[Code] 格式化民國年
這個方法用 proxy 擴充 dayjs，讓 dayjs 支援格式化民國年。
JS 程式碼 // dayx.js
import day from "dayjs";
const prototype = Object.getPrototypeOf(day());
const yyy = (dt) => (dt.getFullYear() - 1911).toString().padStart(3, "0");
const handler = {
get: function (target, prop, receiver) {
// age, dte, tme
if (prop === "age") return day().diff(receiver, "years", false);
if (prop === "dte") return receiver.format("YYYMMDD");
if (prop === "tme") return receiver.format("HHmmss");
// format
if (prop === "format")
return (format) => {
const formattingTokens = /Y{4,}|Y{3}|[^Y{3}]+/g;
const arr = format.match(formattingTokens);
const format2 = arr
.map((x) => (x === "YYY" ? yyy(target.$d) : x))
.join("");
console.log("ktformat", format2);
return new day(target.$d).format(format2);
};
// Return the original property value
if (typeof target[prop] !== "function") return target[prop];
// Wrap the original function with custom behavior
return function (...args) {
const result = target[prop].apply(target, args);
const isReturnDayjs = Object.getPrototypeOf(result) === prototype;
return isReturnDayjs ? p(result, handler) : result;
};
},
set(obj, prop, v, receiver) {
if (prop === "dte") {
v = v.padStart(7, "0");
const yyy = parseInt(v.substring(0, 3)) + 1911;
obj.$d.setFullYear(yyy);
obj.$d.setMonth(parseInt(v.substring(3, 5)) - 1);
obj.$d.setDate(parseInt(v.substring(5, 7)));
return receiver;
}
if (prop === "tme") {
v = v.padEnd(6, "0");
obj.$d.setHours(parseInt(v.substring(0, 2)));
obj.$d.setMinutes(parseInt(v.substring(2, 4)));
obj.$d.setSeconds(parseInt(v.substring(4, 6)));
return receiver;
}
return Reflect.set(...arguments);
},
};
const p = (...args) => new Proxy(day(...args), handler);
export default p;
型別定義 // dayx.d.ts
import dayjs from "dayjs";
declare module "dayjs" {
interface Dayjs {
age: number;
dte: string;
tme: string;
}
}
export = dayjs;
export as namespace dayjs;
使用方式 可直接設定民國年，此外時間的加減乘除都可以參照 dayjs 文件
