Run results for: event delegation (with parent identification) vs local handlers

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Mobile Safari/537.36 EdgA/131.0.0.0

Browser: Chrome Mobile 131

Operating system: Android

Device Platform: Mobile

Date tested: 4 months ago

Test name	Executions per second
manyDel	2884.0 Ops/sec
manyLoc	20183.2 Ops/sec

HTML Preparation code:

<ul class='one'>
</ul>

<ul class='manyDel'>
</ul>

<ul class='manyLoc'>
</ul>

<template class='content'>
  <li data-x='2'>
    <div>
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      	<a class='link'></a>
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</template>

Script Preparation code:

var templ = document.querySelector(`.content`);

var manyDel = document.querySelector(`.manyDel`);
var manyDelLinks = [];

var manyLoc = document.querySelector(`.manyLoc`);
var manyLocLinks = [];

var x = 0;
function handleEvent(li) {
  x += (li.dataset.x|0);
}

function delHandleEvent(ev) {
  let li = ev.target;
  while (li.tagName !== `LI`) {li = li.parentElement;};
  handleEvent(li);
}

var n = 1000;
for (let i = 0; i < n; ++i) {
  let frag = templ.cloneNode(true).content;
  manyDelLinks.push(frag.querySelector(`.link`));
  manyDel.append(frag);
  
  frag = templ.cloneNode(true).content;
  let li = frag.firstElementChild;
  frag.querySelector(`.link`).addEventListener(`test`, () => handleEvent(li));
  manyLocLinks.push(frag.querySelector(`.link`));
  manyLoc.append(frag);
}

manyDel.addEventListener(`test`, handleEvent);

Tests:

manyDel
manyDelLinks[(Math.random() * n)|0].dispatchEvent(new CustomEvent(`test`, {bubbles : true}));
manyLoc
manyLocLinks[(Math.random() * n)|0].dispatchEvent(new CustomEvent(`test`, {bubbles : true}));