// ==UserScript==
// @name           AO3: Go To to Latest Chapter
// @namespace      https://github.com/w4tchdoge
// @version        1.0.0-20241029_212556
// @description    Adds a link to the chapter navigation bar to go to the latest chapter of a work. Alternative method is to add `/latest` to the end of an AO3 work URL. e.g. https://archiveofourown.org/works/{AO3_WORK_ID}/chapters/{AO3_CHAPTER_ID}#workskin/latest
// @author         w4tchdoge
// @homepage       https://github.com/w4tchdoge/MISC-UserScripts
// @match          *://archiveofourown.org/*works/*
// @match          *://archiveofourown.org/*works/*/latest
// @exclude        *://archiveofourown.org/*works/*/bookmarks
// @exclude        *://archiveofourown.org/*works/*/navigate
// @license        AGPL-3.0-or-later
// @run-at         document-start
// @history        1.0.0 — Move the `latest_url` stuff to a function. Comment the code to the point where hopefully someone that doesn't know JS can understand what it's doing. Clean up old commented code that's no longer used. Add a description
// @history        0.0.1 — Initial commit
// ==/UserScript==
(async function () {
`use strict`;
// modified from https://stackoverflow.com/a/61511955/11750206
function waitForElm(selector, search_root = document) {
return new Promise(resolve => {
if (search_root.querySelector(selector)) {
return resolve(search_root.querySelector(selector));
}
const observer = new MutationObserver(mutations => {
if (search_root.querySelector(selector)) {
observer.disconnect();
resolve(search_root.querySelector(selector));
}
});
// If you get "parameter 1 is not of type 'Node'" error, see https://stackoverflow.com/a/77855838/492336
observer.observe(document.documentElement, {
childList: true,
subtree: true
});
});
}
// Gets URL of the latest chapter of a work
// Input is the work ID as a string
// Output is the latest URL as a URL object
async function getLatestURL(ao3_work_id) {
// Define the URL to be fetched
const fetch_url = `https://archiveofourown.org/works/${ao3_work_id}/navigate`;
// Fetch the URL as UTF-8 HTML and wait for the response from the server
const fetch_resp = await fetch(fetch_url, { headers: { 'Content-Type': 'text/html; charset=utf-8', } });
// Save the Response stream as a UTF-8 string
const resp_text = await fetch_resp.text();
// Create a new DOM parser
const html_parser = new DOMParser();
// Parse the response text as HTML and saves the output
const html = html_parser.parseFromString(resp_text, `text/html`);
// Search the parsed HTML of the navigate page for all links that go to a chapter
const chapter_links_arr = Array.from(html.querySelectorAll(`#main .chapter.index.group > li > a[href^="/works"]`));
// Get the href attribute of the last element in above array (which would be the latest chapter), and add the '#workskin' anchor that AO3 has for the buttons that take you to the next/prev chapter
const latest_ch_href = `${chapter_links_arr.at(-1).getAttribute(`href`)}#workskin`;
// Create a URL object from the latest chapter href
const latest_url = new URL(latest_ch_href, `https://archiveofourown.org`);
return latest_url;
}
// Get current page url as a URL object
const curr_url = new URL(window.location);
// Get AO3 work ID
const work_id = (() => {
// Split path of current URL on all forward slashes
const pathname_segments = curr_url.pathname.split(`/`);
// Get the index of the last element which is a string equal to 'works'
// Add 1 to it to get the index of the work ID
const wid_index = (pathname_segments.findLastIndex(elm => elm === `works`)) + 1;
// Get work ID using the above index
const wid = pathname_segments.at(wid_index);
return wid;
})();
// Check if URL ends in latest
if (curr_url.pathname.split(`/`).at(-1).toString().toLowerCase() == `latest`) { // If URL ends in latest
// Stop further loading of webpage
window.stop();
// Get URL for the latest chapter
const latest_url = await getLatestURL(work_id);
// console.log(`latest`, curr_url, work_id, latest_url);
// Redirect to latest chapter
window.location.replace(latest_url);
}
else { // If URL doesn't end in latest
// Wait for the main content of the webpage to be loaded into the DOM
const main = await waitForElm(`#main`);
// Get the navbar where all the chapter navigation buttons are
const work_nav_actions = main.querySelector(`.work.navigation.actions`);
// Check to see if this is the latest chapter by checking for the presense of the 'Next Chapter →' button
if (work_nav_actions.querySelector(`.chapter.next`)) { // If not on latest chapter
// Get URL for the latest chapter
const latest_url = await getLatestURL(work_id);
// Get next chapter elements
const next_chapter_elm_arr = Array.from(main.querySelectorAll(`li`)).filter(elm => elm.textContent === `Next Chapter →`);
// console.log(next_chapter_elm_arr);
// Create latest chapter element using the next chapter element as a base
const latest_chapter_elm = ((input_elm) => {
// Clone the node so the original stays unmodified
let base_elm = input_elm.cloneNode(true);
// Add the latest class to the button
base_elm.classList.add(`latest`);
// Get the actual link element present in the main element
let link = base_elm.querySelector(`a`);
// Set the href of the link element to the pathname of the URL to the latest chapter
link.setAttribute(`href`, latest_url.pathname);
// Set the text of the link to indicate the button goes to the latest chapter
link.textContent = `Latest ↠`;
return base_elm;
})(next_chapter_elm_arr[0]);
// console.log(latest_chapter_elm);
// Add latest chapter elm after the next chapter elms
next_chapter_elm_arr.forEach(element => {
// Clone the latest chapter element while adding it so it can be put in two separate places
element.after(latest_chapter_elm.cloneNode(true));
});
} else { console.log(`\nYou are already on the latest chapter.`); } // If on latest chapter
}
})();