akirattii/mildloop

A simple helper library for async function's loop execution.

mildloop

A simple helper library for async function's loop execution. It allows you to execute your async function logic repeatedly, passing any parameter to every executions of a function.

Install

npm install --save mildloop

Basic Usage

const mildloop = require("mildloop");

// mildloop options:
var options = {
  suspend: true, // suspend if any error occurred. Defaults to false.
}

var params = [...]; // Array of param which is pass to each function

// Let's use mildloop!
mildloop({ params, fn: asyncfn, options }, (errors, results, status) => {
  console.log("status:", status);
  console.log("errors:", errors);
  console.log("results:", results);
});

Options

Option	Type	Detail	Default
suspend	Boolean	If set true, when any error occurred in the middle of loop, breaks execution loop.	false
interval	Number	Milliseconds of execution interval. Only the first function is executed immediately without any interval.	0
condition	Function	A function which returns boolean is used as a condition to exit loop.	null

Example

const mildloop = require("mildloop");

//
// prepare async function & thier param. it's up to you:
//

// params to be passed to each executing functions:
var params = ["a", "b", "c", "d"];

// async function you want to execute repeatedly:
function asyncfn(s, cb) {
  setTimeout(() => {
    if (typeof s == "string")
      return cb && cb(null, s.toUpperCase());
    else
      return cb && cb(Error(s + " must be a string"));
  }, 0);
}


//
// Ok, loop them:
// sets `suspend:true`. It means async loop is suspended if any error occurred.
//

// mildloop options:
var options = {
  suspend: true, // suspend if any error occurred. Defaults to false.
}

// Let's use mildloop!
const instance = mildloop({ params, fn: asyncfn, options }, (errors, results, status) => {
  console.log("status:", status);
  console.log("errors:", errors);
  console.log("results:", results);
});

// If you want to stop the loop, you can stop it by yourself in the middle:
// instance.stop(); // returned `status` on the callback will be set as "terminated"

/*
console log:

status: finished
errors: null
results: [ 'A', 'B', 'C', 'D' ]
*/

mildloop callback function returns (errors, results, status).

• error: Errors (array) of each function. If all function returned no error, errors is null but not array.
• results: Always array object. Each element is a result of each async function.
• status: "finished", "suspended", "terminated", or "condition_matched".
  • If you set option.suspend: true and any error occurred, status is "suspended".
  • If you stop() the loop by yourself, "terminated" is set.
  • If you set condition option and it is matched, the execution loop is suspended and "condition_matched" is set.

If you need more examples, please check example/.