Having nested promises and returning them in route won't update the route model and the template using that model

Question

in my route model i need to send two requests (previous and latest) and on the response i grab their ids to send two other requests(baslineCpature and currentcapture). when i got the responses of both requests, i need to send two other requests(fiberHealthData, wavelengthsPerSectionData). ember model should return (baslineCpature,currentcapture, fiberHealthData, wavelengthsPerSectionData ). one issue i have here is that i want to update my template as soon as i get response for baslineCpature and currentcapture.

Here is my code. I appreciate if someone can tell me what i am doing wrong.

model: function (params,transition) {

  var promiseA=null;
  var promiseB=null;
  var promiseA1=null;
  var promiseB1=null;

  promiseA1 = Ember.RSVP.hash({
    latest:this.store.findAll('latest'),
    previous: this.store.findAll('previous'),
  });

  promiseA= promiseA1.then((promiseAResolved) => {
    return Ember.RSVP.hash({
      baselineCapture:self.store.find('capture', promiseAResolved.previous.get('firstObject.id')),
      currentCapture: self.store.find('capture', promiseAResolved.latest.get('firstObject.id')),
    });
  });

  promiseB= promiseA.then((promiseAResolved) => {
    baselineId =  promiseAResolved.baselineCapture.id;
    currentId =  promiseAResolved.currentCapture.id;

    return Ember.RSVP.hash({
      fiberHealthData:self.store.findAll('fiber-health',{ adapterOptions: {current: currentId, baseline: baselineId}}),
      wavelengthsPerSectionData:self.store.findAll('wavelengths-per-section',{ adapterOptions: {current: currentId, baseline: baselineId}} )
    });
  });

//this should be retun of my model
  return Ember.RSVP.hash({
    baselineCapture:promiseA.baselineCapture,
    currentCapture:promiseA.currentCapture,
     fiberHealthData:promiseB.fiberHealthData,
    wavelengthsPerSectionData:promiseB.wavelengthsPerSectionData,
  });
}

Answer 1

Okay, first this is what you should do:

const {hash} = Ember.RSVP;

return hash({
    latest:this.store.findAll('latest'),
    previous: this.store.findAll('previous'),
}).then(({latest, previous}) => hash({
    baselineCapture:self.store.find('capture', previous.get('firstObject.id')),
    currentCapture: self.store.find('capture', latest.get('firstObject.id')),
})).then(({baselineCapture, currentCapture}) => {
    let current = currentCapture.id;
    let baseline = baselineCapture.id;
    return hash({
        currentCapture,
        baselineCapture,
        fiberHealthData:self.store.findAll('fiber-health',{
            adapterOptions: {current, baseline}
        }),
        wavelengthsPerSectionData:self.store.findAll('wavelengths-per-section', {
            adapterOptions: {current, baseline}
        }),
    });
});

Use the ES6 features like destructing. Its very useful for these use cases!

You need to understand how promise chaining works! Have you read Promises/A+? It's one of the best specification I've ever read. Read it!

What you did wrong is using promiseA.baselineCapture. You can't access a promise without resolving it with then.

Answer 2

here is what i got to work:

        return new Ember.RSVP.Promise(resolve => {
          Ember.RSVP.hash({
            latest: this.store.findAll('latest'),
            previous: this.store.findAll('previous'),
          }).then((promiseA1Resolved) => {
            Ember.RSVP.hash({
              baselineCapture:self.store.find('capture', promiseA1Resolved.previous.get('firstObject.id')),
              currentCapture: self.store.find('capture', promiseA1Resolved.latest.get('firstObject.id')),
            }).then((promiseAResolved) => {
              self.updateContext(promiseAResolved,self);
              resolve({
                baselineCapture: promiseAResolved.baselineCapture,
                currentCapture:  promiseAResolved.currentCapture,
                fiberHealthData:self.store.findAll('fiber-health',{ adapterOptions: {current: self.get('contextService._currentId'), baseline:self.get('contextService._baselineId') }}),
                wavelengthsPerSectionData:self.store.findAll('wavelengths-per-section',{ adapterOptions: {current: self.get('contextService._currentId'), baseline: self.get('contextService._baselineId')}} )
              });

            });
          });
        });