mm

Author: RobinHerbots

micromasks/mm.js

@@ -0,0 +1,30 @@
+(() => {
+	window.mm = (i, mask) => {
+		const d = {9: "[0-9]", a: "[a-z]"}, msk = mask.split("");
+		i.addEventListener("input", handler);
+		i.addEventListener("focus", handler);
+
+		function handler(e) {
+			if (e.type === "focus" && i.value !== "") return;
+			let mskd = [],
+				s = i.selectionStart - 1;
+			msk.forEach((el, n) => {
+				if (d[el]) {
+					let t = new RegExp(d[el], "i").test(i.value.charAt(n));
+					mskd.push(t ? i.value.charAt(n) : "_");
+					if (t && s === n && i.value.charAt(n) !== "_") {
+						s++;
+					}
+				} else {
+					mskd.push(el);
+					if (s === n) s++;
+				}
+			});
+			i.value = mskd.join("");
+			i.selectionStart = i.selectionEnd = s < 0 ? 0 : s;
+			setTimeout(function () {
+				i.selectionStart = i.selectionEnd = s < 0 ? 0 : s;
+			}, 0);
+		}
+	};
+})();