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w/o callback
Presented by: Khoa Tran
Jan 7th 2014
Agenda
•

Why I don’t like callbacks

•

Is there good alternative to write async code?

•

Generator

•

Get rid of callbacks
Why I don’t like callbacks?
1. Lots of nesting functions

2. Variable scope confusion
3. Handle exceptions everywhere

Writing readable code is hard!!!
Is there good alternative?
•

Async

•

Fiber

•

Promise/Q

•

Co
Generator
•

“In computer science, a generator is a special routine that can be
used to control the iteration behaviour of a loop” - From wikipedia
Executor

Generator

…
next()

…
val1

process val1

yield val1

next()
process val2
…

…
val2

yield val2
Generator in node.js
•

Only supported in version 0.11.x and above. For
now, you have to build and install node.js from
Github.

•

In addition, execute code with --harmony flag.
Get rid of callbacks
Clone demo source at:
https://github.com/tvkkpt/jsmeetup-demo
What to do next
Join this open-source project:
https://github.com/visionmedia/co
About us
Author: Khoa Tran
Find me at: tvkkpt@gmail.com
Presentation made for JavaScript HCMC Meetup
You can find us at:
http://www.meetup.com/JavaScript-Ho-Chi-Minh-City/
https://www.facebook.com/JavaScriptHCMC?ref=hl
https://plus.google.com/communities/116105314977285194967
Thank you and HAPPY NEW
YEAR!

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Nodejs wo callback[Khoa Tran]

  • 1. w/o callback Presented by: Khoa Tran Jan 7th 2014
  • 2. Agenda • Why I don’t like callbacks • Is there good alternative to write async code? • Generator • Get rid of callbacks
  • 3. Why I don’t like callbacks? 1. Lots of nesting functions 2. Variable scope confusion 3. Handle exceptions everywhere Writing readable code is hard!!!
  • 4. Is there good alternative? • Async • Fiber • Promise/Q • Co
  • 5. Generator • “In computer science, a generator is a special routine that can be used to control the iteration behaviour of a loop” - From wikipedia Executor Generator … next() … val1 process val1 yield val1 next() process val2 … … val2 yield val2
  • 6. Generator in node.js • Only supported in version 0.11.x and above. For now, you have to build and install node.js from Github. • In addition, execute code with --harmony flag.
  • 7. Get rid of callbacks Clone demo source at: https://github.com/tvkkpt/jsmeetup-demo
  • 8. What to do next Join this open-source project: https://github.com/visionmedia/co
  • 9. About us Author: Khoa Tran Find me at: tvkkpt@gmail.com Presentation made for JavaScript HCMC Meetup You can find us at: http://www.meetup.com/JavaScript-Ho-Chi-Minh-City/ https://www.facebook.com/JavaScriptHCMC?ref=hl https://plus.google.com/communities/116105314977285194967
  • 10. Thank you and HAPPY NEW YEAR!