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/.