Old Reddit Comment Expando

Adds an expando button to show the first few comments under posts on old.reddit.com, with a next button, and RES dark mode support.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Old Reddit Comment Expando
// @namespace    http://tampermonkey.net/
// @version      1.6
// @description  Adds an expando button to show the first few comments under posts on old.reddit.com, with a next button, and RES dark mode support.
// @author       greenwithenvy
// @include     *.reddit.com/*
// @include     *./reddit.com/user/*/submitted
// @license WTFPL
// @grant        GM_xmlhttpRequest
// @grant        GM_addStyle
// ==/UserScript==

(function() {
    'use strict';

    GM_addStyle(`
        .comment-expando {
            cursor: pointer;
            color: #888;
            margin-right: 4px;
            font-size: 10px;
            font-weight: bold;
        }
        .comment-preview {
            margin-top: 5px;
            padding: 5px;
            border-left: 2px solid #0079d3;
            background: #f6f7f8;
            font-size: 12px;
            color: #1a1a1b;
        }
        .comment-next {
            display: block;
            margin-top: 5px;
            cursor: pointer;
            color: #ff4500;
            font-size: 12px;
        }
        .comment-loading {
            color: #ff4500;
            font-size: 14px;
            text-align: center;
        }
        body.res-nightmode .comment-preview {
            background: #1a1a1b;
            color: #d7dadc;
            border-left: 2px solid #ff4500;
        }
        .comment-author {
            font-weight: bold;
            color: #0079d3;
            cursor: pointer;
        }
        body.res-nightmode .comment-author {
            color: #ffb000;
        }
    `);

    document.querySelectorAll('.thing.link').forEach(post => {
        let postUrl = post.querySelector('a.comments')?.href;
        if (!postUrl) return;

        let expandoBtn = document.createElement('span');
        expandoBtn.textContent = '[+ preview comments]';
        expandoBtn.className = 'comment-expando';
        expandoBtn.addEventListener('click', function() {
            if (expandoBtn.nextSibling && expandoBtn.nextSibling.classList.contains('comment-preview')) {
                expandoBtn.nextSibling.remove();
                expandoBtn.textContent = '[+ preview comments]';
                return;
            }
            loadComments(expandoBtn, postUrl);
        });
        post.querySelector('.flat-list.buttons')?.prepend(expandoBtn);
    });

    function loadComments(expandoBtn, postUrl) {
        let loadingText = document.createElement('div');
        loadingText.className = 'comment-loading';
        loadingText.textContent = 'Loading comments...';
        expandoBtn.after(loadingText);

        GM_xmlhttpRequest({
            method: 'GET',
            url: postUrl + '.json',
            onload: function(response) {
                loadingText.remove();
                let data = JSON.parse(response.responseText);
                let comments = data[1].data.children.filter(c => c.kind === "t1").map(c => c.data);

                let previewDiv = document.createElement('div');
                previewDiv.className = 'comment-preview';

                if (comments.length) {
                    let currentCommentIndex = 0;
                    previewDiv.innerHTML = formatComment(comments[currentCommentIndex], postUrl);

                    let nextBtn = document.createElement('span');
                    nextBtn.textContent = '[next]';
                    nextBtn.className = 'comment-next';
                    nextBtn.addEventListener('click', function() {
                        currentCommentIndex = (currentCommentIndex + 1) % comments.length;
                        previewDiv.innerHTML = formatComment(comments[currentCommentIndex], postUrl);
                        previewDiv.appendChild(nextBtn);
                    });

                    previewDiv.appendChild(nextBtn);
                } else {
                    previewDiv.innerHTML = '<p>No comments yet.</p>';
                }

                expandoBtn.textContent = '[- hide comments]';
                expandoBtn.after(previewDiv);
            }
        });
    }

    function formatComment(comment, postUrl) {
        let commentLink = `${postUrl}${comment.id}`;
        let commentBody = comment.body.length > 500 ? comment.body.substring(0, 500) + '...' : comment.body;
        let commentHtml = `<p><a href="${commentLink}" target="_blank" class="comment-author">${comment.author}</a>: ${commentBody}</p>`;
        return commentHtml;
    }
})();