helper functions
๐ฐ CSS โฉ Layout โฉ System โฉ
// 0.1.7 + arr.last()
// 0.1.8 + toString()
// 0.1.9 + isEqualSets()
// 0.2.0 - toString(): + Map, Set
/* ------- โญ๏ธ debug ------- */
// โญ๏ธ log()
export function log(x){ console.log(x) }
/* ------- โญ๏ธ Object ------- */
// โญ๏ธ toString(obj)
export function toString(obj){
// Set
if (String(obj) === '[object Set]')
return `{${[...obj].map(x=>toString(x)).join(', ')}}`;
// Map
if (String(obj) === '[object Map]')
return `{${[...obj].map(p => `${p[0]}โ${toString(p[1])}`).join(', ')}}`;
// function: return its code
if (typeof obj === 'function') return obj.toString();
// NaN
if (obj !== null && obj !== undefined && obj.toString() === 'NaN') return 'NaN';
// convert to string and check if it's an object
let str = JSON.stringify(obj);
let isObject = (/^\{.*\}$/g).test(str); // { ... }
// not an object, return str anyway
if (!isObject) return str;
// IS an object, try to get its methods as well.
let result = [];
for (let key in obj) {
result.push(`${key}: ${toString(obj[key])}`);
}
return `{${result.join(', ')}}`;
}
// ---------- Set Equality ----------
// isEqualSets(a,b)
export function isEqualSets(a, b){
if (a.size !== b.size) return false;
return Array.from(a).every(elem => b.has(elem));
}
// setA.equal(setB)
// Set.prototype.equal = function(setB){
// return isEqualSets(this, setB);
// }
/* ------- โญ๏ธ Array ------- */
// โญ๏ธ escapeHTML()
export function lastOfArray(arr){
return arr[this.length - 1];
}
// โญ๏ธ arr.last()
// Array.prototype.last = function(){
// return this[this.length - 1];
// }
/* ------- โญ๏ธ String ------- */
// โญ๏ธ escapeHTML()
export function escapeHTML(str){
return new Option(str).innerHTML;
}
// โญ๏ธ mapString(str, mapf)
export function mapString(str, mapf){
return Array.prototype.map.call(str, mapf);
};
// โญ๏ธ StringfromCharCodes(65, 70) -> 'ABCDEF'
export function StringfromCharCodes(from, to) {
let array = [];
for (let i = from; i <= to; i++) array.push(i);
return array.map((code) => String.fromCharCode(code)).join('');
}
/* ------- โญ๏ธ DOM: selectors ------- */
// โญ๏ธ $(): select first
export function $(selector, parent = document){
return parent.querySelector(selector);
}
// โญ๏ธ $(): select all
export function $all(selector, parent = document){
return parent.querySelectorAll(selector);
}
/* ------- โญ๏ธ random ------- */
// โญ๏ธ randomInt(min, max): min ... max (included)
export function randomInt(min, max) {
return Math.floor(Math.random()*(max-min+1)) + min;
}
// โญ๏ธ randomElement(arr)
export function randomElement(arr){
return arr[randomInt(0, arr.length - 1)];
}
// โญ๏ธ randomChar(str)
// โญ๏ธ Note: this may not work well with Unicodeโ๏ธ
export function randomChar(str) {
return str[randomInt(0, str.length - 1)];
}
// โญ๏ธ randomColor()
// randomColor(0.5): random color with alpha = 0.5
export function randomColor(alpha) {
const [r,g,b] = [
randomInt(0,255),
randomInt(0,255),
randomInt(0,255)
];
return `rgb(${r} ${g} ${b}${alpha >=0 ? ` / ${alpha}` : ''})`;
}
/**
* โญ๏ธ shuffle(arr)
* - arr is shuffled in place
* @param arr array to shuffle
*/
export function shuffle(arr) {
var n = arr.length;
for (let i = n - 1; i > 0; i--) {
let j = randomInt(0, i);
[arr[i], arr[j]] = [arr[j], arr[i]];
}
return arr;
}
/**
* โญ๏ธ shuffleString()
* shuffle string
* @param str [string] string to shuffle
*/
export function shuffleString(str){
return shuffle(str.split('')).join('');
}
/* ------- โญ๏ธ Element ------- */
/**
* โญ๏ธ attr(elem, attrName[, value])
* - get: `attr(elem, 'padding')`
* - set: `attr(elem, 'padding', '8px')`
*/
export function attr(elem, attrName, value=undefined){
if (value) { elem.setAttribute(attrName, value) };
return elem.getAttribute(attrName) || undefined;
};
// โญ๏ธ tag(name[, {textContent, attributes}])
// tag('div')
// tag('div', {
// textContent = 'hello',
// attributes = {'--color': 'red'}
// }
export function tag(name, {
textContent,
attributes = {}
}={}){
// create element
let elem = document.createElement(name);
// set text content if necessary
if(textContent) elem.textContent = textContent;
// set attributes
for (const [key, value] of Object.entries(attributes)) {
elem.setAttribute(key, value);
}
// return element
return elem;
}
// โญ๏ธ appendTagTo(node, tag)
export function appendTagTo(node, tagName, {
textContent,
attributes = {}
}={}){
let elem = tag(tagName, {textContent, attributes});
node.appendChild(elem);
return elem;
};
0.1.3 + randomChar(), randomElement()
0.1.4 + mapString(), StringfromCharCodes()
0.1.5 + shuffle(), shuffleString()
0.1.7 + arr.last()
0.1.8 + toString()
0.1.9 + isEqualSets()
0.2.0 - toString(): + Map, Set
Last updated