notification. A shortened view must report truncation. The conversion creates a view, not a snapshot; copy with Uint8Array.from(bytes) if your application retains bytes from a mutable buffer.

Browser Bluetooth availability, secure-context requirements, user permission, subscription cleanup and reconnection are separate host responsibilities. Node conversion tests do not establish browser Bluetooth support.

React Native with react-native-ble-plx

The react-native-ble-plx Characteristic contract defines value as nullable Base64. Verified against that public source on 2026-09-29; confirm the contract for your installed transport version.

Install base64-js@1.5.1 in the application, then use the example module’s parseBlePlxBike(characteristic.value). It returns null for a missing transport value and otherwise converts with base64.toByteArray before parsing. Do not decode base64 as UTF-8 or pass the encoded string into the protocol API.

The host tests exercise a known base64 payload, null/undefined, wrong input type, and invalid length. base64-js is a decoder, not a general untrusted-input validation layer; validate arbitrary external text separately. BLE monitor errors must be handled before calling the conversion function. Use the transport subscription’s cleanup API when your screen/session ends.

This recipe validates conversion under Node, not Metro bundling, native permission configuration, iOS/Android behavior or a live BLE connection. No React Native dependency is added to @deancochran/ftms.

C notification buffers

The complete C client supplies a const uint8_t * and the actual received length to ftms_decode_measurement. In a notification callback, use the transport’s length—not the allocation capacity—and choose the kind from the discovered characteristic. Check both the returned ftms_result and the decoded diagnostic fields before consuming measurements.

The core does not retain the notification buffer. If the application queues processing after callback return, it must first copy bytes according to the transport’s lifetime contract. Installed headers document output/capacity and overlap rules; no platform SDK is needed to compile the host example.