Chaining and Composing Promises
Learn to chain multiple asynchronous operations using .then() and .pipe(), and compose complex workflows by waiting for multiple Promises to complete with $.when().
Sequence Async Operations
In web development, we often need to perform asynchronous tasks (like fetching data) in a specific order. Chaining promises allows us to do this cleanly.
Instead of nesting callbacks, which can lead to 'callback hell', we can link operations sequentially, making our code much easier to read and maintain.
Chaining with .then()
The .then() method is fundamental for chaining. When a Deferred (or Promise) resolves, its .then() callback is executed. What this callback returns can then be used by the next .then() in the chain.
If the callback returns a new Deferred, the chain waits for that new Deferred to resolve before proceeding.
All lessons in this course
- Understanding Deferred Objects
- Chaining and Composing Promises
- Handling Multiple Asynchronous Tasks