Alex2Node/examples/sensor.js
David 8379a65d78 examples: one runnable file per recipe on the 2.0 API, the 1.x files in examples/legacy
Ten recipes: lamp, colour lamp, thermostat, blind, lock (deferred), contact
sensor (ChangeReport), scene, doorbell (raise), typed errors, and a plug as an
ES module. Each reads ALEX2MQTT_USERNAME, _PASSWORD and _ROOT_TOPIC and names
the ones that are missing. The nine examples of 1.5.2 move to examples/legacy
unchanged.

test/examples.test.js starts every file with node, its broker connection sent
to a broker on 127.0.0.1 (test/helpers/loopback.js), discovers the device,
sends directives and checks the answers. A legacy file is started and its
discovery compared with the answer the 1.5.2 build gave, recorded in
test/fixtures/legacy-examples.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-28 21:38:07 +00:00

40 lines
2.1 KiB
JavaScript

// A contact sensor on a door: Alexa.ContactSensor. It takes no directive. It answers ReportState and sends a
// ChangeReport when the door opens or closes. Press Enter to open and close the door.
//
// ALEX2MQTT_USERNAME=... ALEX2MQTT_PASSWORD=... ALEX2MQTT_ROOT_TOPIC=... node examples/sensor.js
//
// "alex2node" is the installed package; inside this checkout it resolves to the built dist/.
const { Alex2MQTT, ContactSensor } = require("alex2node");
const missing = ["ALEX2MQTT_USERNAME", "ALEX2MQTT_PASSWORD", "ALEX2MQTT_ROOT_TOPIC"].filter((name) => !process.env[name]);
if (missing.length > 0) {
console.error(`${missing.join(", ")} not set. Set the MQTT user name, the password and the root topic of your Alex2MQTT account.`);
process.exit(1);
}
const { ALEX2MQTT_USERNAME, ALEX2MQTT_PASSWORD, ALEX2MQTT_ROOT_TOPIC } = process.env;
const bridge = new Alex2MQTT(ALEX2MQTT_USERNAME, ALEX2MQTT_PASSWORD, ALEX2MQTT_ROOT_TOPIC);
bridge.on("connect", () => console.log("connected, discover the devices in the Alexa app"));
bridge.on("error", (err) => console.error("bridge:", err.message));
// DETECTED is open: the two pieces of the sensor are apart
const door = { contact: "NOT_DETECTED", changedAt: new Date() };
const device = bridge.addDevice({ endpointId: "back-door", name: "Back Door", categories: ["CONTACT_SENSOR"] });
// proactivelyReported: Alexa takes ChangeReports for the capability
const contact = device.add(ContactSensor, { proactivelyReported: true });
device.state((s) => s.set(contact, "detectionState", door.contact, { timeOfSample: door.changedAt }).health("OK"));
async function changed(state) {
door.contact = state;
door.changedAt = new Date();
// What changed is set here. The rest of device.state(), the health, is the context of the report.
const result = await device.changeReport("PHYSICAL_INTERACTION", (s) => s
.set(contact, "detectionState", door.contact, { timeOfSample: door.changedAt }));
console.log(result.ok ? `the door reported ${state}` : `not reported: ${result.error.message}`);
}
process.stdin.on("data", () => changed(door.contact === "DETECTED" ? "NOT_DETECTED" : "DETECTED"));
bridge.connect();