Auto Tab Form fields with maxlength set

autoTab.js

(function(){
  var autoTab = {
		keysPressed : 0,
		init : function () {
			this.keyEvents();
		},
		keyEvents : function () {
			var self = this; self.keyEvents.validKey = false;
			$('input[maxlength]').on('keypress', function(e){
				self.keyEvents.validKey = true;
				if ($(this).attr('type') == 'number' && String.fromCharCode(e.which).match(/^\d+$/) == null) {
					return false;
				}
			});
			$('input[maxlength]').on('keyup', function (e) {
				var nextIndex = $('input,select,button').index($(this)) + 1;
				self.form = $(this).parents('form'), self.keysPressed--;
				/* Get right charcode if numberpad is used */
				if (self.keyEvents.validKey && (e.which >= 96 && e.which <= 105)) {
					var newKey = String.fromCharCode(e.which - 48);
				} else {
					var newKey = String.fromCharCode(e.which);
				}
				
				/* Check if character max is hit */
				if (self.keyEvents.validKey && $(this).val().length < $(this).attr('maxlength')) {
					self.keyEvents.tab = false;
				} else if (self.keyEvents.validKey && ($(this).val().length > $(this).attr('maxlength'))) {
					$(this).val($(this).val().replace(newKey,''));
					if(!self.keysPressed) {
						self.tab(nextIndex);
					}
				} else if (self.keyEvents.validKey) {
					self.tab(nextIndex);
				}
				
				
			});
			$('input[maxlength]').on('keydown', function (e) {
				self.keyEvents.validKey = false;
				self.keysPressed++;
			});
		},
		tab : function (nextIndex) {
			var self = this;
			if (typeof $('input,select,button')[nextIndex] !== "undefined") {
				$('input,select,button')[nextIndex].focus();
			} else {
				self.form.find('button[type=submit], input[type=submit]').focus();
			}
			self.keyEvents.validKey = false;
		}
	}
	autoTab.init();
})($);