Ember promise - accessing value - use the RSVP method?

Question

I am working on an Ember application..

Its using Ember.inject.service modules -- and its not resolving the promise - not providing just the string I need from it

I have a service that looks like this

let downloadMethod = this.get('service1')
  .fetch(id)
  .then(res => {
    console.log("res", res.agenda.method.value)
    res.agenda.method.value
 });

console.log("downloadMethod", downloadMethod);

when I try to access this -- the console log for downloadmethod shows a promise -- but inside the then -- res comes out as the string value I need.

how do I get the value out of the "downloadMethod" -- it shows as a promise, instead of a string result?

Do I need to wrap this around an Ember.RSVP.hash?

Possible duplicate of [How do I return the response from an asynchronous call?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — Muhammad Usman, Apr 24 '18 at 16:02
it just displays a promise - as opposed to the value I need to get from the promise — The Old County, Apr 24 '18 at 16:03
how do I get the value out of the "downloadMethod" -- it shows as a promise, instead of a string result — The Old County, Apr 24 '18 at 16:05
This is how asynchronous programming works. See the duplicate. — rmlan, Apr 24 '18 at 16:05
I've explained several times -- downloadMethod is console logging out as a promise instead of a string - why — The Old County, Apr 24 '18 at 16:06
You need to read more about asynchronous programming and Promises. — rmlan, Apr 24 '18 at 16:53
@rmlan - I do know about asynchronous programming and Promise. It would be good if you could provide actual Ember injection based service examples — The Old County, Apr 24 '18 at 18:14

Paul · Answer 1 · 2018-04-24T19:53:54.850

2

The console.log("downloadMethod", downloadMethod) is called before the promise finishes, so you don't have the string value yet. You just have the unresolved promise.

So you need to save the value inside the then function. Below is some code to show what that looks like if this was inside an Ember Component

import Component from '@ember/component';
import { inject as service } from '@ember/service';

export default Component.extend({
  service1: service(),
  fetchedValue: null,

  actions: {
    someAction() {
      this.get('service1')
        .fetch(id)
        .then(res => {
          this.set('fetchedValue', res.agenda.method.value);
        });
    }
  }
})

This code is Ember version 2.16 and above

edited Apr 24 '18 at 19:53

answered Apr 24 '18 at 17:02

Paul

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That's a possible way -- but I do need to obtain the fetchedvalue at the level of a call to action. – The Old County Apr 24 '18 at 18:17
@TheOldCounty I updated my code example to fetch the data in an action. – Paul Apr 24 '18 at 19:54
the problem is - this is only part of a very very complicated pre-built Ember application. I'm already going to have to hijack and prevent an action to run this promise -- and I'm more of a react js dev – The Old County Apr 24 '18 at 23:13
@Gaurav - I understand that - but the code is written in Ember. It appears several services are merged using RSVP – The Old County Apr 25 '18 at 08:14

score -1 · Accepted Answer · answered Apr 25 '18 at 11:37

-1

The actual solution to this was to create a return RSVP.hash in the model parent.

model () {
    return RSVP.hash({
      deliveryMethod: this.get('service1').fetch(this.get('service2').id).then(res => {
         return res.agenda.method.value;
      })
    });
},

answered Apr 25 '18 at 11:37

The Old County

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service2 was not mentioned in the original example code. Could you clean up the question so we can understand this answer? – Gaurav Apr 25 '18 at 19:16
@Gaurav it doesn't matter - this service2 was used to get an id - so really just an id is returned at that juncture -- "this.get('service2').id" -- its used to fetch a record - so what you have is a chain. I don't really know how else to explain it - given you have the exact code - and the problem throughout -- whenever I tried to access "downloadMethod" it would return a promise -- then just a fetched string. --- its a giant 50-100 file Ember project -- and so not even Paul's answer satisfies the issue for me. – The Old County Apr 25 '18 at 21:54

Ember promise - accessing value - use the RSVP method?

2 Answers2