102 Processing

PROPFIND /large-directory HTTP/1.1
Host: webdav.example.com
Depth: infinity

HTTP/1.1 102 Processing

[... 20 seconds later ...]

HTTP/1.1 207 Multi-Status
Content-Type: application/xml

<?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d="DAV:">...</d:multistatus>

const http = require('http');

const server = http.createServer((req, res) => {
  // Emitting an interim 102 response (legacy approach)
  res.writeProcessing(); // Note: Not a standard Node.js method, requires manual socket writing
  req.socket.write('HTTP/1.1 102 Processing\r\n\r\n');
  
  setTimeout(() => {
    res.writeHead(200);
    res.end('Processing complete');
  }, 10000);
});

# Python WSGI servers (like Gunicorn/uWSGI) and frameworks (Flask/Django) 
# generally do not support sending multiple status codes (102 followed by 200) 
# on a single synchronous connection. 
# The recommended approach in Python is a Celery background task and a 202 response.

@app.route('/long-task', methods=['POST'])
def long_task():
    task = process_data.delay()
    return jsonify({"task_id": task.id}), 202

package main

import (
	"net/http"
	"time"
)

func handler(w http.ResponseWriter, r *http.Request) {
	// Go allows hijacking the connection to write raw HTTP if strictly necessary
	hijacker, ok := w.(http.Hijacker)
	if ok {
		conn, _, _ := hijacker.Hijack()
		defer conn.Close()
		conn.Write([]byte("HTTP/1.1 102 Processing\r\n\r\n"))
		
		time.Sleep(10 * time.Second)
		conn.Write([]byte("HTTP/1.1 200 OK\r\nContent-Length: 2\r\n\r\nOK"))
	}
}

# curl handles 1xx informational responses automatically 
# and will wait for the final response without timing out.
curl -X PROPFIND -H "Depth: infinity" https://webdav.example.com/files/