/**
 * jQuery.labelify - Display in-textbox hints
 * Stuart Langridge, http://www.kryogenix.org/
 * Released into the public domain
 * Date: 25th June 2008
 * @author Stuart Langridge
 * @version 1.3
 *
 *
 * Basic calling syntax: $("input").labelify();
 * Defaults to taking the in-field label from the field's title attribute
 *
 * You can also pass an options object with the following keys:
 *   text
 *     "title" to get the in-field label from the field's title attribute 
 *      (this is the default)
 *     "label" to get the in-field label from the inner text of the field's label
 *      (note that the label must be attached to the field with for="fieldid")
 *     a function which takes one parameter, the input field, and returns
 *      whatever text it likes
 *
 *   labelledClass
 *     a class that will be applied to the input field when it contains the
 *      label and removed when it contains user input. Defaults to blank.
 *  
 */
jQuery.fn.labelify = function(settings) {
	settings = jQuery.extend( {
		text : "title",
		labelledClass : ""
	}, settings);
	var lookups = {
		title : function(input) {
			return $(input).attr("title");
		},
		label : function(input) {
			return $("label[for=" + input.id + "]").text();
		}
	};
	var lookup;
	var jQuery_labellified_elements = $(this);
	return $(this).each(function() {
		if (typeof settings.text === "string") {
			lookup = lookups[settings.text]; // what if not there?
		} else {
			lookup = settings.text; // what if not a fn?
		}
		;
		// bail if lookup isn't a function or if it returns undefined
		if (typeof lookup !== "function") {
			return;
		}
		var lookupval = lookup(this);
		if (!lookupval) {
			return;
		}

		// need to strip newlines because the browser strips them
		// if you set textbox.value to a string containing them    
		$(this).data("label", lookup(this).replace(/\n/g, '~'));
		$(this).focus(function() {
			if ($(this).val().replace(/\n/g, '~') === $(this).data("label")) {
				$(this).val(this.defaultValue);
				$(this).removeClass(settings.labelledClass).focus();
			}
		}).blur(function() {
			if ($(this).val() === '') {
				$(this).val($(this).data("label").replace(/~/g, "\n"));
				$(this).addClass(settings.labelledClass);
			}
		});

		var removeValuesOnExit = function() {
			jQuery_labellified_elements.each(function() {
				if ($(this).val().replace(/\n/g, '~') === $(this).data("label")) {
					$(this).val('');
					$(this).removeClass(settings.labelledClass);
				}
			})
		};

		$(this).parents("form").submit(removeValuesOnExit);
		$(window).unload(removeValuesOnExit);

		if ($(this).val() !== this.defaultValue) {
			// user already started typing; don't overwrite their work!
			return;
		}
		// actually set the value
		$(this).val($(this).data("label").replace(/~/g, "\n"));
		$(this).addClass(settings.labelledClass);
	});
};