reddit blacklist. automatically hide any posts or comments with blacklisted text.

reddit_blacklist.js

/* Use an extension like "User Javascript and CSS" from the Chrome Web Store to load this JS. */
/* https://chrome.google.com/webstore/detail/user-javascript-and-css/nbhcbdghjpllgmfilhnhkllmkecfmpld */

const blacklist = [
    "stock", "bitcoin", "gamestop", "gme", "wallstreetbets", "wsb", "crypto"
]

window.addEventListener("load", () => {
    new UrlWatcher()
})

let uu, pp, cc
const postPageSelector = ".rpBJOHq2PR60pnwJlUyP0"
const postTextSelector = "h3"
const commentPageSelector = "._1YCqQVO-9r-Up6QPB9H6_4"
const commentTextSelector = "div[data-testid='comment']"

class PageWatcher {
    constructor(listSelector, textSelector) {
        pp = this
        this.listSelector = listSelector
        this.textSelector = textSelector
        this.list = undefined
        this.observer = undefined
        this.blacklist = blacklist
        this.blacklistRegex = new RegExp(blacklist.join("|"), "gi")
        this.counter = new Counter()
    }

    start() {
        this.list = document.querySelector(this.listSelector)
        if (!this.list) {return}
        this.observer = new MutationObserver((m)=>{
            this.update(m)
        })
        this.observer.observe(this.list, {childList: true})
        console.log("watcher started")
        this.checkExisting()
    }

    stop() {
        if (this.observer) {
            this.observer.disconnect()
            this.observer = undefined
            console.log("watcher stopped")
        }
    }
    update(mutations) {
        console.log("update called")
        for (const mutation of mutations) {
            for (const node of mutation.addedNodes) {
                const text = node.querySelector(this.textSelector)
                if (!text) {
                    continue
                }
                if (text.innerText) {
                    if (this.blacklistRegex.test(text.innerText)) {
                        console.log("watcher MATCH FOUND in observer")
                        node.style.display = "none"
                        this.counter.add()
                    }
                }
            }
        }
    }
    checkExisting() {
        for (let node of this.list.children) {
            const text = node.querySelector(this.textSelector)
            if (!text) {
                continue
            }
            if (text.innerText) {
                if (this.blacklistRegex.test(text.innerText)) {
                    console.log("watcher MATCH FOUND in existing")
                    node.style.display = "none"
                    this.counter.add()
                }
            }
        }
    }
}

class UrlWatcher {
    constructor() {
        uu = this
        this.currentUrl = undefined
        this.pageWatcher = undefined
        this.observer = new MutationObserver(()=>{
            this.onChange()
        })
        this.observer.observe(document.body, {childList: true})
        this.onChange()
    }
    onChange() {
        if (document.location.href === this.currentUrl) {return}
        this.currentUrl = document.location.href
        if (this.pageWatcher) {
            this.pageWatcher.stop()
            this.pageWatcher = undefined
        }
        if (this.currentUrl.includes("/comments/")) {
            console.log("comment page found")
            this.pageWatcher = new PageWatcher(commentPageSelector, commentTextSelector)
        } else {
            console.log("post page found")
            this.pageWatcher = new PageWatcher(postPageSelector, postTextSelector)
        }
        this.pageWatcher.start()
    }
}

class Counter {
    constructor() {
        cc = this
        this.counter = undefined
        this.i = 0
        this.lastI = -1
        this.reset()
    }

    setPlaceholder() {
        if (!this.counter) {
            this.counter = document.getElementById("header-search-bar")
            if (!this.counter) {return}
        }

        if (this.i !== this.lastI) {
            let p = `Search Reddit [${this.i}]`
            console.log(`setting placeholder to ${p}`)
            this.counter.placeholder = p
            this.lastI = this.i
        }
    }
    add() {
        this.i += 1
        this.setPlaceholder()
    }
    reset() {
        this.i = 0
        this.setPlaceholder()
    }
}