HTMLMediaElement: loadstart event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Theloadstart event is fired when the browser has started to load a resource.
Syntax
Use the event name in methods likeaddEventListener(), or set an event handler property.
js
addEventListener("loadstart", (event) => { })onloadstart = (event) => { }Event type
A genericEvent.
Examples
Live example
HTML
html
<div> <button type="button">Load video</button> <video controls width="250"></video> <div> <label for="eventLog">Event log:</label> <textarea readonly></textarea> </div></div>.event-log-contents { width: 18rem; height: 5rem; border: 1px solid black; margin: 0.2rem; padding: 0.2rem;}.example { display: grid; grid-template-areas: "button log" "video log";}button { grid-area: button; width: 10rem; margin: 0.5rem 0;}video { grid-area: video;}.event-log { grid-area: log;}.event-log > label { display: block;}JavaScript
js
const loadVideo = document.querySelector("button");const video = document.querySelector("video");const eventLog = document.querySelector(".event-log-contents");let source = null;function handleEvent(event) { eventLog.textContent += `${event.type}\n`;}video.addEventListener("loadstart", handleEvent);video.addEventListener("progress", handleEvent);video.addEventListener("canplay", handleEvent);video.addEventListener("canplaythrough", handleEvent);loadVideo.addEventListener("click", () => { if (source) { document.location.reload(); } else { loadVideo.textContent = "Reset example"; source = document.createElement("source"); source.setAttribute("src", "/shared-assets/videos/flower.webm"); source.setAttribute("type", "video/webm"); video.appendChild(source); }});Result
Specifications
| Specification |
|---|
| HTML # event-media-loadstart |
| HTML # handler-onloadstart |