How to return callback data from cordova plugin angular/ionic

Question

im trying to implement a old cordova plugin who hasnt any native wrapper in ionic, i can load the plugin and console.log the data but i can't get the data to push it into an a global array, i get the error "accelerometerData is not defined" , this is the function im using to watch the plugin values:

// plugin cordova-plugin-device-motion-fast

declare var navigator: any;
accelerometerData: any[]; //<--- global variable

startAccelerometer(){
    var options = { frequency: 75 };  // Update every x seconds
    var watchID = navigator.accelerometer.watchAcceleration(
      function accelerometerSuccess(acceleration){
          let data = {
            x: 0,
            y: 0,
            z: 0,
            roll: 0,
            pitch: 0,
            yaw: 0,
            timestamp: 0
          }
          data.x = acceleration.x;
          data.y = acceleration.y;
          data.z = acceleration.z;
          data.roll = acceleration.roll;
          data.pitch = acceleration.pitch;
          data.yaw = acceleration.yaw;
          data.timestamp = acceleration.timestamp;
          console.log(data) //<--- i see the data here
          this.accelerometerData.push(data); // <--- null || undefined || error isn't defined
          
        },
      function accelerometerError(error){
           console.log(error)
      }, options);
  }
  
  saveTheData(){ <--- save the data to api
   const data = {
   Accelerometer:  this.accelerometerData // <--- null || undefined || error isn't defined
   }
   this.saveToApi(data).subscribe()....
  }

if i try to console.log this.accelerometerData or try to access in any other functions the variable is null or undefined...

thanks in advance.

Answer 1

I found myself a solution wrapping the cordova callback into a promise, then use a interval to watch the data per x ms, finally define a timeout to clear the interval

// wrap the plugin
startAccelerometer(){
    return new Promise((resolveCallback, rejectCallback) =>{
     new Promise((resolve, reject) =>{
      navigator.accelerometer.watchAcceleration(resolve,reject);
     }).then((acceleration) => {
        resolveCallback(acceleration);
     }).catch((error) =>{
       rejectCallback(error);
     });
    });
  }
  
 // usage
getData(){
  const frequency =  75;
  const duration = 30000;
  var watchID = setInterval(() => this.getData(),frequency);
  this.startAccelerometer().then((accelerometer) =>{
    console.log(accelerometer);
  });
  setTimeout(() => clearInterval(watchID),duration);
}
   
   //call the getData()
   this.getData();