Exercise 37: Sequencing HTTP requests with Observable: async await version

37-http-async-await.js

// this is an implementation of exercise 37 of
// http://reactivex.io/learnrx/
// to compare with the Observable implementation
// i assume that getJSON returns a Promise instead of an Observable...

function load(){
    return new Promise(function(resolve,reject){
         window.onload = resolve;
    });
}

function(window, getJSON, showMovieLists, showError) {
  async function processMovieLists(){
    try{
      const abTestInformation = await getJSON("http://api-global.netflix.com/abTestInformation");
    
      const results = await Promise.all([
        getJSON("http://api-global.netflix.com/" + abTestInformation.urlPrefix + "/config"),
        getJSON("http://api-global.netflix.com/" + abTestInformation.urlPrefix + "/movieLists"),
      ]);

      const config = results[0];
      const movieListsMessage = results[1];

      const copyOfMovieLists = Object.create(movieListsMessage.list);

      if(config.showInstantQueue){
        const queueMessage = await getJSON("http://api-global.netflix.com/" + abTestInformation.urlPrefix + "/queue");

        const queue = queueMessage.list;
        copyOfMovieLists.push(queue);
      }
      

      await load();
      showMovieLists(copyOfMovieLists);
    }
    catch(err){
      showError(err);
    }
  }

  processMovieLists();
}