/**
 * jQuery Form Input Prompt Plugin 0.5.1
 *
 * Seemingly populate form inputs with text that disappears when the field is focussed.
 * Works by not actually modifying the form field at all, instead an overlay div with
 * the prompt text is added to the DOM. This approach works better than direct
 * form field modification with AJAX-submitted forms and components.
 *
 * This script will become unnecessary once target browsers support HTML 5 and the
 * placeholder attribute for form fields.
 *
 * Usage
 *
 *  $('input#first_name').form_prompt('Don');
 *  $('input#email').form_prompt(function() {
 *    return $(this).attr('alt');
 *  });
 *  $('textarea#description').form_prompt('Type your message here', {
 *    className: 'form-prompt-class'
 *  });
 *
 * Copyright (c) Henry Poydar (henry@poydar.com)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * Contributors: xaviershay, triplef, binary42
 *
**/

(function($) {

    // Setup jQuery object method based on the definition below
    $.fn.form_prompt = form_prompt;

    function form_prompt(text, options) {
    
        var prompt_text = '';
        options = options || {};
    
        // If text is passed as a callback, evaluate it
        if ($.isFunction(text)) {
            prompt_text = text.call(this);
        } else {
            prompt_text = text;
        }

        // Evaluate options
        var className = options.className || 'form-prompt-text';
        var wrapperClassName = options.wrapperClassName || 'form-prompt-wrapper';

        return this.each(function() {
    
            var input = $(this);
            var wrapper = $('<span style="position:relative;overflow:hidden;display:inline-block;" />');
      
            // Use native placeholder attribute in Safari
            if ($.browser.safari) {
              input.attr('placeholder', prompt_text);
              return;
            }

            // This may need adjustment for MSIE ...
            var priorClasses = wrapper.attr('class');
            input.wrap(wrapper.addClass(wrapperClassName));
            wrapper.attr('class', priorClasses);

            if (input.val() == '') {
                input.after("<div class='" + className + "'>" + prompt_text + "</div>");
            } else {
                input.after("<div class='" + className + "'></div>");
            }

            var wrapper = input.parent('.' + wrapperClassName);
            var prompt = wrapper.find('.' + className);

            prompt.css("position", "absolute");
            prompt.css("top", "0");
            prompt.css("left", "0");
            prompt.css("z-index", "1000");
      
            var changeInput = function() {
                prompt.toggle(input.val() == '');
            }
            var selectInput = function() {
                input.focus();
                changeInput();
            //prompt.hide();
            }

            input.click(selectInput);   // Form field is clicked
            input.keyup(selectInput);   // Form field is tabbed into
            prompt.click(selectInput);  // Prompt element is clicked

            input.change(changeInput);
            input.blur(changeInput);
            input.bind('paste', changeInput);

            if (document.readyState == 'complete')
                changeInput();
            else
                $(document).ready(changeInput);
        });
    };

})(jQuery);