bookmarklet.js

(function() {
    var path = "http://www.example.com/",
        containerEl = document.createElement("div"),
        frameEl = document.createElement("iframe"),
        styleEl = document.createElement("link");

    var sanitizePostMessage = function (e) {
        if (e.origin === "http://www.example.com/") {
            return false;
        }

        if (typeof e.data === "string") {
            return e.data;
        }

        return false;
    };

    var generateStyle = function () {
        styleEl.setAttribute("type", "text/css");
        styleEl.setAttribute("rel", "stylesheet");
        styleEl.setAttribute("charset", "UTF-8");
        styleEl.setAttribute("href", path + "bookmarklet.css?r=" + Math.random());
    };

    var setElementClasses = function () {
        containerEl.setAttribute("id","bookmarklet-container");
    };

    var render = function() {
        document.head.appendChild(styleEl);
        document.body.appendChild(containerEl);
        containerEl.appendChild(frameEl);
    };

    var attachEvents = function () {
        window.addEventListener("message", function (event) {
            var message = sanitizePostMessage(event);

            switch (message) {
                case "close":
                    close();
                    break;
            }
        });
    };

    var setFrameOptions = function () {
        frameEl.setAttribute("allowTransparency", true);
        frameEl.setAttribute("src", path + "bookmarklet.html?r=" + Math.random());
    };

    var close = function () {
        document.body.removeChild(containerEl);
    };

    var hasClass = function (el, name) {
        return new RegExp('(\\s|^)' + name + '(\\s|$)').test(el.className);
    };

    var addClass = function (el, name) {
        if (!hasClass(el, name)) {
            el.className += (el.className ? ' ' : '') + name;
        }
    };

    var removeClass = function (el, name) {
        if (hasClass(el, name)) {
          el.className=el.className.replace(new RegExp('(\\s|^)' + name + '(\\s|$)'),' ').replace(/^\s+|\s+$/g, '');
       }
    };

    if (document.getElementById("bookmarklet-container") === null) {
        generateStyle();
        setElementClasses();
        setFrameOptions();
        render();
        attachEvents();
    }
}());

gistfile1.txt

This is just some text as a test