MutationObserver wrapper to wait for the specified CSS selector
Verzia zo dňa
Tento skript by nemal byť nainštalovaný priamo. Je to knižnica pre ďalšie skripty, ktorú by mali používať cez meta príkaz // @require https://update.greatest.deepsurf.us/scripts/12228/175122/setMutationHandler.js
// ==UserScript==
// @name setMutationHandler
// @description MutationObserver wrapper to wait for the specified CSS selector
// @namespace wOxxOm.scripts
// @author wOxxOm
// @grant none
// @version 3.0.2
// ==/UserScript==
function setMutationHandler(target, selector, handler, options) {
// or setMutationHandler(selector, handler, options) {
// or setMutationHandler(options) {
if (typeof arguments[0] == 'string') {
options = arguments[2] || {};
handler = arguments[1];
selector = arguments[0];
target = document;
} else if (arguments.length == 1 && target && typeof target.handler == 'function') {
options = arguments[0];
handler = options.handler;
selector = options.selector;
target = options.target || document;
} else if (!(target instanceof Node)) {
throw 'Bad params for setMutationHandler.\n' +
'A: [optional Node] target, [String] selector, [Function] handler, [optional Object] options\n' +
'B: [Object] options\n' +
'Options: target, selector, handler, processExisting, childList, attributes, characterData, subtree, attributeOldValue, characterDataOldValue, attributeFilter';
} else
options = options || {};
if (options.processExisting && target.querySelector(selector))
handler.call(null, Array.prototype.slice.call(target.querySelectorAll(selector)));
if (!options.attributes && !options.characterData && !options.childList && options.subtree === undefined)
options.childList = options.subtree = true;
var cb;
if (/^#[\w\d-]+$/.test(selector)) {
selector = selector.substr(1);
cb = MOhandlerForId;
} else {
cb = MOhandler;
}
var observer = new MutationObserver(cb);
observer.observe(target, options || {subtree:true, childList:true});
return observer;
function MOhandler(mutations) {
if (mutations.length > 100 && !document.querySelector(selector))
return;
var found = [];
for (var i=0, m; (m = mutations[i++]); ) {
switch (m.type) {
case 'childList':
var nodes = m.addedNodes, nl = nodes.length;
var textNodesOnly = true;
for (var j=0; j < nl; j++) {
var n = nodes[j];
textNodesOnly &= n.nodeType == 3; // TEXT_NODE
if (n.nodeType != 1) // ELEMENT_NODE
continue;
if (n.matches(selector))
found.push(n);
else if (n.querySelector(selector)) {
n = n.querySelectorAll(selector);
if (n.length < 1000)
found.push.apply(found, n);
else
found = found.concat(found.slice.call(n));
}
}
if (textNodesOnly && m.target.matches(selector))
found.push(m.target);
break;
case 'attributes':
if (m.target.matches(selector))
found.push(m.target);
break;
case 'characterData':
if (m.target.parentNode && m.target.parentNode.matches(selector))
found.push(m.target.parentNode);
break;
}
}
if (!found.length)
return;
if (handler.call(observer, found) === false)
observer.disconnect();
}
function MOhandlerForId(mutations) {
var el = document.getElementById(selector);
if (el && target.contains(el))
if (handler.call(observer, [el]) === false)
observer.disconnect();
}
}