HTTP/2 301
server: nginx
date: Thu, 31 Jul 2025 00:18:36 GMT
content-type: text/html
content-length: 162
location: https://developer.mozilla.org/en-US/docs/Web/API/ToggleEvent
strict-transport-security: max-age=60; includeSubDomains
via: 1.1 google
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
HTTP/2 200
x-guploader-uploadid: ABgVH8_H5-N814XAWQRyfWHlquYo18xHu9xSCn2ymAvpz5eXpfQ0kTcpGzPYamLa6Wunf5miBRWO7Ak
x-goog-generation: 1753231587592359
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 56847
x-goog-meta-goog-reserved-file-mtime: 1753230316
x-goog-hash: crc32c=VE4yzw==, md5=Nu6yaI/7iuBb1hn2pD0Vng==
x-goog-storage-class: STANDARD
accept-ranges: none
expires: Thu, 31 Jul 2025 01:18:37 GMT
cache-control: public, max-age=3600
last-modified: Wed, 23 Jul 2025 00:46:27 GMT
etag: W/"36eeb2688ffb8ae05bd619f6a43d159e"
content-type: text/html
age: 0
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
alt-svc: clear
x-content-type-options: nosniff
strict-transport-security: max-age=63072000
content-security-policy: default-src 'self'; script-src 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-EehWlTYp7Bqy57gDeQttaWKp0ukTTEUKGP44h8GVeik=' 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M='; script-src-elem 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-EehWlTYp7Bqy57gDeQttaWKp0ukTTEUKGP44h8GVeik=' 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M='; style-src 'report-sample' 'self' 'unsafe-inline'; object-src 'none'; base-uri 'self'; connect-src 'self' developer.allizom.org bcd.developer.allizom.org bcd.developer.mozilla.org updates.developer.allizom.org updates.developer.mozilla.org https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://incoming.telemetry.mozilla.org https://observatory-api.mdn.allizom.net https://observatory-api.mdn.mozilla.net https://api.github.com/search/issues stats.g.doubleclick.net https://api.stripe.com; font-src 'self'; frame-src 'self' interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net mdn.github.io live-samples.mdn.mozilla.net live-samples.mdn.allizom.net *.mdnplay.dev *.mdnyalp.dev *.play.test.mdn.allizom.net https://v2.scrimba.com https://scrimba.com jsfiddle.net www.youtube-nocookie.com codepen.io survey.alchemer.com https://js.stripe.com; img-src 'self' data: *.githubusercontent.com *.googleusercontent.com *.gravatar.com mozillausercontent.com firefoxusercontent.com profile.stage.mozaws.net profile.accounts.firefox.com developer.mozilla.org mdn.dev interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net wikipedia.org upload.wikimedia.org https://mdn.github.io/shared-assets/ https://mdn.dev/ https://*.google-analytics.com https://*.googletagmanager.com www.gstatic.com; manifest-src 'self'; media-src 'self' archive.org videos.cdn.mozilla.net https://mdn.github.io/shared-assets/; child-src 'self'; worker-src 'self';
x-frame-options: DENY
origin-trial: AxVILwizhbMjxFeHOn1P3R8niO1RJY/smaK4B4d1rLzc1gTaxtXMSaTi+FoigYgCw40uFRDwFcEAeqDR+vVLOW4AAABfeyJvcmlnaW4iOiJodHRwczovL2RldmVsb3Blci5tb3ppbGxhLm9yZyIsImZlYXR1cmUiOiJQcml2YXRlQXR0cmlidXRpb25WMiIsImV4cGlyeSI6MTc0MjA3OTYwMH0=
x-cloud-trace-context: c81cf03f2ead26cd2d7596fa02d24218
date: Thu, 31 Jul 2025 00:18:37 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
ToggleEvent - Web APIs | MDN
ToggleEvent Baseline 2023
Newly available
The ToggleEvent
interface represents an event notifying the user an Element's state has changed.
This is the event object for the HTMLElement
beforetoggle
and toggle
events, which fire on some elements just before and just after they transition between showing and hidden, respectively.
Event
ToggleEvent
This interface inherits properties from its parent, Event
.
ToggleEvent.newState
Read only
A string (either "open"
or "closed"
), representing the state the element is transitioning to.
ToggleEvent.oldState
Read only
A string (either "open"
or "closed"
), representing the state the element is transitioning from.
const popover = document.getElementById("mypopover");
// …
popover.addEventListener("beforetoggle", (event) => {
if (event.newState === "open") {
console.log("Popover is being shown");
} else {
console.log("Popover is being hidden");
}
});