Handling asynchronous: yesterday, today, tomorrow, and after

ParisJS #44

CALLBACKS1

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We get the data after 1000ms

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What if I need to chain callbacks?

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Wtf…

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PROMISES2

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ES6 Promises, A+ implementation

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ES6 Promises, how to use them

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Back to our example: we get the data after 1000ms

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Getting better! But still not perfect

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Should we start using ES6 Promises?Yes with a polyfill (eg: Babel)

GENERATORS3

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The function* declaration defines a generator functionWhich returns a Generator object

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The body is not executed. When asked to,the code is executed until the first ‘yield’ expression

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How to use a generator function by callinggenerator.next()

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Keep calling .next() till `done` is true

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Back to our example

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Wow! Looks great!Does it work? No

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Wrapped inside a custom `async` function, it worksAsynchronous code like if it was synchronous

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The async function is trivial to implementOr you can use the Q library (Q.spawn)

Or the co library

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Looking great! Want better?

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Should we use it yet?Why not.

- Custom async implementation- ES6 to ES5 with BabelJS- BabelJS polyfill for Promises

ES7ASYNC / AWAIT4

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ES7 native async / await`getData` returns a Promise

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Now that’s awesomeAsynchronous code like if it was synchronous

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Should we use it yet?No.

Or just for fun,it’s too early and things are still moving.

(BabelJS in experimental mode)

SUMMARY5

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Yesterday: callbacks

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Today: Promises

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Tomorrow: Generators?

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The day after tomorrow: ES7 async / await

THANK YOU

@gmajoulet