Wait For Selector

Waits for selectors to match newly added nodes

Tento skript by nemal byť nainštalovaný priamo. Je to knižnica pre ďalšie skripty, ktorú by mali používať cez meta príkaz // @require https://update.greasyfork.org/scripts/432418/1192077/Wait%20For%20Selector.js 

// ==UserScript==
// @name         Wait For Selector
// @namespace    http://tampermonkey.net/
// @description  Waits for elements
// @author       Kumirei
// @include      *community.wanikani.com*
// @grant        none
// ==/UserScript==

;(function (wfs) {
    let version = '1.0.1'

    // Create new observer on body to monitor all DOM changes
    let observer = new MutationObserver(mutationHandler)
    observer.observe(document.getElementsByTagName('html')[0], { childList: true, subtree: true })

    // Interface for interacting with the library
    let interface = {
        version,
        observer: observer,
        wait: waitForSelector,
        unwait: unwaitID,
        waits: {},
        waitsByID: {},
        nextID: 0,
    }

    // Start
    installInterface()

    // Creates a new entry to search for whenever a new element is added to the DOM
    function waitForSelector(selector, callback) {
        if (!interface.waits[selector]) interface.waits[selector] = {}
        interface.waits[selector][interface.nextID] = callback
        interface.waitsByID[interface.nextID] = selector
        search(selector, true)
        return interface.nextID++
    }

    // Deletes a previously registered selector
    function unwaitID(ID) {
        delete interface.waits[interface.waitsByID[ID]][ID]
        delete interface.waitsByID[ID]
    }

    // Makes sure that the public interface is the newest version and the same as the local one
    function installInterface() {
        if (!wfs) window.wfs = interface
        else if (wfs.version < interface.version) {
            wfs.version = interface.version
            wfs.observer.disconnect()
            wfs.observer = interface.observer
            wfs.wait = interface.wait
            wfs.unwait = interface.unwait
        }
        interface = wfs || interface
    }

    // Waits until there has been more than 300 ms between mutations and then checks for new elements
    let lastMutationDate = 0 // Epoch of last mutation event
    let timeoutID = 0
    function mutationHandler(mutations) {
        let duration = Date.now() - lastMutationDate
        lastMutationDate = Date.now()
        if (duration < 300) {
            clearTimeout(timeoutID)
            timeoutID = setTimeout(() => {
                for (let selector in interface.waits) search(selector)
            }, 300)
        }
    }

    // Searches for the selector and calls the callback on the found elements
    function search(selector, all = false) {
        document.querySelectorAll(selector).forEach((e, i) => {
            let callbacks = Object.values(interface.waits[selector])
            if (all || !e.WFSFound || e.WFSFound == lastMutationDate) {
                for (let callback of callbacks) callback(e)
                e.WFSFound = lastMutationDate
            }
        })
    }
})(window.wfs)