WritableStream: locked property

Baseline 2022

Newly available

Since June 2022, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Note: This feature is available in Web Workers.

The locked read-only property of the WritableStream interface returns a boolean indicating whether the WritableStream is locked to a writer.

Value

A boolean value indicating whether or not the writable stream is locked.

Examples

js
const writableStream = new WritableStream(
  {
    write(chunk) {
      // ...
    },
    close() {
      // ...
    },
    abort(err) {
      // ...
    },
  },
  queuingStrategy,
);

// ...

const writer = writableStream.getWriter();

writableStream.locked;
// should return true, as the stream has been locked to a writer

Specifications

Specification
Streams Standard
# ref-for-ws-locked②

Browser compatibility

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