node-callback-queue

Callback queue

Usage

``
const queue = require('node-callback-queue');

function onComplete(err, result){
if(err) {
return console.log('Error: %s', err);
}
console.log('Result %s', result);
}

queue
(
// complete callback
onComplete,

// initial callback
function(next) {
next(null, 'param 1', 'param 2');
},

// queued callback
function(arg1, arg2, next){
console.log("args %s, %s", arg1, arg2);
// output:
// args param 1, param 2
next(null, arg1, arg2, true, 123);
},

// queued callback
function(arg1, arg2, arg3, arg4, next) {
console.log("args %s, %s, %s, %s", arg1, arg2, arg3, arg4);
// output:
// args param 1, param 2, true, 123
next(null, "another arg");
},

// queued callback
function(arg1, next){
console.log("args %s", arg1);
// output:
// args another arg

if(arg1 === "another arg") {
// lets stop execution
return next(new Error("Failed"));
}

// put args as many as next callback requires
next(null, 1, 2, 3, 4, 5);
},

// this callback and next callbacks will be ignored
// because previous callback send an error as first parameter
// to "next"
function(arg1, arg2, arg3, arg4, arg5, next){
// if this method was executed
// this would be final call of current queue with the result
var result = "result";
next(null, result);
}
);
``