/**
* @author: K. Lae Kettavong
*
* @date: 4/22/19
*
* @description: Using node, moment, ES6, and IIFE to demonstrate polymorphism,
* static static funtions and "private" variables
*
*/
const moment = require("moment");
// using IIFE to encapsulate "private" members
const DateFormatter = (() => {
// date formats used in SLO-Service repo
const format = {
SPACE_MMMM_YYYY: "MMMM YYYY", // March 2019
COMMA_MMM_DD_YYYY: "MMM DD, YYYY", // Mar 18, 2019
COMMA_MMMM_DD_YYYY: "MMMM DD, YYYY", // March 18, 2019
COMMA_MMMM_DO_YYYY: "MMMM Do, YYYY", // March 18th, 2019
SLASH_MM_DD_YY: "MM/DD/YY", // 03/18/19
SLASH_MM_YYYY: "MM/YYYY", // 03/2019
SLASH_MM_DD_YYYY: "MM/DD/YYYY", // 03/18/2019
DASH_YYYY_MM: "YYYY-MM", // 2019-03
DASH_YYYY_MM_DD: "YYYY-MM-DD", // 2019-03-18
}
const InvalidDateError = class extends Error {
constructor(msg = "Invalid date") {
super(msg);
}
}
return class {
/**
* Returns date in full month and year format
* @function getFullMonthYear
* @param {string} date - date string to format
* @return date in MMMM YYYY format - e.g. March 2019
*/
static getFullMonthYear(date){
return this.getDate(date, format.SPACE_MMMM_YYYY);
}
/**
* Returns date in numeric month and full year format
* @function getShortMonthSlashFullYear
* @param {string} date - date string to format
* @return date in MM/YYYY format - e.g. 03/2019
*/
static getShortMonthSlashFullYear(date){
return this.getDate(date, format.SLASH_MM_YYYY);
}
// returns "private" constants
static get format(){
return format;
}
/**
* Returns date in the specified format
* @function getDate
* @param {string} date - date string to format
* @param {string} format - date format
* @return date in specified format
*/
static getDate(date, format){
this.validate(date, format);
return moment(date).format(format);
}
/**
* Verifies if date in the specified format is valid
* @function validate
* @param {string} date - date string to format
* @param {string} format - date format
* @throws throws InvalidDateError if date and format don't match up
*/
static validate(date, format) {
if(!moment(date, format, true).isValid()) {
this.throwInvalidDateError();
}
}
/**
* Throws InvalidDateError
* @function throwInvalidDateError
* @throws throws InvalidDateError
*/
static throwInvalidDateError(){
throw new InvalidDateError();
}
}
})();
const date = new Date();
console.log(DateFormatter.getFullMonthYear(date)); // March 2019
console.log(DateFormatter.getShortMonthSlashFullYear(date)); // 03/2019
console.log(DateFormatter.getDate(date, DateFormatter.format.DASH_YYYY_MM_DD)); // 2019-03-18
