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.
The loadstart event is fired when the browser has started to load a resource.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
js
addEventListener("loadstart", (event) => { })
onloadstart = (event) => { }
Event type
A generic Event.
Examples
Live example
HTML
html
<div class="example">
<button type="button">Load video</button>
<video controls width="250"></video>
<div class="event-log">
<label for="eventLog">Event log:</label>
<textarea readonly class="event-log-contents" id="eventLog"></textarea>
</div>
</div>
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 |
Browser compatibility
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