promisify

[schnippe]

Hi Sandeep,

would you accept a pull request for compatibility to promises and harmony generators? This would help out of the callback hell and look pretty nice. Harmony Generators are supported in node 0.12 I am thinking about making a Promise Wrapper around the node-sensortag API or forking it. I will retain node 0.10 compatibility.

Test.js could look like this or even shorter:

var Promise = require('bluebird');
var SensorTag = require('sensortag')

Promise.coroutine(function* () {
  var sensorTag = yield SensorTag.discover()

  sensorTag.on('disconnect', function () {
    console.log('disconnected!');
  });

  console.log('connecting...');
  yield sensorTag.connect();

  console.log('discoverServicesAndCharacteristics');
  yield sensorTag.discoverServicesAndCharacteristics();

  console.log('readSystemId');
  console.log('\tsystem id = ' + yield sensorTag.readSystemId());

  console.log('readSerialNumber');
  console.log('\tserial number = ' + yield sensorTag.readSerialNumber());

  console.log('readFirmwareRevision');
  console.log('\tfirmware revision = ' + yield sensorTag.readFirmwareRevision());

  console.log('readHardwareRevision');
  console.log('\thardware revision = ' + yield sensorTag.readHardwareRevision());

  console.log('readSoftwareRevision');
  console.log('\tsoftware revision = ' + yield sensorTag.readHardwareRevision)();

  console.log('readManufacturerName');
  console.log('\tmanufacturer name = ' + yield sensorTag.readManufacturerName());

  console.log('enableIrTemperature');
  yield sensorTag.enableIrTemperature()
  yield Promise.delay(2000);
  console.log('readIrTemperature');
  var irTemperature = yield sensorTag.readIrTemperature();
  console.log('\tobject temperature = %d °C', irTemperature.objectTemperature.toFixed(1));
  console.log('\tambient temperature = %d °C', irTemperature.ambientTemperature.toFixed(1));

  console.log('disableAccelerometer');
  yield sensorTag.disableAccelerometer();
  console.log('enableAccelerometer');
  yield sensorTag.enableAccelerometer();
  yield Promise.delay(2000);
  console.log('readAccelerometer');
  var accelerometer = yield sensorTag.readAccelerometer();
  console.log('\tx = %d G', accelerometer.x.toFixed(1));
  console.log('\ty = %d G', accelerometer.y.toFixed(1));
  console.log('\tz = %d G', accelerometer.z.toFixed(1));
  console.log('disableAccelerometer');
  yield sensorTag.disableAccelerometer();

  console.log('enableHumidity');
  yield sensorTag.enableHumidity();
  yield Promise.delay(2000);
  console.log('readHumidity');
  var humidity = yield sensorTag.readHumidity();
  console.log('\ttemperature = %d °C', humidity.temperature.toFixed(1));
  console.log('\thumidity = %d %', humidity.humidity.toFixed(1));
  console.log('disableHumidity');
  yield sensorTag.disableHumidity();

  console.log('enableMagnetometer');
  sensorTag.enableMagnetometer();
  yield Promise.delay(2000);
  console.log('readMagnetometer');
  var magnetometer = yield sensorTag.readMagnetometer();
  console.log('\tx = %d μT', magnetometer.x.toFixed(1));
  console.log('\ty = %d μT', magnetometer.y.toFixed(1));
  console.log('\tz = %d μT', magnetometer.z.toFixed(1));
  console.log('disableMagnetometer');
  yield sensorTag.disableMagnetometer();

  console.log('enableBarometricPressure');
  yield sensorTag.enableBarometricPressure();
  yield Promise.delay(2000);
  console.log('readBarometricPressure');
  console.log('\tpressure = %d mBar',
    (yield sensorTag.readBarometricPressure()).toFixed(1));
  console.log('disableBarometricPressure');
  yield sensorTag.disableBarometricPressure();

  console.log('enableGyroscope');
  yield sensorTag.enableGyroscope();
  yield Promise.delay(2000);
  console.log('readGyroscope');
  var gyroscope = yield sensorTag.readGyroscope();
  console.log('\tx = %d °/s', gyroscope.x.toFixed(1));
  console.log('\ty = %d °/s', gyroscope.y.toFixed(1));
  console.log('\tz = %d °/s', gyroscope.z.toFixed(1));
  console.log('disableGyroscope');
  yield sensorTag.disableGyroscope();

  console.log('readTestData');
  console.log('\tdata = ' + yield sensorTag.readTestData());

  console.log('readTestConfiguration');
  console.log('\tconfiguration = ' + yield sensorTag.readTestConfiguration());

  console.log('readSimpleRead, press both buttons on your SensorTag');

  yield new Promise(function (resolve, reject) {
    sensorTag.on('simpleKeyChange', function (left, right) {
      console.log('left: ' + left);
      console.log('right: ' + right);
      if (left && right) {
        resolve(true);
      }
    });
  });

  return sensorTag;
})().
  then(function (sensorTag) {
    console.log('done testing ' + sensorTag.uuid)
  }, function (err) {
    console.error(err.stack)
  })

[sandeepmistry]

@schnippe would this force users into using promises? If so, creating a "promisified" version that wraps the currently library makes more sense.

[schnippe]

@sandeepmistry No, it would not force users into using promises. But it would enforce using a single api style like

SensorTag.discover (param1, param2, callback) // with callback(error, result1, result2)   

It would possibly mean maintaing a part of the api-signature twice, too.

Are you interested?

[sandeepmistry]

@schnippe error parameters for callbacks have been added to master.

[sandeepmistry]

@schnippe any progress on this, now that callback have error parameters?

[sandeepmistry]

Closing for now due to lack of activity/interest.