Javascript。 在前端安全使用 async 和 await 吗？

Question

I'm building a web application using angular. I know that with ES6 i can use the async/wait, i found this guide how to use them transforming an Observable to Promise. https://labs.encoded.io/2016/12/08/asyncawait-with-angular/ But it is safe? the browser is single thread, and i'm little bit afraid to use it thinking that it block all the UI. Can someone give more information about it? Thanks

Answer 1

It's not going to block the thread; at least not more than writing callback-based code . That's essentially it's whole point; It allows writing asynchronous code as-if it was synchronous; making the flow far easier to reason about.

It is more or less syntactic sugar over on top of generators and promises , which are non-blocking mechanisms for managing asynchronous actions.

That being said, they're not magic; the same mistakes that can make callback-based code block the thread can also block when written in async / await .

Answer 2

Async/await is experimental and part of ES7 . Server-side, NodeJS supports it (latest versions) but in a browser, it will almost certainly not be supported. Use good old Promises/Ajax instead.

the browser is single thread, and i'm little bit afraid to use it thinking that it block all the UI

Async/await / Promises / Ajax won't block the UI, by definition, because they are asynchronous.