Edge Developer Platform

Edge Functions
- Overview
- Getting Started
- Operation Guide
  - Function Management
  - Web Debugging
  - Function Trigger
  - Environment Variable
- 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
  - Example Overview
  - 301 Redirect
  - Obtaining Client URL Information
  - Customization Based on Client Geo Location
  - Obtaining Client Geo Location Information
  - Batch Redirect
  - 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

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));
});
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async function handleRequest(request) {
  const url = new URL(request.url);
  const fileName = url.searchParams.get('fileName');
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  const response = await fetch(request);
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  // 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.
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Related References           
﻿Runtime APIs: Fetch﻿
﻿Runtime APIs: Response﻿