mirror of
https://github.com/jbranchaud/til
synced 2026-01-03 15:18:01 +00:00
27 lines
1.2 KiB
Markdown
27 lines
1.2 KiB
Markdown
# Throttling A Function Call
|
|
|
|
Imagine you have a JavaScript function that makes a request to your server.
|
|
Perhaps it is sending user input from a `textarea` to be processed by the
|
|
server. You may want to wrap this function in a keyboard event listener so
|
|
that you are sure to react immediately to any user input. However, as the
|
|
user starts typing away into this text area you may find that way to many
|
|
requests are being fired off to the server. The request needs to be
|
|
*throttled*.
|
|
|
|
You can roll your own approach to sufficiently intermittent server calls.
|
|
Though, it turns out that [underscore.js](http://underscorejs.org/) comes
|
|
with two functions out of the box for this kind of behavior.
|
|
|
|
- [`throttle`](http://underscorejs.org/#throttle) will give you a function
|
|
that wraps your function in a way that essentially rate-limits it to being
|
|
called at most once every `N` milliseconds.
|
|
|
|
- [`debounce`](http://underscorejs.org/#debounce), on the other hand, will
|
|
give you a function that only calls your function once `N` milliseconds
|
|
has passed since it was last called.
|
|
|
|
These are two subtly different approaches to making sure a function gets
|
|
call, just not too often.
|
|
|
|
h/t [Jake Worth](https://twitter.com/jwworth)
|