horologe

Install

npm install --save horologe

horologe is now at version 2. There have been changes. Check this documentation to see what is different from version 1.

Usage

var Timer = require('horologe');
var count = 0;
var timer = Timer.create(1000, {sync: true});
timer.on('tick', function(time, passed){
    var d = new Date(time);
    console.log((++count) + ' ' + d.getHours()+':'+d.getMinutes()+':'+d.getSeconds() + ' ' + passed);
});
timer.start(20);

or create, and setup all at once.

var count = 0, timer = Timer.create(1000, {sync: true}).on('tick', onTick).start(5);
 
function onTick(time, passed){
    var d = new Date(time);
    console.log((++count)+d.getHours()+':'+d.getMinutes()+':'+d.getSeconds() + ' ' + passed);
}

Timer creation

new Timer(interval, options)

interval is the time between ticks.

options is an optional object argument.

There are two ways to create a timer.

let timer1 = Timer.create(1000, {});
let timer2 = new Timer(1000, {});

options

options.sync = 1000

What should the timer be synchronized to? Using milliseconds you can adjust the timer synchronization to system time. Using a falsy value will set no synchronization.

options.tick = null

Set a tick function. This is the same as timer.on('tick', ()=>{})

options.highres = false

options.highres is an experimental option. Setting it will make the timer use performance.now() instead of Date.now() for timing.

options.name

Set the name property of the timer.

Properties

timer.interval

The interval set in the constructor.

timer.paused

Is the timer paused?

timer.running

Is the timer running?

timer.count

How many ticks of the timer have been done?

timer.percent

What's the percentage of time complete until the timer is stopped by it's range? If the range is infinite timer.percent returns zero.

timer.name

The name set in the options.

timer.startTime

Get the time that the timer started. timer.startTime returns null if the timer is not running.

Methods

timer.start(wait)

Start the timer at the current time.

The wait parameter is optional. Specify an integer duration for the first tick to wait. If wait isn't set then the most optimal period before the first tick is chosen using rounding to the nearest interval in the past, or future.

If the timer has already started, and hasn't been paused timer.start() does nothing.

timer.range(amount)

timer.range(amount) sets the time range, or when the timer ends. The default is Infinity.

timer.stop()

Stop the timer. timer.stop() resets the timer entirely to a non-running, and non-paused state.

timer.pause(limit)

Pause the timer.

limit has a default of Infinity.

limit controls how long the timer will be paused.

on(name, callback)

Set a listener on an event.

off(name, callback)

Remove a listener.

dispose()

Destroy the timer.

Events

tick

Emitted at every interval of the timer.

The arguments to the listener are time, and passed.

timer.on('tick', function(time, passed){
 
});

time is the current system time.

passed is how much time has passed since the timer was started.

start

Emitted when the timer is started.

startTime is the only argument for the start listener.

timer.on('start', function(startTime){
 
});

stop

Emitted when the timer is stopped. No arguments are passed to the listener.

pause

Emitted when the timer is paused. No arguments are passed to the listener.

complete

Emitted when the timer ends, and only if an amount is passed to the range method.

timer.on('complete', (time, passed)=>{
 
});

About

The horologe timer is very close to the millisecond precision. At worst it will be off by a 100th of a second. In my tests it remained in the 2 millisecond range of precision for most iterations of the interval. horologe doesn't use precision.now so keep that in mind.