/**
 * 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.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);

  });
};