syntax-fm-mark-finished-shows.user.js

// ==UserScript==
// @name         Syntax.FM - Mark Finished Shows
// @namespace    salembeats
// @version      1.4
// @description  UPDATE: Fix for episode URL formatting (episodes under 100 have leading zeroes in the URL).
// @author       Cuyler Stuwe (salembeats)
// @include      https://syntax.fm/*
// ==/UserScript==

const FINISHED_SHOW_STYLE = `
    opacity: 0.2;
`;

async function main() {

    const audioEl = document.querySelector("audio");
    const audioPlayerEl = audioEl.parentElement;
    const audioPlayerTitleEl = audioPlayerEl.querySelector(".player__title");

    const scrapeCurrentEpisodeNumber = () => audioPlayerTitleEl.innerText.match(/(?=\d+:)\d+/)[0];
    const formatNumberToEpisodeUrlFormat = number => (+number).toLocaleString("en-US", {minimumIntegerDigits: 3});
    const showLinkElForEpisode = episodeNumber => document.querySelector(`[href^="/show/${formatNumberToEpisodeUrlFormat(episodeNumber)}/"]`);
    const markShowAsFinished = episodeNumber => { showLinkElForEpisode(episodeNumber).style = FINISHED_SHOW_STYLE; };

    const storeShowAsFinished = episodeNumber => { localStorage[episodeNumber] = true; };

    audioEl.addEventListener("ended", e => {
        const endedEpisodeNumber = scrapeCurrentEpisodeNumber();
        storeShowAsFinished(endedEpisodeNumber);
        markShowAsFinished(endedEpisodeNumber);
    });

    const markAllStoredFinishedShowsAsSuch = () => {
        const allSavedKeys = Object.keys(localStorage);
        allSavedKeys.forEach(savedKey => Number.isInteger(+savedKey) && localStorage[savedKey] ? markShowAsFinished(savedKey) : (0));
    };

    markAllStoredFinishedShowsAsSuch();

}

main();

How To Install

1. Install Tampermonkey: https://chrome.google.com/webstore/detail/tampermonkey/dhdgffkkebhmkfjojejmpbldmpobfkfo?hl=en

2. Click Raw button in this Gist (currently toward the upper-right of GitHub Gist's interface):

How To Use

When a Syntax.FM podcast episode reaches its end, it will become semitransparent.

The status of episodes finished as a given user on a given device is persisted across page loads.

1.3:

Fix include path, so that the script always triggers when necessary.

1.4:

Fix for episode URL formatting (episodes under 100 have leading zeroes in the URL):