window.WritableStream
See: Web APIs - WritableStream
WritableStream(underlyingSink, strategy)
Creates a new WritableStream object wrapping the provided underlying sink.
Returns: WritableStream
| Param | Type | Description |
|---|---|---|
underlyingSink | Object | Defines how the constructred stream object will behave. |
underlyingSink.start(contorller) | function | Called immediately when the object is constructed. If this process is to be done asynchronously, it can return a promise to signal success or failure. The controller parameter passed to this method is a WritableStreamDefaultController. This can be used by the developer to control the stream during set up. |
underlyingSink.write(chunk,controller) | function | Called when a new chunk of data is ready to be written to the underlying sink. It can return a promise to signal success or failure of the write operation. The controller parameter passed to this method is a WritableStreamDefaultController. This method will be called only after previous writes have succeeded, and never after the stream is closed or aborted. |
underlyingSink.close(controller) | function | Called if the app signals that it has finished writing chunks to the stream. If this process is asynchronous, it can return a promise to signal success or failure. This method will be called only after all queued-up writes have succeeded. The controller parameter passed to this method is a WritableStreamDefaultController. |
strategy | Object | Defines a queuing strategy for the stream. |
strategy.highWaterMark | number | The total number of chunks that can be contained in the internal queue before backpressure is applied. |
strategy.size(chunk) | function | Indicates the size to use for each chunk, in bytes. |
locked : boolean
Indicate whether the WritableStream is locked.
abort(reason)
Aborts the stream, signalling that the producer can no longer successfully write to the stream and it's to be immediately moved to an error state, with any queued writes discarded.
Returns: Promise<void>
| Param | Type |
|---|---|
reason | * |
close()
Closes the stream.
Returns: Promise<void>
Throws:
TypeErrorthrown if the stream is locked.TypeErrorthrown if the stream is closed or closing.
getWriter()
Returns a new WritableStreamDefaultWriter object and locks the stream to that object. While the stream is locked, no other writer can be acquired until this one is released.
Returns: WritableStreamDefaultWriter