Book Image

The TypeScript Workshop

By : Ben Grynhaus, Jordan Hudgens, Rayon Hunte, Matt Morgan, Vekoslav Stefanovski
5 (1)
Book Image

The TypeScript Workshop

5 (1)
By: Ben Grynhaus, Jordan Hudgens, Rayon Hunte, Matt Morgan, Vekoslav Stefanovski

Overview of this book

By learning TypeScript, you can start writing cleaner, more readable code that’s easier to understand and less likely to contain bugs. What’s not to like? It’s certainly an appealing prospect, but learning a new language can be challenging, and it’s not always easy to know where to begin. This book is the perfect place to start. It provides the ideal platform for JavaScript programmers to practice writing eloquent, productive TypeScript code. Unlike many theory-heavy books, The TypeScript Workshop balances clear explanations with opportunities for hands-on practice. You’ll quickly be up and running building functional websites, without having to wade through pages and pages of history and dull, dry fluff. Guided exercises clearly demonstrate how key concepts are used in the real world, and each chapter is rounded off with an activity that challenges you to apply your new knowledge in the context of a realistic scenario. Whether you’re a hobbyist eager to get cracking on your next project, or a professional developer looking to unlock your next promotion, pick up a copy and make a start! Whatever your motivation, by the end of this book, you’ll have the confidence and understanding to make it happen with TypeScript.
Table of Contents (16 chapters)
Preface

10. Event Loop and Asynchronous Behavior

Activity 10.01: Movie Browser Using XHR and Callbacks

Solution:

  1. In the script.ts file, locate the search function and verify that it takes a single string parameter and that its body is empty.
  2. Construct a new XMLHttpRequest object:
        const xhr = new XMLHttpRequest();
  3. Construct a new string for the search result URL using the getSearchUrl method:
        const url = getSearchUrl(value);
  4. Call the open and send methods of the xhr object:
        xhr.open('GET', url);    xhr.send();
  5. Add an event handler for the xhr object's onload event. Take the response and parse it as a JSON object. Store the result in a variable of the SearchResultApi interface. This data will have the results of our search in a results field. If we get no results, this means that our search failed:
        xhr.onload = function() {  ...