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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Naming a Downloaded File/

Naming a Downloaded File

In this example, the modification of the Content-Disposition in the response headers achieves the modification of the downloaded file name according to the fileName parameter in the request URL. 
addEventListener('fetch', event => {
  event.passThroughOnException();
  event.respondWith(handleRequest(event.request));
});

async function handleRequest(request) {
  const url = new URL(request.url);
  const fileName = url.searchParams.get('fileName');

  const response = await fetch(request);

  // Evaluate the response status code and the search parameter
  if (response.status !== 200 || !fileName) {
    return response;
  }

  // Modify the Content-Disposition response header
  response.headers.append('Content-Disposition', `attachment; filename="${fileName}"`);
  return response;
}

Sample Preview

Enter a URL (such as https://example.com/origin.exe?fileName=modified.exe) that matches the trigger rule of edge function in the address bar of the browser on both the PC and mobile terminal to preview the example effect.




Related References

Runtime APIs: Fetch
Runtime APIs: Response