feat: ability to go through your posts in a topic

because I am 👴 useful for large topics

install/package.json

@@ -95,7 +95,7 @@
         "nodebb-plugin-spam-be-gone": "0.7.13",
         "nodebb-rewards-essentials": "0.2.1",
         "nodebb-theme-lavender": "5.3.2",
-        "nodebb-theme-persona": "11.3.38",
+        "nodebb-theme-persona": "11.3.39",
         "nodebb-theme-slick": "1.4.23",
         "nodebb-theme-vanilla": "12.1.17",
         "nodebb-widget-essentials": "5.0.9",

public/language/en-GB/global.json

@@ -28,7 +28,7 @@
 
 	"pagination": "Pagination",
 	"pagination.out_of": "%1 out of %2",
-	"pagination.enter_index": "Enter index",
+	"pagination.enter_index": "Go to post index",
 
 	"header.admin": "Admin",
 	"header.categories": "Categories",

public/language/en-GB/topic.json

@@ -207,5 +207,7 @@
 	"timeago_earlier": "%1 earlier",
 	"first-post": "First post",
 	"last-post": "Last post",
+	"go-to-my-next-post": "Go to my next post",
+	"no-more-next-post": "You don't have any other posts in this topic",
 	"post-quick-reply": "Post quick reply"
 }

public/src/modules/navigator.js

@@ -54,15 +54,20 @@ define('navigator', ['forum/pagination', 'components', 'hooks', 'alerts'], funct
 			e.stopPropagation();
 		});
 
-		paginationBlockEl.off('shown.bs.dropdown', '.dropdown').on('shown.bs.dropdown', '.dropdown', function () {
-			setTimeout(function () {
+		paginationBlockEl.off('shown.bs.dropdown', '.wrapper').on('shown.bs.dropdown', '.wrapper', function () {
+			setTimeout(async function () {
 				$('.pagination-block input').focus();
+				const postCountInTopic = await socket.emit('topics.getPostCountInTopic', ajaxify.data.tid);
+				if (postCountInTopic > 0) {
+					paginationBlockEl.find('#myNextPostBtn').removeAttr('disabled');
+				}
 			}, 100);
 		});
 		paginationBlockEl.find('.pageup').off('click').on('click', navigator.scrollUp);
 		paginationBlockEl.find('.pagedown').off('click').on('click', navigator.scrollDown);
 		paginationBlockEl.find('.pagetop').off('click').on('click', navigator.toTop);
 		paginationBlockEl.find('.pagebottom').off('click').on('click', navigator.toBottom);
+		paginationBlockEl.find('#myNextPostBtn').off('click').on('click', gotoMyNextPost);
 
 		paginationBlockEl.find('input').on('keydown', function (e) {
 			if (e.which === 13) {
@@ -90,6 +95,40 @@ define('navigator', ['forum/pagination', 'components', 'hooks', 'alerts'], funct
 		navigator.update(0);
 	};
 
+	let lastNextIndex = 0;
+	async function gotoMyNextPost() {
+		async function getNext(startIndex) {
+			return await socket.emit('topics.getMyNextPostIndex', {
+				tid: ajaxify.data.tid,
+				index: Math.max(1, startIndex),
+				sort: config.topicPostSort,
+			});
+		}
+		if (ajaxify.data.template.topic) {
+			let nextIndex = await getNext(index);
+			if (lastNextIndex === nextIndex) { // handles last post in pagination
+				console.log('fail', nextIndex, lastNextIndex);
+				nextIndex = await getNext(nextIndex);
+			}
+			if (nextIndex) {
+				lastNextIndex = nextIndex;
+				$(window).one('action:ajaxify.end', function () {
+					if (paginationBlockEl.find('.dropdown-menu').is(':hidden')) {
+						paginationBlockEl.find('.dropdown-toggle').dropdown('toggle');
+					}
+				});
+				navigator.scrollToIndex(nextIndex, true, 0);
+			} else {
+				alerts.alert({
+					message: '[[topic:no-more-next-post]]',
+					type: 'info',
+				});
+
+				lastNextIndex = 1;
+			}
+		}
+	}
+
 	function clampTop(newTop) {
 		const parent = thumb.parent();
 		const parentOffset = parent.offset();

src/socket.io/topics.js

@@ -1,9 +1,14 @@
 'use strict';
 
+const _ = require('lodash');
+
+const db = require('../database');
+const posts = require('../posts');
 const topics = require('../topics');
 const user = require('../user');
 const meta = require('../meta');
 const privileges = require('../privileges');
+const cache = require('../cache');
 
 const SocketTopics = module.exports;
 
@@ -54,4 +59,52 @@ SocketTopics.isModerator = async function (socket, tid) {
 	return await user.isModerator(socket.uid, cid);
 };
 
+SocketTopics.getMyNextPostIndex = async function (socket, data) {
+	if (!data || !data.tid || !data.index || !data.sort) {
+		throw new Error('[[error:invalid-data]]');
+	}
+
+	async function getTopicPids(index) {
+		const topicSet = data.sort === 'most_votes' ? `tid:${data.tid}:posts:votes` : `tid:${data.tid}:posts`;
+		const reverse = data.sort === 'newest_to_oldest' || data.sort === 'most_votes';
+		const cacheKey = `np:s:${topicSet}:r:${String(reverse)}:tid:${data.tid}:pids`;
+		const topicPids = cache.get(cacheKey);
+		if (topicPids) {
+			return topicPids.slice(index - 1);
+		}
+		const pids = await db[reverse ? 'getSortedSetRevRange' : 'getSortedSetRange'](topicSet, 0, -1);
+		cache.set(cacheKey, pids, 30000);
+		return pids.slice(index - 1);
+	}
+
+	async function getUserPids() {
+		const cid = await topics.getTopicField(data.tid, 'cid');
+		const cacheKey = `np:cid:${cid}:uid:${socket.uid}:pids`;
+		const userPids = cache.get(cacheKey);
+		if (userPids) {
+			return userPids;
+		}
+		const pids = await db.getSortedSetRange(`cid:${cid}:uid:${socket.uid}:pids`, 0, -1);
+		cache.set(cacheKey, pids, 30000);
+		return pids;
+	}
+
+	const [topicPids, userPidsInCategory] = await Promise.all([
+		getTopicPids(data.index),
+		getUserPids(),
+	]);
+	const userPidsInTopic = _.intersection(topicPids, userPidsInCategory);
+	if (!userPidsInTopic.length) {
+		return 0;
+	}
+	return await posts.getPidIndex(userPidsInTopic[0], data.tid, data.sort);
+};
+
+SocketTopics.getPostCountInTopic = async function (socket, tid) {
+	if (!socket.uid || !tid) {
+		return 0;
+	}
+	return await db.sortedSetScore(`tid:${tid}:posters`, socket.uid);
+};
+
 require('../promisify')(SocketTopics);