Edge Developer Platform
  • Edge Functions
    • Overview
    • Getting Started
    • Operation Guide
      • Function Management
      • Function Trigger
    • Runtime APIs
      • addEventListener
      • Cache
      • Cookies
      • Encoding
      • Fetch
      • FetchEvent
      • Headers
      • Request
      • Response
      • Streams
        • ReadableStream
        • ReadableStreamBYOBReader
        • ReadableStreamDefaultReader
        • TransformStream
        • WritableStream
        • WritableStreamDefaultWriter
      • Web Crypto
      • Web standards
      • Images
        • ImageProperties
    • Sample Functions
      • Returning an HTML Page
      • Returning a JSON Object
      • Fetch Remote Resources
      • Authenticating a Request Header
      • Modifying a Response Header
      • Performing an A/B Test
      • Setting Cookies
      • Performing Redirect Based on the Request Location
      • Using the Cache API
      • Caching POST Requests
      • Responding in Streaming Mode
      • Merging Resources and Responding in Streaming Mode
      • Protecting Data from Tampering
      • Rewriting a m3u8 File and Configuring Authentication
      • Adaptive Image Resize
      • Image Adaptive WebP
      • Customize Referer restriction rules
      • Remote Authentication
      • HMAC Digital Signature
      • Naming a Downloaded File
      • Obtaining Client IP Address
    • Best Practices
      • Adaptive Image Format Conversion via Edge Functions
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Responding in Streaming Mode/

Responding in Streaming Mode

In this example, the Fetch API is called to fetch a remote jQuery.js resource, and the resource is sent to a client in streaming mode in response to a request from the client.

Sample Code

async function handleRequest(request) {
  const response = await fetch('https://static.cloudcachetci.com/qcloud/main/scripts/release/common/vendors/jquery-3.2.1.min.js');

  if (response.status !== 200) {
    return response;
  }

  // Generate readable streams and writeable streams.
  const { readable, writable } = new TransformStream();
  // Respond to the client in streaming mode.
  response.body.pipeTo(writable);

  return new Response(readable, response);
}

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request));
});

Sample Preview

In the address bar of the browser, enter a URL that matches a trigger rule of the edge function to preview the effect of the sample code.


References

Runtime APIs: TransformStream
Runtime APIs: Response