README.md

martha

🍑 A tiny collection of convenient JavaScript utilities.

Features

• 🔬 Tiny (<1kb gzipped)
• 🚕 Convenient
• 🌲 Tree-shakeable

Installation

npm i martha

Usage

import { qs, on } from 'martha'

let off

function mount() {
  let button = qs('button')

  // add click handler on button
  off = on(button, 'click', () => {
    console.log('click!')
  })
}

function unmount() {
  // remove click handler from button
  off()
}

Functions

off = on(el|els, event, callback)

Add event listener(s) to element or an array of elements. Returns a function to remove the listener(s)

once(el|els, event, callback)

Add event listener(s) to element or array of elements and fire once

add(el|els, cx)

Add provided class(es) to element or array of elements. Multiple classnames should be separated by a space within the string.

remove(el|els, cx)

Remove provided class(es) from element or array of elements. Multiple classnames should be separated by a space within the string.

toggle(el|els, cx)

Toggle provided class from element or array of elements.

has(el|els, cn)

Check if element or array of elements contain the provided classname. Returns a boolean.

attr(el, name[, value])

Get attribute by passing el and attribute name. With a 3rd argument, set and remove attributes (falsy values remove, true boolean sets to empty string). Always returns the attribute value being retrieved, set, or removed.

prop(el, name[, value])

Get custom property value by passing el and property name. With a 3rd argument, you can set properties. Always returns the property value being retrieved or set.

each(array, callback)

Iterate over each item in an array like forEach

{ ww, wh, dpr } = size()

Returns an object containing viewport width (ww) and height (wh) and pixel density (dpr)

index(el)

Returns the index of the provided element amongst it's siblings

rect(el)

Returns the DOMRect of the provided element

qs(selector, [container = document])

Alias for querySelector

qsa(selector, [container = document])

Array-returning alias for querySelectorAll

noop()

Just a noop :-)

clamp(value, min, max)

Clamp a value between two bounds

diagonal(width, height)

Diagonal of a rectangle

distance(x1, y1, x2, y2)

Distance between two points

lerp(currentValue, targetValue, progress)

Linear interpolation

map(value, start1, stop1, start2, stop2)

Maps a value to a new range

norm(value, min, max)

Normalize a value between two bounds

round(value, precision)

Rounds a value to the given precision

wrap(index, length)

Wrap a number around the given length using the modulo operator