Learning jQuery Deferreds. Taming Callback Hell with Deferreds and Promises (e-book) Katowice

Orchestrating asynchronous function calls in JavaScript often leads to callback hell, but there is a reliable way to avoid this painful state of affairs. With this concise and simple guide, you...ll learn how to use jQuery deferreds and promises, an elegant approach for managing asynchronous calls in both client and server applications. This book contains 18 examples that use deferreds to solve progressively challenging real-world programming problems, along with 75 stimulating puzzles (and their solutions) that will help you understand how and when to use deferreds. You...ll learn new tricks in a fun way, and become immersed in the practice of event-based programming. Understand the logic behind creating deferreds and returning promises Get a structured explanation of jQuery...s deferred API Delve into the dynamics of using deferreds Explore a broad collection of useful deferred recipes developed by the authors Gain hands-on experience by solving challenges that accompany each recipe Go deeper into deferreds: encounter novel abstractions and mind-bending use cases Spis treści: Learning jQuery Deferreds Preface About You Our Aims Challenges jQuery Deferreds Our JavaScript Coding Style, or Lack Thereof Conventions Used in This Book Using Code Examples Safari Books Online How to Contact Us Acknowledgments 1. Introduction Food for Thought Terminology: Deferreds and Promises Familiar Promises 2. The jQuery Deferred API Consuming Promises More Terminology: Resolve, Reject and Progress done fail always progress promise then state when Creating Deferreds Construction resolve and resolveWith reject and rejectWith notify and notifyWith Putting It All Together Deferred Dynamics Deprecated Promise Methods isRejected and isResolved pipe Changes in the jQuery Deferred API 3. Deferred Recipes A Replacement for the setTimeout Function Challenges Messaging in Chrome Extensions Challenges Accessing Chrome Local Storage Challenges Running Promise-Returning Functions One by One Challenges A Promise Pool with an emptyPromise Method Creating a Promise Pool Using the Promise Pool Challenges Displaying Google Maps Challenges Communicating with a Web Worker The Web Worker Code Creating a Web Worker Using It Summary Challenges Using Web Sockets The Web Socket Server The Web Socket Client Challenges Automatically Retrying Failing Deferred Calls Challenges Memoization Discussion Avoiding the Dogpile Effect Challenges Short-Term Memoization of In-Progress Function Calls createUser Is Not Idempotent Challenges Streaming Promise Events Delivering More Information Delegating the Event Stream To Be Continued Challenges Getting the First Result from a Set of Promises Which Promise Fired? A Fly in the Soup delegateEventStream Redux Challenges A Deferred Queue Challenges when2: An Improved jQuery.when Using when2 to Time Out a Single Promise Differences from $.when Challenges Timing Out Promises Challenges Controlling Your Own Destiny Challenges Deactivating a Promise Challenges 4. More Time in the Mental Gymnasium Do You Really Understand jQuery Deferreds? Promises/A+ Promises Are First-Class Objects for Function Calls Asynchronous Data Structures Advantages of Deferreds Difficulties with Deferreds Further Reading A. Hints for Selected Challenges A Replacement for the setTimeout Function Messaging in Chrome Extensions Accessing Chrome Local Storage Running Promise-Returning Functions One by One A Promise Pool with an emptyPromise Method Displaying Google Maps Communicating with a Web Worker Using Web Sockets Automatically Retrying Failing Deferred Calls Memoization Short-Term Memoization of In-Progress Function Calls Streaming Promise Events Getting the First Result from a Set of Promises A Deferred Queue when2: An Improved jQuery.when Timing Out Promises Controlling Your Own Destiny Deactivating a Promise B. The Promises/A+ Specification Terminology Requirements Promise States The then Method The Promise Resolution Procedure C. Converting an ArrayBuffer to Base 64 Colophon Copyright