ReadableStreamDefaultReader.md

ReadableStreamDefaultReader

Namespace: SpawnDev.SpawnJS.JSObjects
Inherits: SpawnJSObject
Source: JSObjects/ReadableStreamDefaultReader.cs
MDN Reference: ReadableStreamDefaultReader on MDN

The ReadableStreamDefaultReader interface of the Streams API represents a default reader that can be used to read stream data supplied from a network (such as a fetch request). https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamDefaultReader

Constructors

Signature	Description
ReadableStreamDefaultReader(SpawnJSObjectReference _ref)	Deserialization constructor

Properties

Property	Type	Access	Description
Closed	Task	get	Returns a Promise that fulfills when the stream closes, or rejects if the stream throws an error or the reader's lock is released. This property enables you to write code that responds to an end to the streaming process.

Methods

Method	Return Type	Description
Cancel()	Task	Returns a Promise that resolves when the stream is canceled. Calling this method signals a loss of interest in the stream by a consumer. The supplied reason argument will be given to the underlying source, which may or may not use it.
Read()	Task<ReadableStreamReaderReadResponse>	Returns a promise providing access to the next chunk in the stream's internal queue.
ReleaseLock()	void	Releases the reader's lock on the stream.

Examples

SpawnDev.SpawnJS Mapping Note: The JavaScript examples below show the standard Web API usage. In SpawnDev.SpawnJS, the same API is available with C# conventions:

• Properties and methods use PascalCase (e.g., readyState becomes ReadyState)
• Events use ActionEvent with +=/-= (e.g., addEventListener("click", fn) becomes OnClick += handler)
• Async methods return Task<T> instead of Promise<T>
• Objects should be disposed with using statements
• Access via JS.Get<ReadableStreamDefaultReader>(...) or constructor new ReadableStreamDefaultReader(...)

fetch("https://www.example.org/").then((response) => {
  const reader = response.body.getReader();
  const stream = new ReadableStream({
    start(controller) {
      // The following function handles each data chunk
      function push() {
        // "done" is a Boolean and value a "Uint8Array"
        return reader.read().then(({ done, value }) => {
          // Is there no more data to read?
          if (done) {
            // Tell the browser that we have finished sending data
            controller.close();
            return;
          }

          // Get the data and send it to the browser via the controller
          controller.enqueue(value);
          push();
        });
      }

      push();
    },
  });

  return new Response(stream, { headers: { "Content-Type": "text/html" } });
});

See full example on MDN