single static-content handler serving all assets

src/ESP32React/ESP32React.cpp

@@ -2,10 +2,75 @@
 
 #include "WWWData.h" // include auto-generated static web resources
 
+#include <string.h>
+
 static constexpr const char CACHE_CONTROL[] = "public,max-age=60";
 
+// Single static-content handler serving all assets embedded in WWWData.h.
+class StaticContentHandler : public AsyncWebHandler {
+  public:
+    bool canHandle(AsyncWebServerRequest * request) const override {
+        const auto method = request->method();
+        return method == HTTP_GET || method == HTTP_HEAD || method == HTTP_OPTIONS;
+    }
+
+    void handleRequest(AsyncWebServerRequest * request) override {
+        // OPTIONS is handled generically - the server-level CORS headers are
+        // attached via DefaultHeaders in ESP32React::begin().
+        if (request->method() == HTTP_OPTIONS) {
+            request->send(200);
+            return;
+        }
+
+        const char *     url   = request->url().c_str();
+        const WWWAsset * found = lookup(url);
+        const WWWAsset * asset = found ? found : index_asset();
+
+        if (asset == nullptr) {
+            request->send(404);
+            return;
+        }
+
+        // If the client already has this exact ETag, respond 304 Not Modified without sending the body.
+        const String & inm = request->header(asyncsrv::T_INM);
+        if (inm.length() != 0 && strcmp(inm.c_str(), asset->etag) == 0) {
+            request->send(304);
+            return;
+        }
+
+        AsyncWebServerResponse * response = request->beginResponse(200, asset->contentType, asset->content, asset->len);
+        response->addHeader(asyncsrv::T_Content_Encoding, asyncsrv::T_gzip, false);
+        response->addHeader(asyncsrv::T_ETag, asset->etag, false);
+        response->addHeader(asyncsrv::T_Cache_Control, CACHE_CONTROL, false);
+        request->send(response);
+    }
+
+  private:
+    // Exact-match lookup in the asset table
+    static const WWWAsset * lookup(const char * url) {
+        for (size_t i = 0; i < WWW_ASSETS_COUNT; i++) {
+            if (strcmp(WWW_ASSETS[i].uri, url) == 0) {
+                return &WWW_ASSETS[i];
+            }
+        }
+        return nullptr;
+    }
+
+    // Returns the /index.html asset, used as the SPA fallback for any GET
+    // that didn't match an embedded asset (React Router handles routing on
+    // the client side).
+    static const WWWAsset * index_asset() {
+        static const WWWAsset * cached = nullptr;
+        if (cached == nullptr) {
+            cached = lookup("/index.html");
+        }
+        return cached;
+    }
+};
+
 ESP32React::ESP32React(AsyncWebServer * server, FS * fs)
-    : _securitySettingsService(server, fs)
+    : _server(server)
+    , _securitySettingsService(server, fs)
     , _networkSettingsService(server, fs, &_securitySettingsService)
     , _wifiScanner(server, &_securitySettingsService)
     , _networkStatus(server, &_securitySettingsService)
@@ -17,50 +82,6 @@ ESP32React::ESP32React(AsyncWebServer * server, FS * fs)
     , _mqttSettingsService(server, fs, &_securitySettingsService)
     , _mqttStatus(server, &_mqttSettingsService, &_securitySettingsService)
     , _authenticationService(server, &_securitySettingsService) {
-    //
-    // Serve static web resources
-    //
-
-    ArRequestHandlerFunction indexHtmlHandler = nullptr;
-
-    WWWData::registerRoutes([server, &indexHtmlHandler](const char * uri, const String & contentType, const uint8_t * content, size_t len, const String & hash) {
-        String etag = "\"" + hash + "\""; // RFC9110: ETag must be enclosed in double quotes
-
-        ArRequestHandlerFunction requestHandler = [contentType, content, len, etag](AsyncWebServerRequest * request) {
-            if (request->header(asyncsrv::T_INM) == etag) {
-                request->send(304);
-                return;
-            }
-
-            AsyncWebServerResponse * response = request->beginResponse(200, contentType, content, len);
-            response->addHeader(asyncsrv::T_Content_Encoding, asyncsrv::T_gzip, false);
-            response->addHeader(asyncsrv::T_ETag, etag, false);
-            response->addHeader(asyncsrv::T_Cache_Control, CACHE_CONTROL, false);
-            request->send(response);
-        };
-
-        server->on(uri, HTTP_GET, requestHandler);
-
-        // Capture index.html handler to set onNotFound once after all routes are registered
-        if (strcmp(uri, "/index.html") == 0) {
-            indexHtmlHandler = requestHandler;
-        }
-    });
-
-    // Set onNotFound handler once after all routes are registered
-    // Serving non matching get requests with "/index.html"
-    // OPTIONS get a straight up 200 response
-    if (indexHtmlHandler != nullptr) {
-        server->onNotFound([indexHtmlHandler](AsyncWebServerRequest * request) {
-            if (request->method() == HTTP_GET) {
-                indexHtmlHandler(request);
-            } else if (request->method() == HTTP_OPTIONS) {
-                request->send(200);
-            } else {
-                request->send(404); // not found
-            }
-        });
-    }
 }
 
 void ESP32React::begin() {
@@ -78,10 +99,11 @@ void ESP32React::begin() {
     _ntpSettingsService.begin();
     _mqttSettingsService.begin();
     _securitySettingsService.begin();
+    _server->addHandler(new StaticContentHandler());
 }
 
 void ESP32React::loop() {
     _networkSettingsService.loop();
     _apSettingsService.loop();
     _mqttSettingsService.loop();
-}
+}

src/ESP32React/ESP32React.h

@@ -68,6 +68,7 @@ class ESP32React {
     }
 
   private:
+    AsyncWebServer *        _server;
     SecuritySettingsService _securitySettingsService;
     NetworkSettingsService  _networkSettingsService;
     WiFiScanner             _wifiScanner;