Methodules

Relevant/useful reusable methods for JavaScript. Documents of methods are listed and linked below:

Methods

useUnion - This function will enforce the same type or object given for the new value.

useStrictUnion) - This function will enforce an initialized variable to use the given types everytime a, initialized variable is set to a new value. (Note: limit is default to Infinity).

keySearch - This function will search and return the first matching value.

keySearchAll - This function will search all and return all matching values.

requestData - This function will make any request from a desired API server.

keyValueSwitch - This function will switch all keys and values.

arrayShuffle - This function will shuffle an array.

useUnion(value: any, types: any[])

First argument is the initial/new value of any type. However, the value cannot be a function, because there are no use-cases or no reasonable use-case to enforce the value. It is best to use an arrow function instead useUnion method if the value is intended to be a function.

Second argument is the array of primitive types (String, Number, BigInt, null, etc.) and/or built-in objects (Date, Math, Map, etc.) and/or custom constructor functions.

const a = useUnion('hello world', [String]); // returns: 'hello world'
const b = useUnion(2, [String, Number]); // returns: 2
const c = useUnion([1,2,3], [BigInt]); // returns: Undefined

Objects

const myDate = useUnion(new Date(), [Date]);
const myMap = useUnion(new Map(), [Map]);

console.log(myDate.getFullYear()); // returns current year
console.log(myMap.size); //  returns 0

Constructor function

function Person (name, age) {
  this.name = name;
  this.age = age;
}

const P1 = useUnion(new Person('Alice', 99), [Person]);
const P2 = useUnion(new Person('John', 34), [Object]); // Will return as undefined

console.log(P1.name); //  Alice
console.log(P2.name); //  TypeError: Cannot read properties of undefined (reading 'name')

Use case example:

//  index.js

import { fun } from "../fun.js";

fun.createFun(document.getElementByClassName('fun'));


// fun.js

import { useUnion } from "../methodules.js";

function _createFun(htmlcollection)) {

  if (useUnion(htmlcollection, [HTMLCollection]) {
    htmlcollection.forEach(element => {

      const dataColor = useUnion(element.getAttribute('data-color'), [String]));
      const dataHighLight = useUnion(element.getAttribute('data-highlight'), [Boolean]));

      ...
    });
  }
}
const fun = () => {
  return {
    createFun: _createFun(htmlcollection)
  }
}

export default fun;

useStrictUnion(value: any, types: any[], limit: Number)

Similar to useUnion (and also similar to React's hook useState), this will be an array deconstructing assignment. Call the first argument to get the current value. Call the second argument to set a value.

//  String only
const [value, setValue] = useStrictUnion('hello world', [String]);

console.log(value()); //  'hello world'

setValue(7); // this will error

//  String and Number with a limit of 3 sets
const [alphaNum, setAlphaNum] = useStrictUnion('methodule', [String, Number], 2);

console.log(alphaNum()); //  'methodule'

setAlphaNum(7);

console.log(alphaNum()); //  7

setAlphaNum({name: 'javascript'}); //  this will error
setAlphaNum(8);
setAlphaNum('Error'); // this will error due to number of sets has been exceeded

console.log(alphaNum()); //  alphaNum() should still be Number 8

keySearch(object: any{}, key: String)

First argument MUST be an object, and the second will be the search key string.

function Person(name, age) {
  this.name = name;
  this.age = age;
}

const p1 = new Person('Alice', 45);

console.log(keySearch(p1, name); //  'Alice'

keySearchAll(object: any[] | any{}, key: String)

Like keySearch(), this function accepts an array of objects or a complex object, and returns all values of the same key.

function Person(name, age) {
  this.name = name;
  this.age = age;
}

const people = [new Person('John', 35), new Person('Jane', 35)];

console.log(keySearchAll(people, name)); //  ['John', 'Jane']

requestData(url: String, option: Object)

First argument MUST be a URL string STARTING with 'http://' or 'https://'. Second argument is an object of options to add headers, method, body, etc.

It is highly recommend to use async and await keywords for this function due to fetch() method is promise-based. Using these keywords for readability and error handling.

import { requestData } from "../methodules.js"

const data = async () => {
  return await fetchData("https://jsonplaceholder.typicode.com/posts/1", {method: 'GET'});
};

//  Another way
async function getData(url, option) {
  return await fetchData(url, option);
}

keyValueSwitch(object: any{})

Self-explanatory. Pass in an object to switch the keys and values. (This will copy the referrenced object).

const a = { a: 1, b: 2 };
const b = keyValueSwitch(a);

console.log(a);  //  { a: 1, b: 2 }
console.log(b);  //  { 1: a, 2: b }

arrayShuffle(array: any[])

Self-explanatory. Pass in an array to be shuffled. (This will copy the referrenced array).

const arr = [1,2,3,4,5];

console.log(arrayShuffle(arr));  //  possibilities: [2,4,3,5,1], [1,3,4,2,5], ...