This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2022.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The query() method of the LockManager interface returns a Promise that resolves with an object containing information about held and pending locks.
query()
None.
A Promise that resolves with an object containing a snapshot of the LockManager state. The object has the following properties:
heldAn array of LockInfo objects for held locks.
pendingAn array of LockInfo objects for pending lock requests.
The LockInfo object can have the following properties:
nameThe name passed to LockManager.request() when the lock was requested.
modeThe access mode passed to LockManager.request() when the lock was requested. The mode is either "exclusive" or "shared".
clientIdThe unique identity of the context where LockManager.request() is called. This is the same value as Client.id.
This method may return a promise rejected with a DOMException of one of the following types:
InvalidStateError DOMException
Thrown if the environments document is not fully active.
SecurityError DOMException
Thrown if a lock manager cannot be obtained for the current environment.
const state = await navigator.locks.query();
for (const lock of state.held) {
console.log(`held lock: name ${lock.name}, mode ${lock.mode}`);
}
for (const request of state.pending) {
console.log(`requested lock: name ${request.name}, mode ${request.mode}`);
}
| Specification |
|---|
| Web Locks API> # api-lock-manager-query> |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
query |
69 | 79 | 96 | 56 | 15.4 | 69 | 96 | 48 | 15.4 | 10.0 | 69 | 15.4 |
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https://developer.mozilla.org/en-US/docs/Web/API/LockManager/query