// ==UserScript==
// @name Derpibooru Comment Enhancements
// @description Improvements to Derpibooru's comment section
// @version 1.3.12
// @author Marker
// @license MIT
// @namespace https://github.com/marktaiwan/
// @homepageURL https://github.com/marktaiwan/Derpibooru-Link-Preview
// @supportURL https://github.com/marktaiwan/Derpibooru-Link-Preview/issues
// @include https://derpibooru.org/*
// @include https://trixiebooru.org/*
// @include https://www.derpibooru.org/*
// @include https://www.trixiebooru.org/*
// @include /^https?://(www\.)?(derpibooru|trixiebooru)\.org(/.*|)$/
// @grant none
// @noframes
// @require https://openuserjs.org/src/libs/soufianesakhi/node-creation-observer.js
// ==/UserScript==
(function() {
'use strict';
const HOVER_ATTRIBUTE = 'comment-preview-active';
var fetchCache = {};
var backlinksCache = {};
function timeAgo(ele) {
// Firefox 57/Greasemonkey 4 compatibility
var booru = window.booru || window.wrappedJSObject.booru;
booru.timeAgo(ele);
}
function displayHover(comment, sourceLink) {
const PADDING = 5; // in pixels
comment = comment.cloneNode(true);
comment.id = 'hover_preview';
comment.style.position = 'absolute';
comment.style.maxWidth = '980px';
comment.style.minWidth = '490px';
comment.style.boxShadow = '0px 0px 12px 0px rgba(0, 0, 0, 0.4)';
// Make spoiler visible
var i;
var list = comment.querySelectorAll('span.spoiler, span.imgspoiler, span.imgspoiler img');
if (list !== null) {
for (i = 0; i < list.length; i++) {
if (list[i].matches('span')) {
list[i].style.color = '#333';
list[i].style.backgroundColor = (list[i].matches('span.imgspoiler')) ? '' : '#f7d4d4';
} else {
list[i].style.visibility = 'visible';
}
}
}
// highlight reply link
var ele = sourceLink;
while (ele.parentElement !== null && !ele.matches('article')) ele = ele.parentElement;
var sourceCommentID = ele.id.slice(8);
list = comment.querySelectorAll('a[href$="#comment_' + sourceCommentID + '"]');
if (list !== null) {
for (i = 0; i < list.length; i++) list[i].style.textDecoration = 'underline dashed';
}
// relative time
timeAgo(comment.querySelectorAll('time'));
var container = document.getElementById('image_comments') || document.getElementById('content');
if (container) container.appendChild(comment);
// calculate link position
var linkRect = sourceLink.getBoundingClientRect();
var linkTop = linkRect.top + viewportPosition().top;
var linkLeft = linkRect.left + viewportPosition().left;
var commentRect = comment.getBoundingClientRect();
var commentTop;
var commentLeft;
if (sourceLink.parentElement.classList.contains('comment_backlinks')) {
// When there is room, place the preview below the link,
// otherwise place it above the link
if (document.documentElement.clientHeight - linkRect.bottom > commentRect.height + PADDING) {
commentTop = linkTop + linkRect.height + PADDING;
commentLeft = (commentRect.width + linkLeft < document.documentElement.clientWidth) ? (
linkLeft
) : (
document.documentElement.clientWidth - (commentRect.width + PADDING)
);
} else {
commentTop = linkTop - commentRect.height - PADDING;
commentLeft = (commentRect.width + linkLeft < document.documentElement.clientWidth) ? (
linkLeft
) : (
document.documentElement.clientWidth - (commentRect.width + PADDING)
);
}
} else {
// When there is room, place the preview above the link
// otherwise place it to the right and aligns it to the top of viewport
if (linkRect.top > commentRect.height + PADDING) {
commentTop = linkTop - commentRect.height - PADDING;
commentLeft = (commentRect.width + linkLeft < document.documentElement.clientWidth) ? (
linkLeft
) : (
document.documentElement.clientWidth - (commentRect.width + PADDING)
);
} else {
commentTop = viewportPosition().top + PADDING;
commentLeft = linkLeft + linkRect.width + PADDING;
}
}
comment.style.top = commentTop + 'px';
comment.style.left = commentLeft + 'px';
}
function linkEnter(sourceLink, targetCommentID) {
sourceLink.setAttribute(HOVER_ATTRIBUTE, 1);
var targetComment = document.getElementById('comment_' + targetCommentID);
if (targetComment !== null) {
if (!elementInViewport(targetComment)) {
displayHover(targetComment, sourceLink);
}
// Highlight linked post
targetComment.children[0].style.backgroundColor = 'rgba(230,230,30,0.3)';
if (targetComment.querySelector('.comment_backlinks') !== null) targetComment.children[1].style.backgroundColor = 'rgba(230,230,30,0.3)';
} else {
// External post, display from cached response if possible
if (fetchCache[targetCommentID] !== undefined) {
displayHover(fetchCache[targetCommentID], sourceLink);
} else {
fetch(window.location.origin + '/comment/' + targetCommentID + '.html')
.then((response) => response.text())
.then((text) => {
if (fetchCache[targetCommentID] === undefined && sourceLink.getAttribute(HOVER_ATTRIBUTE) !== '0') {
var d = document.createElement('div');
d.innerHTML = text;
fetchCache[targetCommentID] = d.firstChild;
displayHover(d.firstChild, sourceLink);
}
});
}
}
}
function linkLeave(sourceLink, targetCommentID) {
sourceLink.setAttribute(HOVER_ATTRIBUTE, 0);
var targetComment = document.getElementById('comment_' + targetCommentID);
var preview = document.getElementById('hover_preview');
if (targetComment !== null) {
targetComment.children[0].style.backgroundColor = ''; //remove comment highlight
if (targetComment.querySelector('.comment_backlinks') !== null) targetComment.children[1].style.backgroundColor = '';
}
if (preview !== null) preview.parentElement.removeChild(preview);
}
// Chrome/Firefox compatibility hack for getting viewport position
function viewportPosition() {
return {
top: (document.documentElement.scrollTop || document.body.scrollTop),
left: (document.documentElement.scrollLeft || document.body.scrollLeft)
};
}
function elementInViewport(el) {
var rect = el.getBoundingClientRect();
return (
rect.top + (rect.height - 50) >= 0 &&
rect.bottom - (rect.height - 50) <= document.documentElement.clientHeight
);
}
function createBacklinksContainer(commentBody) {
var ele = commentBody.querySelector('div.comment_backlinks');
if (ele === null) {
ele = document.createElement('div');
ele.className = 'block__content comment_backlinks';
ele.style.fontSize = '12px';
// Firefox 57 Workaround: getComputedStyle(commentBody.firstChild)['border-top'] returns an empty string
ele.style.borderTopStyle = window.getComputedStyle(commentBody.firstChild)['border-top-style'];
ele.style.borderTopWidth = window.getComputedStyle(commentBody.firstChild)['border-top-width'];
ele.style.borderTopColor = window.getComputedStyle(commentBody.firstChild)['border-top-color'];
commentBody.insertBefore(ele, commentBody.querySelector('.communication__options'));
}
return ele;
}
function insertBacklink(backlink, commentID) {
// add to cache
if (backlinksCache[commentID] === undefined) backlinksCache[commentID] = [];
if (backlinksCache[commentID].findIndex((ele) => (ele.hash == backlink.hash)) == -1) {
backlinksCache[commentID].push(backlink);
}
var commentBody = document.getElementById('comment_' + commentID);
if (commentBody !== null) {
var linksContainer = createBacklinksContainer(commentBody);
// insertion sort the links so they are ordered by id
if (linksContainer.children.length > 0) {
var iLinkID = parseInt(backlink.hash.slice(9), 10);
var iTempID;
var i;
for (i = 0; i < linksContainer.children.length; i++) {
iTempID = parseInt(linksContainer.children[i].hash.slice(9), 10);
if (iLinkID == iTempID) { // prevent links to the same comment from being added multiple times
return;
}
if (iLinkID < iTempID) {
linksContainer.insertBefore(backlink, linksContainer.children[i]);
return;
}
}
}
linksContainer.appendChild(backlink);
return;
}
}
function getQueryVariable(key, HTMLAnchorElement) {
var i;
var array = HTMLAnchorElement.search.substring(1).split('&');
for (i = 0; i < array.length; i++) {
if (key == array[i].split('=')[0]) {
return array[i].split('=')[1];
}
}
}
function insertButton(displayText) {
var commentsBlock = document.querySelector('.js-editable-comments');
var ele = document.createElement('div');
ele.className = 'block__header';
ele.id = 'comment_loading_button';
ele.style.textAlign = 'center';
ele.appendChild(document.createElement('a'));
ele.firstChild.style.padding = '0px';
ele.firstChild.style.width = '100%';
ele.firstChild.innerText = displayText;
commentsBlock.insertBefore(ele, commentsBlock.lastElementChild);
return ele;
}
function loadComments(e, imageId, nextPage, lastPage) {
e.target.parentElement.remove();
var btn = insertButton('Loading...');
var fetchURL = window.location.origin + '/images/' + imageId + '/comments?id=' + imageId + '&page=' + nextPage;
fetch(fetchURL, {credentials: 'same-origin'}) // cookie needed for correct pagination
.then((response) => response.text())
.then((text) => {
// response text => documentFragment
var ele = document.createElement('div');
var range = document.createRange();
ele.innerHTML = text;
range.selectNodeContents(ele.firstChild);
var fragment = range.extractContents();
var commentsBlock = document.getElementById('image_comments');
// update pagination blocks
commentsBlock.replaceChild(fragment.firstChild, commentsBlock.firstElementChild);
commentsBlock.replaceChild(fragment.lastChild, commentsBlock.lastElementChild);
// page marker
ele.innerHTML = '';
ele.className = 'block block__header';
ele.style.textAlign = 'center';
ele.innerText = 'Page ' + nextPage;
// relative time
timeAgo(fragment.querySelectorAll('time'));
fragment.insertBefore(ele, fragment.firstElementChild);
commentsBlock.insertBefore(fragment, commentsBlock.lastElementChild);
// configure button to load the next batch of comments
btn.remove();
if (nextPage < lastPage) {
btn = insertButton('Load more comments');
btn.addEventListener('click', (e) => {
loadComments(e, imageId, nextPage + 1, lastPage);
});
}
});
}
NodeCreationObserver.onCreation('article[id^="comment_"]', function (sourceCommentBody) {
var links = sourceCommentBody.querySelectorAll('.communication__body__text a[href*="#comment_"]');
var sourceCommentID = sourceCommentBody.id.slice(8);
var ele = sourceCommentBody.querySelector('.communication__body__sender-name');
var sourceAuthor = (ele.firstElementChild !== null && ele.firstElementChild.matches('a')) ? ele.firstElementChild.innerText : ele.innerHTML;
links.forEach((link) => {
var targetCommentID = link.hash.slice(9); // Example: link.hash == "#comment_5430424"
var backlink;
// add backlink if the comment is not part of a quote
// and not fetched
if (!link.matches('blockquote a') && !sourceCommentBody.matches('.fetched-comment')) {
backlink = document.createElement('a');
backlink.style.marginRight = '5px';
backlink.href = '#comment_' + sourceCommentID;
backlink.textContent = '►';
backlink.innerHTML += sourceAuthor;
backlink.addEventListener('mouseenter', () => {
linkEnter(backlink, sourceCommentID);
});
backlink.addEventListener('mouseleave', () => {
linkLeave(backlink, sourceCommentID);
});
backlink.addEventListener('click', () => {
// force pageload instead of trying to navigate to a nonexistent anchor on the current page
if (document.getElementById('comment_' + sourceCommentID) === null) window.location.reload();
});
insertBacklink(backlink, targetCommentID);
}
// ignore quotes
// this is terrible
if (link.nextElementSibling &&
link.nextElementSibling.nextElementSibling &&
link.nextElementSibling.nextElementSibling.matches('blockquote')) return;
link.addEventListener('mouseenter', () => {
linkEnter(link, targetCommentID);
});
link.addEventListener('mouseleave', () => {
linkLeave(link, targetCommentID);
});
});
// If other pages had replied to this comment
if (backlinksCache[sourceCommentID] !== undefined) {
backlinksCache[sourceCommentID].forEach((backlink) => {
insertBacklink(backlink, sourceCommentID);
});
}
});
// Comment loading
NodeCreationObserver.onCreation('#image_comments nav>a.js-next', function (btnNextPage) {
if (document.getElementById('comment_loading_button') !== null) return;
var btnLastPage = btnNextPage.nextElementSibling;
var imageId = getQueryVariable('id', btnNextPage);
var nextPage = parseInt(getQueryVariable('page', btnNextPage), 10);
var lastPage = parseInt(getQueryVariable('page', btnLastPage), 10);
var btn = insertButton('Load more comments');
btn.addEventListener('click', (e) => {
loadComments(e, imageId, nextPage, lastPage);
});
});
})();
