Reddit - Top Comments Preview

// ==UserScript==
// @name           Reddit - Top Comments Preview
// @namespace      http://userscripts.org/scripts/show/126494
// @author         Erik Wannebo (rewritten by gavin19)
// @description    Preview to the top comments on Reddit
// @include        http://www.reddit.com/*
// @exclude        http://www.reddit.com/*/comments/*
// @version        1.02
// ==/UserScript==
(function (nbrComments, comments, commentLinks) {
    var initTCP = {
        init: function () {
            var c;
            document.body.addEventListener('DOMNodeInserted', function (event) {
                if ((event.target.tagName === 'DIV') && (event.target.getAttribute('id') && event.target.getAttribute('id').indexOf('siteTable') !== -1)) {
                        initTCP.addTopLinks();
                }
            }, true);
            initTCP.addTopLinks();
        },
        addTopLinks: function () {
            var i, len, link, articleID, obj = this,
            a = document.querySelectorAll('a.comments');
            if (a.length > commentLinks) {
                for (i = 0, len = a.length; i < len; i += 1) {
                    if (!a[i].parentNode.querySelector('.toplink') && a[i].textContent.match(/[0-9]/)) {
                        articleID = a[i].getAttribute('href');
                        articleID = articleID.substring(articleID.indexOf("/comments/") + 10, articleID.indexOf("/comments/") + 15);
                        link = document.createElement('a');
                        link.className = 'toplink';
                        link.href = 'javascript:void(0);';
                        link.setAttribute('id', 'toplink' + articleID);
                        link.setAttribute('style', 'color:red;text-decoration:none;');
                        link.textContent = '  top';
                        a[i].parentNode.parentNode.querySelector('.first').insertBefore(link, null);
                        (function (link, articleID) {
                            link.addEventListener('click', function () {
                                obj.retrieveTopComments(this, articleID);
                            });
                        })(link, articleID);
                    }
                }
                commentLinks = a.length;
            }
        },
        retrieveTopComments: function (ele, articleID) {
            var pre, thisPre;
            ele = ele.parentNode.parentNode;
            if (!document.querySelector('#' + articleID + 'preview')) {
                pre = document.createElement('div');
                pre.setAttribute('id', articleID + 'preview');
                pre.setAttribute('style', 'font-size:11px;width:100%;max-width:100%;background-color:#f8f899;border-radius:5px;border:solid black 1px;white-space:pre-line;padding:5px;');
                pre.textContent = 'loading...';
                ele.querySelector('.first').insertBefore(pre, null);
                ele.style.display = 'inline-block';
                GM_xmlhttpRequest({
                    method: "GET",
                    url: "http://www.reddit.com/comments/" + articleID + "/.json?limit=" + nbrComments,
                    headers: {
                        "Content-Type": "application/x-www-form-urlencoded"
                    },
                    onload: this.onloadJSON
                });
            } else {
                thisPre = document.querySelector("#" + articleID + "preview");
                thisPre.parentNode.removeChild(thisPre);
                ele.style.display = 'inline';
            }
        },
        onloadJSON: function onloadJSON(response) {
            var i, content, ups, downs, author, contentDiv, pct = 100,
                newHtml = '',
                comments = JSON.parse(response.responseText),
                articleID = comments[0].data.children[0].data.id;
            for (i = 0; i < nbrComments; i += 1) {
                if (comments[1].data.children.length >= (i + 1)) {
                    content = comments[1].data.children[i].data.body_html;
                    if (content !== undefined) {
                        contentDiv = document.createElement('div');
                        contentDiv.innerHTML = content;
                        content = contentDiv.firstChild.textContent;
                        author = comments[1].data.children[i].data.author;
                        ups = comments[1].data.children[i].data.ups;
                        downs = comments[1].data.children[i].data.downs;
                        if (downs > 0) {
                            pct = Math.floor((ups / (ups + downs)) * 100 + 0.5)
                        };
                        newHtml += (i > 0 ? "<hr>" : "") + "<b>" + author + "</b> " + pct + "% +" + ups + " -" + downs + "<br>" + content;
                    }
                }
            }
            document.querySelector('#' + articleID + 'preview').innerHTML = newHtml;
        }
    };
    if (document.body) {
        setTimeout(function () {
            initTCP.init();
        }, 1000);
    } else {
        window.addEventListener("load", function () {
            initTCP.init();
        }, false);
    };
})(nbrComments = 2, comments = "", commentLinks = 0);