Instance properties

authenticatedSignedWrites Read only

Returns a boolean that is true if signed writing to the characteristic value is permitted.

broadcast Read only

Returns a boolean that is true if the broadcast of the characteristic value is permitted using the Server Characteristic Configuration Descriptor.

indicate Read only

Returns a boolean that is true if indications of the characteristic value with acknowledgement is permitted.

notify Read only

Returns a boolean that is true if notifications of the characteristic value without acknowledgement is permitted.

read Read only

Returns a boolean that is true if the reading of the characteristic value is permitted.

reliableWrite Read only

Returns a boolean that is true if reliable writes to the characteristic is permitted.

writableAuxiliaries Read only

Returns a boolean that is true if reliable writes to the characteristic descriptor is permitted.

write Read only

Returns a boolean that is true if the writing to the characteristic with response is permitted.

writeWithoutResponse Read only

Returns a boolean that is true if the writing to the characteristic without response is permitted.

Examples

The following example shows how tell if a GATT characteristic supports value change notifications.

let device = await navigator.bluetooth.requestDevice({
  filters: [{ services: ["heart_rate"] }],
});
let gatt = await device.gatt.connect();
let service = await gatt.getPrimaryService("heart_rate");
let characteristic = await service.getCharacteristic("heart_rate_measurement");
if (characteristic.properties.notify) {
  characteristic.addEventListener(
    "characteristicvaluechanged",
    async (event) => {
      console.log(`Received heart rate measurement: ${event.target.value}`);
    },
  );
  await characteristic.startNotifications();
}

Specifications

Browser compatibility