Second Life Forums thread blocker

slforums_thread_blocker.js

// ==UserScript==
// @name         Thread blocker
// @namespace    http://felix.softhyena.com/
// @version      0.1
// @description  Block threads on the Second Life forums
// @author       Chaser Zaks
// @match        https://community.secondlife.com/forums/forum/*
// @grant        none
// ==/UserScript==

(function(){
    let showBlocked = Boolean(parseInt(localStorage.getItem("showBlocked") || 0));
    document.body.dataset.showBlockedThreads = showBlocked;

    //Create the stylesheet
    const style = document.createElement("style");
    style.textContent = `
body[data-show-blocked-threads="false"] ol.cTopicList > li[data-blocked="true"] {
    display: none;
};
`;
    document.head.append(style);

    //Create the toggle button
    const ipsBreadcrumb = document.querySelector("nav.ipsBreadcrumb > ul"),
        toggleLi = document.createElement("li"),
        toggleA = document.createElement("a"),
        toggleI = document.createElement("i"),
        toggleSpan = document.createElement("span");

    //Append children
    toggleLi.appendChild(toggleA);
    toggleA.appendChild(toggleI);
    toggleA.appendChild(toggleSpan);

    //Setup the anchor
    toggleA.setAttribute("class", ipsBreadcrumb.firstElementChild.firstElementChild.getAttribute("class"));
    toggleA.setAttribute("href", "#");

    //Setup the icon
    toggleI.setAttribute("aria-hidden", "true");
    toggleI.setAttribute("class", "fa fa-shield");

    //Setup the text
    toggleSpan.textContent = (showBlocked ? "Hide" : "Show") + " blocked threads";

    ipsBreadcrumb.insertBefore(toggleLi, ipsBreadcrumb.firstElementChild);

    toggleA.addEventListener("click", e=>{
        e.preventDefault();
        showBlocked = !showBlocked;
        localStorage.setItem("showBlocked", Number(showBlocked).toString());
        document.body.dataset.showBlockedThreads = showBlocked;
        toggleSpan.textContent = (showBlocked ? "Hide" : "Show") + " blocked threads";
    });

    //Process threads
    const threadTable = document.querySelector("ol.cTopicList");
    if(!threadTable) return; //Escape early if we can't find a valid topic list
    
    let blockedThreads = JSON.parse(localStorage.getItem("blockedThreads")) || [];
    for(let thread of threadTable.children){
        let blocked = blockedThreads.indexOf(parseInt(thread.dataset.rowid)) != -1;
        thread.dataset.blocked = blocked;

        //Add button to thread
        let buttonLocation = thread.querySelector("div.ipsDataItem_main > div.ipsDataItem_meta"),
            blockA = document.createElement("a"),
            blockI = document.createElement("i"),
            blockSpan = document.createElement("span");

        blockA.appendChild(blockI);
        blockA.appendChild(blockSpan);
        blockA.setAttribute("href", "#");
        blockI.setAttribute("aria-hidden", "true");
        blockI.setAttribute("class", "fa fa-shield");
        blockI.innerHTML = " ";
        blockSpan.textContent = (blocked ? "Unblock" : "Block") + " thread";

        //Add handler for button
        blockA.addEventListener("click", e=>{
            e.preventDefault();
            let blockedThreads = JSON.parse(localStorage.getItem("blockedThreads")) || [];

            //Resolve thread
            let thread = e.target;
            if(thread.tagName != "A") thread = thread.parentElement;

            let blockSpan = thread.querySelector("span");
            thread = thread.parentElement.parentElement.parentElement;

            let tid = parseInt(thread.dataset.rowid);

            //Handle blocking
            let blocked = blockedThreads.indexOf(tid) != -1;
            if(blocked){ //Blocked, so unblock it
                blockedThreads = blockedThreads.filter(item => item !== tid);
            }else{ //Not blocked, so block it.
                blockedThreads.push(tid);
            }
            blocked = !blocked;

            //Update and save
            thread.dataset.blocked = blocked;
            blockSpan.textContent = (blocked ? "Unblock" : "Block") + " thread";
            localStorage.setItem("blockedThreads", JSON.stringify(blockedThreads));
        });
        buttonLocation.appendChild(blockA);
    }
})();