generic-polling-pulse

Promise based generic polling.

Table of Contents

• generic-polling-pulse
  • Table of Contents
  • Installing
  • Usage
  • Dictionary - Methods

Installing

Using npm:

$ npm install generic-polling-pulse

Usage

Basic usage (async):

const { Polling } =  require('generic-polling-pulse'); 
//Or
import { Polling } from  "generic-polling-pulse"; //ES6

const poll = new  Polling();

async function doSomething() {
	const run = await poll.run({
		waitForFn: () => 'Basic command', 
		delay:1000,
		retry:5,
	})
}
// Basic poll is waiting for truthy response from waitForFn callback.
// poll.run will return the wanted result from the waitfor function.

Basic usage (then):

const { Polling } =  require('generic-polling-pulse'); 
//Or
import { Polling } from  "generic-polling-pulse"; //ES6

const poll = new  Polling();

const run = poll.run({
	waitForFn: () => 'Basic command', 
	delay:1000,
	retry:5,
});
run.then((res) => {
	console.log(res)
});
// Basic poll is waiting for truthy response from waitForFn callback.
// poll.run will return the wanted result from the waitfor function.

Basic usage with exponential backoff:

import { Polling } from  "generic-polling-pulse";
  
const poll = new  Polling({exponential:  true});

const waitFor = () => {
	Waiting for answer...
}
  
async function doSomething() {
	const run = await poll.run({
		waitForFn: waitFor, 
		delay: 2, // Delay in ms
		retry: 10,
		// We have added log function if we want to debug and more info.
		logFn: ({delayTime}) =>  console.log('delay: '+ delayTime)
	})
}

Advanced examples:

A. The use of custom validations:

import { Polling } from  "generic-polling-pulse";

const poll = new  Polling();

const waitFor = () => {
	// Waiting for answer... can return 200 | 201 | 404 | 500
	// first return 404
	// second return 404
	// third return 200;
}
  
// We can use custom validate callback function to validate our waitForFn response.
// We are looking for status 200;
// The param - is actuall response response from waitForFn callback.
const customValid = (param: null | number) => {
	// We are looking for 200 response from waitFor callback.
   if(param === 200) return  200;
}

async function doSomething() {
	const result = await poll.run({
	    waitForFn: waitFor,
	    delay:100,
	    retry:11,
	    validateFn: customValid
	})
}

B. Usage of types

import { Polling } from  "generic-polling-pulse";
    
const  poll = new  Polling();
 
async function doSomething() {
	const result = await poll.run<{name: string, last: string}>({
		waitForFn:  waitFor,
		delay:100,
		retry:11,
		// We can use custom validate callback function to validate our waitForFn response.
		validateFn: (obj) => {if(obj && obj.name && obj.last) return  true}
	})
}

C. WaitFor usage of parameters:

import { Polling } from  "generic-polling-pulse";
 
const  poll = new  Polling();

const waitForWithParams = async (token: string) => {
	... fetch(url) logic waits untill data recived;
	return  'My name is: ' + ' ' + name + ' ' + lastName;
}
async function doSomething() {
	const  result = await poll.run<{name: string, last: string}>({
		waitForFn: waitForWithParams,
		delay:100, // delay in ms
		retry:11, // Number of retries
		params: ['12345678a'] // Params used for waitForFn
	})
}

Dictionary - Methods

 run<T>({waitForFn, validateFn, logFn, delay, retry, params, power}): Promise<T>

CallBacks	explanation
waitForFn	WaitFor Function is the function you want to run poll on. The default validation process checks if the WaitFor has a truthy response. For custom validation please use "validateFn".
validateFn	Validate Function accepts waitForFunction's result. The default validation checks if the response is truthy or not. You can use this function to write your own custom logic.
logFn	logger accepts callback function that returns some logging information. {result, retry, delayTime}.
Params	--
delay	Sets a delay in ms.
retry	Sets the number of maximum polling runs.
params	Sets a parameters that will be called by the waitForFn method.
power	Sets the power $X^{Y}$. It is possible to change the initial default power
retryErrorMessage	Sets custom retry error message.

---

 stop():{ status: string } // in case you want to stop polling manually. (abort/cancel)