lwcapipromise.js

import { LightningElement, track} from 'lwc';

// importing apex class to make callout
import getSomething from '@salesforce/apex/MyAPIstuff.retrieve';
import startRequest from '@salesforce/apexContinuation/MyAPIstuff.startRequest';

export default class MyAPIstuff extends LightningElement {
    @track token;
    @track imperativeContinuation = {};


    // Imperative Call
    callContinuation() {
        startRequest()
            .then(result => {
                this.imperativeContinuation = result;
            })
            .catch(error => {
                this.imperativeContinuation = error;
            }
        );
    }

    get formattedImperativeResult() {
        //result = JSON.stringify(this.imperativeContinuation);
        //console.log('formattedImperativeResult', result);
        return JSON.stringify(this.imperativeContinuation);
    }
    

    handleConnection() {
        alert('Working...');
        var t0 = performance.now();
        getSomething()
        .then(data => {
            this.promiseFunc(data);
        })
        .catch(error => {
            alert('EXCEPTION!!!');
            console.log('error ====> ', error);
        })
        
    }

    promiseFunc(data) {
        console.log('promiseFunc', data);
        return new Promise((resolve, reject) => {
            setTimeout(() => {
                console.log('resolving...');
                var t1 = performance.now();
                // console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
                console.log('DONE');
                console.log('The Data: ', JSON.parse(data));
                //this poiint;
                data.result.forEach(function(elem){
                    console.log(elem.name)
                });
                resolve(data);
            }, 20000);
        });
    }
}