Class DevHandler

scripts/dev_server.py:30–107

HTTP handler with SPA routing and optional hot reload support.

class DevHandler(http.server.SimpleHTTPRequestHandler):
    """HTTP handler with SPA routing and optional hot reload support."""
    
    def log_message(self, format, *args):
        pass  # Suppress logging
    
    def do_GET(self):
        global hot_reload_enabled
        
        # Handle SSE endpoint for hot reload
        if self.path == '/__hot_reload' and hot_reload_enabled:
            self.handle_sse()
            return
        
        path = self.translate_path(self.path)
        
        if os.path.isfile(path):
            if path.endswith('.html') and hot_reload_enabled:
                self.serve_html_with_reload(path)
            else:
                super().do_GET()
            return
        
        # SPA fallback
        self.path = '/index.html'
        index_path = self.translate_path(self.path)
        if os.path.isfile(index_path):
            if hot_reload_enabled:
                self.serve_html_with_reload(index_path)
            else:
                super().do_GET()
        else:
            self.send_error(404)
    
    def serve_html_with_reload(self, path):
        """Inject hot reload script into HTML."""
        try:
            with open(path, 'rb') as f:
                content = f.read()
            
            script = b'''<script>(function(){var k='__coi_scroll';if('scrollRestoration' in history)history.scrollRestoration='manual';var s=sessionStorage.getItem(k);if(s){sessionStorage.removeItem(k);var y=parseInt(s);var n=0;function r(){if(n++>30)return;window.scrollTo(0,y);if(Math.abs(window.scrollY-y)>1)setTimeout(r,60)}window.addEventListener('load',function(){requestAnimationFrame(r)});document.addEventListener('DOMContentLoaded',function(){requestAnimationFrame(r)})}var e=new EventSource('/__hot_reload');e.onmessage=function(m){if(m.data==='reload'){sessionStorage.setItem(k,window.scrollY||document.documentElement.scrollTop);location.reload()}};e.onerror=function(){console.log('[Coi] Reconnecting...')}})();</script></body>'''
            content = content.replace(b'</body>', script)
            
            self.send_response(200)
            self.send_header('Content-Type', 'text/html; charset=utf-8')
            self.send_header('Content-Length', len(content))
            self.send_header('Cache-Control', 'no-cache')
            self.end_headers()
            self.wfile.write(content)
        except Exception as e:
            self.send_error(500, str(e))
    
    def handle_sse(self):
        """Server-Sent Events for hot reload."""
        self.send_response(200)
        self.send_header('Content-Type', 'text/event-stream')
        self.send_header('Cache-Control', 'no-cache')
        self.send_header('Connection', 'keep-alive')