README

LoopIterator

Let's you run through an array and go back to the beginning when you run too far. You can also iterate backwards and keep a history.

Installation

npm install loop-iterator --save

Usage

var LoopIterator = require('loop-iterator');

var iterator = new LoopIterator(['Ina', 'Sebastian', 'Henner']);
console.log(iterator.current()); // 'Ina'
console.log(iterator.next()); // 'Sebastian'
console.log(iterator.next()); // 'Henner'
console.log(iterator.next()); // 'Ina'
console.log(iterator.prev()); // 'Henner'

Set the index to whichever value you want and the iterator stays in the allowed range by circulating.

var LoopIterator = require('loop-iterator');

var iterator = new LoopIterator(['Ina', 'Sebastian', 'Henner']);
console.log(iterator.currentIndex()); // 0
console.log(iterator.currentIndex(4)); // 1
console.log(iterator.currentIndex(-1)); // 2
console.log(iterator.currentIndex(3)); // 0

var counter = 0;
setInterval(function(){
    iterator.currentIndex(counter); //0, 1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 2...
    iterator.current(); //'Ina', 'Sebastian', 'Henner', 'Ina', 'Sebastian', 'Henner'...
    counter++;
}, 1000);

If you want to use the history add a second parameter with the number of items you want to record to the constructor.

var LoopIterator = require('loop-iterator');

var iterator = new LoopIterator(['Ina', 'Sebastian', 'Henner'], 2);
console.log(iterator.next()); // 'Sebastian'
console.log(iterator.next()); // 'Henner'
console.log(iterator.next()); // 'Ina'
console.log(iterator.history(1)); // 'Henner', you can also write history() instead
console.log(iterator.history(2)); // 'Sebastian'
console.log(iterator.history(3)); // undefined, history not long enough

Instead of require you can also just use a good old script tag.

<script src="loop-iterator.js"/>

Documentation

Constructor:

LoopIterator(array [, history])

array - The array you want to iterate over.
history - Optional. The number of elements you want to keep in the history.

Methods:

current() : Returns the current element.
next() : Iterates to the next element and returns it.
prev() : Iterates to the previous element and returns it.
currentIndex([index]) : Returns or sets the current index.
nextIndex() : Iterates to the next element and returns the index.
prevIndex() : Iterates to the previous element and returns the index.
history(level) : Returns the n'th element in history. level defaults to 1.
historyIndex(level) : Returns the n'th index in history. level defaults to 1.

Release History

0.3.1 Fixes bug when accessing history before there is any history.
0.3.0 Added circulation functionality when setting the index
0.2.0 Optimizations
0.1.0 Initial release

loop-iterator

Usage no npm install needed!