/**
 * 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: 'highlight'
	}, 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.value === $(this).data('label')) {
				this.value = this.defaultValue;
				$(this).removeClass(settings.labelledClass);
			}
		}).blur(function(){
			if (this.value === this.defaultValue) {
				this.value = $(this).data('label');
				$(this).addClass(settings.labelledClass);
			}
		});
		
		var removeValuesOnExit = function() {
			jQuery_labellified_elements.each(function(){
				if (this.value === $(this).data('label')) {
					this.value = this.defaultValue;
					$(this).removeClass(settings.labelledClass);
				}
			})
		};
		
		$(this).parents('form').submit(removeValuesOnExit);
		$(window).unload(removeValuesOnExit);
		
		if (this.value !== this.defaultValue) {
			// user already started typing; don't overwrite their work!
			return;
		}
		// actually set the value
		this.value = $(this).data('label');
		$(this).addClass(settings.labelledClass);

	});
};