streamich / set-harmonic-interval

one timer for all setInterval() with identical ms delay

set-harmonic-interval

Works similar to setInterval, but calls all callbacks scheduled using setHarmonicInterval all at once, which have same delay in milliseconds.

Install

npm install set-harmonic-interval

Usage

In below example 1 and 2 will always be printed together every second.

const { setHarmonicInterval, clearHarmonicInterval } = require('set-harmonic-interval');

setHarmonicInterval(() => console.log(1), 1000);
setTimeout(() => {
  setHarmonicInterval(() => console.log(2), 1000);
}, 500);

License

Unlicense — public domain.

set-harmonic-interval's Issues

Feature Request: Allow consumer to control bucket ids

All timers are grouped into "buckets" that are identified by the ms parameter. Using the ms parameter as a bucket identifier can have undesired consequences.

My suggestion: add an extra id parameter and use it as bucket identifier instead of ms parameter.
Furthermore, I think this parameter should be required (it should not default to the value of ms).
Which would be a non-backwards-compatible change.

---

Since, as I understand, set-harmonic-interval was developed to be used by react-use, let me use react-use as an example.

Suppose you want to have 2 sets of components - numerous instances of <X/> and numerous instances of <Y/> - and:

• you want both <X/> and <Y/> to update after the same interval (same ms parameter value)
• but you don't necessarily want instances of X to update when instances of Y update

This is impossible with the current implementation, because buckets are created per ms parameter.

Hopefully the above explanation is sufficient but consider this example for completeness: https://codesandbox.io/s/tender-kepler-9r1j1?file=/src/App.js
The stoplights will harmonically change the light every 5 seconds.
The triggers will harmonically flash every 5 seconds as well.
But triggers will not start flashing until you press any of them.
And if it just so happens, that you push the trigger 100ms before the stoplights are about to change, the trigger indicators will be on only for that 100ms, while I'd expect them to be on for the first 5 seconds after triggering.