// ==UserScript==
// @name         WaitForKeyElements3
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Find the specified element and execute subsequent code after finding it.
// @author       Zero
// @grant        none
// ==/UserScript==
// Example usage:
// waitForKeyElements("div.comments", {"textContent":"xxx"}, commentCallbackFunction);
// function commentCallbackFunction(node) {
//     node.textContent = "This comment changed by waitForKeyElements().";
// }
function waitForKeyElements(
selectorTxt,    // Required: The CSS selector string that specifies the desired element(s).
actionFunction, // Required: The code to run when elements are found. It is passed the matched element.
attributeFilter,// Optional: Filter the element by target attribute(s).
bWaitOnce,      // Optional: If false, will continue to scan for new elements even after the first match is found.
iframeSelector  // Optional: If set, identifies the iframe to search.
) {
var targetNodes, btargetsFound = false;
function querySelectorAllInIframe(iframe, selector) {
var doc = iframe.contentDocument || iframe.contentWindow.document;
return doc.querySelectorAll(selector);
}
if (typeof iframeSelector !== "undefined") {
var iframe = document.querySelector(iframeSelector);
if (iframe) {
targetNodes = querySelectorAllInIframe(iframe, selectorTxt);
}
} else {
targetNodes = document.querySelectorAll(selectorTxt);
}
if (targetNodes && targetNodes.length > 0) {
btargetsFound = true;
// Found target node(s). Go through each and act if they are new.
targetNodes.forEach(function (node) {
if (attributeFilter){
for (let attr of Object.keys(attributeFilter)){
if(node[attr] != attributeFilter[attr]){
return ;
}
}
}
var alreadyFound = node.dataset.alreadyFound || false;
if (!alreadyFound) {
// Call the payload function.
var cancelFound = actionFunction ? actionFunction(node) : console.log(node);
if (cancelFound) {
btargetsFound = false;
} else {
node.dataset.alreadyFound = true;
}
}
});
}
// Get the timer-control variable for this selector.
var controlObj = waitForKeyElements.controlObj || {};
var controlKey = selectorTxt.replace(/[^\w]/g, "_");
var timeControl = controlObj[controlKey];
// Now set or clear the timer as appropriate.
if (btargetsFound && bWaitOnce && timeControl) {
// The only condition where we need to clear the timer.
clearInterval(timeControl);
delete controlObj[controlKey];
} else {
// Set a timer, if needed.
if (!timeControl) {
timeControl = setInterval(function () {
waitForKeyElements(selectorTxt, actionFunction, attributeFilter, bWaitOnce, iframeSelector);
}, 300);
controlObj[controlKey] = timeControl;
}
}
waitForKeyElements.controlObj = controlObj;
};