jquery.textchange.js

/*!
 * jQuery TextChange Plugin
 * http://www.zurb.com/playground/jquery-text-change-custom-event
 *
 * Copyright 2010, ZURB
 * Released under the MIT License
 */
(function ($) {

	$.fn.textchanged = function() {
		$.event.special.textchange.triggerIfChanged($(this));
	};	

	$.event.special.textchange = {
		
		setup: function (data, namespaces) {
		  $(this).data('lastValue', this.contentEditable === 'true' ? $(this).html() : $(this).val());
			$(this).bind('keyup.textchange', $.event.special.textchange.handler);
			$(this).bind('cut.textchange paste.textchange input.textchange', $.event.special.textchange.delayedHandler);
		},
		
		teardown: function (namespaces) {
			$(this).unbind('.textchange');
		},
		
		handler: function (event) {
			$.event.special.textchange.triggerIfChanged($(this));
		},
		
		delayedHandler: function (event) {
			var element = $(this);
			setTimeout(function () {
				$.event.special.textchange.triggerIfChanged(element);
			}, 25);
		},
		
		triggerIfChanged: function (element) {
		  var current = element[0].contentEditable === 'true' ? element.html() : element.val();
			if (current !== element.data('lastValue')) {
				element.trigger('textchange',  [element.data('lastValue')]);
				element.data('lastValue', current);
			}
		}
	};
	
	$.event.special.hastext = {
		
		setup: function (data, namespaces) {
			$(this).bind('textchange', $.event.special.hastext.handler);
		},
		
		teardown: function (namespaces) {
			$(this).unbind('textchange', $.event.special.hastext.handler);
		},
		
		handler: function (event, lastValue) {
			if ((lastValue === '') && lastValue !== $(this).val()) {
				$(this).trigger('hastext');
			}
		}
	};
	
	$.event.special.notext = {
		
		setup: function (data, namespaces) {
			$(this).bind('textchange', $.event.special.notext.handler);
		},
		
		teardown: function (namespaces) {
			$(this).unbind('textchange', $.event.special.notext.handler);
		},
		
		handler: function (event, lastValue) {
			if ($(this).val() === '' && $(this).val() !== lastValue) {
				$(this).trigger('notext');
			}
		}
	};	

})(jQuery);

Added textchanged method.

Usage: call $(elem).textchanged(); after you manually set the value of an input (using jquery or not), so the textchange,hastext and notext events are fired.

How do you get the textchanged function to work? Setting the event handler for "hastext" works, but calling textchanged does nothing (undefined returned when trying in debugger console).

$("#Task_TitleInput").off("hastext").on("hastext", $.proxy(function ()
            {
                    this.EnableSubmitButton();
            },
            this));

$("#Task_TitleInput").textchanged();

Try to use bind / unbind instead.
on/off require that the event bubbles.
It should be the case though.
try replacing trigger with triggerHandler in the source code.
And please provide a jsfiddle.net sample of the non working code.