A jQuery plugin that converts a textarea to a auto-growing textarea

jquery.autogrow.js

/**
 * Autogrow, version 1.0
 * Copyright (c) 2012, marlun78
 * MIT License, https://gist.github.com/marlun78/bd0800cf5e8053ba9f83
 * 
 * A jQuery plugin that converts a textarea to a (Facebook-like) auto-growing textarea. 
 * Built for jQuery 1.5.1
 */
$.fn.autogrow = function () {
    var refresh = function (area, element) {
        var br = '<br/>';
        element.html(area.val().replace(/\n/g, br) + br);
        area.height(element.height());
    };
    this.each(function () {
        var area = $(this), shadow = null;
        area.bind({
            blur: function () {
                shadow.remove();
            },
            focus: function () {
                shadow = $('<div/>').css({
                    'border': area.css('border'),
                    'font-family': area.css('font-family'),
                    'font-size': area.css('font-size'),
                    'font-weight': area.css('font-weight'),
                    'line-height': area.css('line-height'),
                    'margin-top': '-999em',
                    'padding': area.css('padding'),
                    'position': 'absolute',
                    'width': area.width(),
                    'word-wrap': 'break-word'
                }).appendTo($('body'));
                refresh(area, shadow);
            },
            keyup: function () {
                refresh(area, shadow);
            }
        });
        area.css('overflow', 'hidden');
    });
};