Clock Functions

A JavaScript/TypeScript library containing stopwatch and timer classes.

Highlights

• Supports TypeScript!
• Supports Node and browser
• Includes full JSX documentation
• Lightweight code (14kb!)

Installation

npm install clock-functions --save

Usage

const clockFn = require('clock-functions');
// or
import clockFn from 'clock-functions';

Stopwatch

Stopwatch is a class used to measure time in milliseconds.

Constructor

Stopwatch constructor only has one optional parameter:

• autoStart: boolean - if the stopwatch should start automatically. Defaults to false.

const stopwatch = new Stopwatch();
// or
const stopwatch = new Stopwatch(true); //automatically starts!

Methods

Stopwatch has the following methods:

start()

This method starts the stopwatch, if it is not already started.

If the stopwatch is already started, it does nothing.

start(emit: boolean): boolean

Returns false if the stopwatch was already started, otherwise true.

If emit parameter is set to true (default), the onstart event will be emitted.

Example:

let stopwatch = new Stopwatch();
stopwatch.start(); // -> true - the stopwatch has started
stopwatch.start(); // -> false - the stopwatch was already started

stop()

This method stops the stopwatch, if it is not already stopped.

If the stopwatch is already stopped, it does nothing.

stop(emit: boolean): boolean

Returns false if the stopwatch was already stopped, otherwise true.

If emit parameter is set to true (default), the onstop event will be emitted.

Example:

let stopwatch = new Stopwatch();
stopwatch.stop(); // -> false - the stopwatch was already stopped
stopwatch.start();
stopwatch.stop(); // -> true - the stopwatch has stopped

toggle()

This method toggles the stopwatch, depending on its current state.

toggle(emit: boolean): boolean

Returns true if the stopwatch has been started, and false if it has been stopped.

If emit parameter is set to true (default), the onstart or onstop event will be emitted, depending on the action taken.

Example:

let stopwatch = new Stopwatch();
stopwatch.toggle(); // -> true
stopwatch.toggle(); // -> false
stopwatch.toggle(); // -> true
stopwatch.stop();
stopwatch.toggle(); // -> true

isActive()

This method checks if the stopwatch is currently active, i.e. if it was started but wasn't recently stopped.

isActive(): boolean

Example:

let stopwatch = new Stopwatch();
stopwatch.isActive(); // -> false - the stopwatch was never started
stopwatch.start();
stopwatch.isActive(); // -> true - the stopwatch is active

time() and valueOf()

Those methods return the total time the stopwatch has been active for. They can be used interchangably.

time(emit: boolean): number
// or
valueOf(emit: boolean): number

If emit parameter is set to true (default), the ontime event will be emitted.

Example:

stopwatch = new Stopwatch();
stopwatch.start();
// and almost 4 seconds later...
stopwatch.time(); // -> 3914

stopwatch.stop();
// and after some more time...
stopwatch.time(); // -> 3914 - the value hasn't changed

sinceStart()

This method returns the time since the last time the stopwatch has been started.

If the stopwatch was never started, it returns null.

sinceStart(): number | null

Example:

let stopwatch = new Stopwatch();
stopwatch.start();
// and almost 4 seconds later...
stopwatch.stop();
stopwatch.time(); // -> 3914
stopwatch.start();
// some more time later...
stopwatch.time(); // -> 6102
stopwatch.sinceStart(); // -> 2188

reset()

This method resets the stopwatch to 0ms, and keeps its current state.

If the stopwatch was never started, it does nothing.

reset(emit: boolean): boolean

Returns false if the stopwatch was never started, otherwise true.

If emit parameter is set to true (default), the onreset event will be emitted.

Example:

let stopwatch = new Stopwatch();
stopwatch.start();
// and almost 4 seconds later...
stopwatch.time(); // -> 3914
stopwatch.reset();
stopwatch.time(); // -> 0
stopwatch.isActive(); // -> true

cancelStart()

This method cancels the last start. The stopwatch stops, and the time remains as it was on the last stop.

If the stopwatch is stopped, it does nothing.

cancelStart(): boolean

Returns false if the stopwatch was stopped, otherwise true.

Example:

let stopwatch = new Stopwatch();
stopwatch.start();
stopwatch.stop();
stopwatch.start();
stopwatch.cancelStart(); // -> true - the last start was cancelled, and the stopwatch is now inactive
stopwatch.cancelStart(); // -> false - the stopwatch was already stopped

cancelStop()

This method cancels the last stop. The stopwatch starts, and the duration between the last stop and current time gets added to the total.

If the stopwatch is started, it does nothing.

cancelStop(): boolean

Returns false if the stopwatch was started, otherwise true.

Example:

let stopwatch = new Stopwatch();
stopwatch.start();
stopwatch.stop();
stopwatch.cancelStop(); // -> true - the last stop was cancelled, and the stopwatch is now active
stopwatch.cancelStop(); // -> false - the stopwatch was already active

toString()

This method returns the same value as the time() method, but with ms string added at the end.

toString(): string

Example:

let stopwatch = new Stopwatch();
stopwatch.start();
// and almost 4 seconds later...
stopwatch.toString(); // -> "3914ms"

Properties

Stopwatch has the following public properties:

onstart

This property should be a function, and can be freely changed.

It gets called if the onstart event is emitted.

onstop

This property should be a function, and can be freely changed.

It gets called if the onstop event is emitted.

onreset

This property should be a function, and can be freely changed.

It gets called if the onreset event is emitted.

ontime

This property should be a function, and can be freely changed.

It gets called if the ontime event is emitted.

Timer

Timer is a class used to delay the execution of a function.

Constructor

Timer constructor has three parameters:

• delay: number - the amount of time in ms until the function should be called.
• autoStart: boolean - if the timer should start automatically. Optional, defaults to true.
• callback: Function - the function to be called. It can also be specified by setting the object's property onfinish.

const timer = new Timer(10000);
// or
const timer = new Timer(10000, false, () => console.log('Hello world!'));
// or
const timer = new Timer(10000, false);
timer.onfinish = () => console.log('Hello world!');

Methods

Timer methods are extremely similar to Stopwatch methods, but there are no events emitted in any of the functions.

start()

This method starts the timer, if it is not already started.

If the timer is already started, it does nothing.

start(): boolean

Returns false if the timer was already started, otherwise true.

Example:

let timer = new Timer(10000);
timer.start(); // -> true - the timer has started
timer.start(); // -> false - the timer was already started

stop()

This method stops the timer, if it is not already stopped.

If the timer is already stopped, it does nothing.

stop(): boolean

Returns false if the timer was already stopped, otherwise true.

Example:

let timer = new Timer(10000);
timer.stop(); // -> false - the timer was already stopped
timer.start();
timer.stop(); // -> true - the timer has stopped

toggle()

This method toggles the timer, depending on its current state.

toggle(): boolean

Returns true if the timer has been started, and false if it has been stopped.

Example:

let timer = new Timer(10000);
timer.toggle(); // -> true
timer.toggle(); // -> false
timer.toggle(); // -> true
timer.stop();
timer.toggle(); // -> true

isActive()

This method checks if the timer is currently active, i.e. if it was started but wasn't recently stopped.

isActive(): boolean

Example:

let timer = new Timer(10000);
timer.isActive(); // -> false - the timer was never started
timer.start();
timer.isActive(); // -> true - the timer is active

timeRemaining() and valueOf()

Those methods return the time left until the function is called. They can be used interchangably.

time(): number
// or
valueOf(): number

Example:

let timer = new Timer(10000);
// and almost 4 seconds later...
timer.timeRemaining(); // -> 6086

sinceStart()

This method returns the time since the last time the timer has been started.

If the stopwatch was never started, it returns null.

sinceStart(): number | null

Example:

let timer = new Timer(10000);
timer.start();
// and almost 4 seconds later...
timer.stop();
timer.timeRemaining(); // -> 6086
timer.start();
// some more time later...
timer.timeRemaining(); // -> 3898
timer.sinceStart(); // -> 2188

reset()

This method resets the timer back to full delay, and keeps its current state.

If the stopwatch was never started, it does nothing.

reset(): boolean

Returns false if the stopwatch was never started, otherwise true.

Example:

let timer = new Timer(10000);
timer.start();
// and almost 4 seconds later...
timer.timeRemaining(); // -> 6086
timer.reset();
timer.timeRemaining(); // -> 10000
timer.isActive(); // -> true

toString()

This method returns the time remaining out of the full delay, with ms string added at the end.

toString(): string

Example:

let timer = new Timer(10000);
timer.start();
// and almost 4 seconds later...
timer.toString(); // -> "6086/10000ms"

Properties

Timer, unline Stopwatch, only has two properties:

onfinish

This property should be a function, and can be freely changed.

It gets called if the timer onstart reaches 0 milliseconds.

delay

This property is read-only.

It stores the maximum delay in ms after which the callback function should be called.

Constants

Clock Functions library also provides a few useful time-related constants:

• SECOND - equal to 1,000 milliseconds, or 1 second.
• MINUTE - equal to 60,000 milliseconds, or 1 minute.
• HOUR - equal to 3,600,1000 milliseconds, or 1 hour.
• DAY - equal to 86,400,000 milliseconds, or 24 hours.
• MONTH - equal to 2,592,000,000 milliseconds, or 30 days.
• YEAR - equal to 31,536,000,000 milliseconds, or 365 days.