rx-queue

RX-QUEUE

Easy to Use ReactiveX Queue that Supports Delay/DelayExecutor/Throttle/Debounce Features Powered by RxJS.

Picture Credit: Queues in JavaScript

CLASSES

1. RxQueue
2. DelayQueue
3. ThrottleQueue
4. DebounceQueue
5. DelayQueueExecutor

RxQueue

RxQueue is the base class of all other queues. It extends from RxJS Subject.

Example:

import { RxQueue } from 'rx-queue'

const queue = new RxQueue()
queue.next(1)
queue.next(2)
queue.next(3)

queue.subscribe(console.log)
// Output: 1
// Output: 2
// Output: 3

DelayQueue

DelayQueue passes all the items and add delays between items.

Picture Credit: ReactiveX Single Operator Delay

Practical examples of DelayQueue:

1. We are calling a HTTP API which can only be called no more than ten times per second, or it will throw a 500 error.

Example:

import { DelayQueue } from 'rx-queue'

const delay = new DelayQueue(500)  // set delay period time to 500 milliseconds
delay.subscribe(console.log)

delay.next(1)
delay.next(2)
delay.next(3)

// Output: 1
// Paused 500 millisecond...
// Output: 2
// Paused 500 millisecond...
// Output: 3

ThrottleQueue

ThrottleQueue passes one item and then drop all the following items in a period of time.

Picture Credit: ReactiveX Observable Throttle

By using throttle, we don't allow to our queue to pass more than once every X milliseconds.

Practical examples of ThrottleQueue:

1. User is typing text in a textarea. We want to call auto-save function when user is typing, and want it only run at most once every five minutes.

Example:

import { ThrottleQueue } from 'rx-queue'

const throttle = new ThrottleQueue(500)  // set period time to 500 milliseconds
throttle.subscribe(console.log)

throttle.next(1)
throttle.next(2)
throttle.next(3)

// Output: 1

DebounceQueue

DebounceQueue drops a item if there's another one comes in a period of time.

Picture Credit: ReactiveX Observable Debounce

The Debounce technique allow us to deal with multiple sequential items in a time period to only keep the last one.

Debouncing enforces that no more items will be passed again until a certain amount of time has passed without any new items coming.

Practical examples of DebounceQueue:

1. User is typing text in a search box. We want to make an auto-complete function call only after the user stop typing for 500 milliseconds.

Example:

import { DebounceQueue } from 'rx-queue'

const debounce = new DebounceQueue(500)  // set period time to 500 milliseconds
debounce.subscribe(console.log)

debounce.next(1)
debounce.next(2)
debounce.next(3)

// Paused 500 millisecond...
// Output: 3

DelayQueueExecutor

DelayQueueExecutor calls functions one by one with a delay time period between calls.

Picture Credit: ReactiveX Single Operator Delay

Practical examples of DelayQueueExecutor:

1. We are calling a HTTP API which can only be called no more than ten times per second, or it will throw a 500 error.

Example:

import { DelayQueueExecutor } from 'rx-queue'

const delay = new DelayQueueExecutor(500)  // set delay period time to 500 milliseconds

delay.execute(() => console.log(1))
delay.execute(() => console.log(2))
delay.execute(() => console.log(3))

// Output: 1
// Paused 500 millisecond...
// Output: 2
// Paused 500 millisecond...
// Output: 3

SEE ALSO

• Writing Marble Tests

CHANGELOG

v0.8 - Mar 2019

1. Fix typo of ISSUE #40: rename DelayQueueExector to DelayQueueExecutor

v0.6 - Sep 2018

1. fix exception bug in browser(ie. Angular)

v0.4 - May 2018

1. Upgrade to RxJS 6
2. Moved CI from Travis-ci.org to Travis-ci.com

v0.2 - Oct 30, 2017

1. Support: DelayQueue, ThrottleQueue, DebounceQueue, DelayQueueExecutor.
2. first version

AUTHOR

Huan LI (李卓桓) <[e-mail]>

COPYRIGHT & LICENSE

• Code & Docs © 2017-2018 Huan LI <[e-mail]>
• Code released under the Apache-2.0 License
• Docs released under Creative Commons