Asynchronous programming in Dart

Transcript

2. CONTENTS C O N T E N T S Isolates and Event Loop 1 Futures 2 Async / Await 3 Streams 4
3. 01 Isolates and Event Loop
6. An event loop’s job is to take an item from the event queue and handle it, repeating these two steps for as long as the queue has items.
7. 02 Futures
8. Future - a promise that you'll get some value or accomplish a task in future Completes with a value or may return an error States: Uncompleted, Success, Error
10. Events that execute asyncronously Future.value() Future.delayed(Duration) Future.error() Future.wait([])
11. • then() - executed when the Future completes with a value • catchError() - executed when the Future completes with an error • whenComplete() - executed when the Future completes; whether with an error or value
12. Demo Time!
13. 03 Streams
14. Streams - a source of asynchronous events (elements) delivered sequentially Used to get asynchronous sequence of data like from APIs, reading from files. Once all data elements have been emitted, a special event signalling the stream is done will notify any listeners that there is no more.
15. Single-subscription streams - only one listener at a time Broadcast streams - Multiple listeners at a time *Without subscribing/listening, to a stream, it's just an object with potential values
16. Demo Time!
17. 04 Async & Await
18. async/await keywords - syntactic sugar to make it easy to use Futures and Streams Just alternative syntax for handling Futures and Streams Your code ends up looking like syncronous code
19. Demo Time!
20. THANK YOU