Enhance AsyncCallbackJsonWebHandler with regex support

examples/Json/Json.ino

@@ -100,6 +100,19 @@ void setup() {
     response->setLength();
     request->send(response);
   });
+
+
+#ifdef ASYNCWEBSERVER_REGEX
+  server.on("^\\/page\\/(\\d+)$", HTTP_POST, [](AsyncWebServerRequest *request, JsonVariant &json) {
+      String number = request->pathArg(0);
+      AsyncJsonResponse *response = new AsyncJsonResponse();
+      JsonObject root = response->getRoot().to<JsonObject>();
+      root["pageStr"] = number;
+      root["pageInt"] = number.toInt();
+      response->setLength();
+      request->send(response);
+  });
+#endif
 #endif
 
   server.begin();

platformio.ini

@@ -58,6 +58,7 @@ build_flags =
   ; -D TAG=\"core\"
   ; -D LOG_LOCAL_LEVEL=ESP_LOG_VERBOSE
   ; -D ASYNCWEBSERVER_LOG_DEBUG
+  ; -D ASYNCWEBSERVER_REGEX
 upload_protocol = esptool
 monitor_speed = 115200
 monitor_filters = esp32_exception_decoder, log2file

src/AsyncJson.cpp

@@ -116,14 +116,29 @@ AsyncCallbackJsonWebHandler::AsyncCallbackJsonWebHandler(const String &uri, ArJs
   : _uri(uri), _method(HTTP_GET | HTTP_POST | HTTP_PUT | HTTP_PATCH), _onRequest(onRequest), maxJsonBufferSize(maxJsonBufferSize), _maxContentLength(16384) {}
 #else
 AsyncCallbackJsonWebHandler::AsyncCallbackJsonWebHandler(const String &uri, ArJsonRequestHandlerFunction onRequest)
-  : _uri(uri), _method(HTTP_GET | HTTP_POST | HTTP_PUT | HTTP_PATCH), _onRequest(onRequest), _maxContentLength(16384) {}
+  : _uri(uri), _isRegex(uri.startsWith("^") && uri.endsWith("$")), _method(HTTP_GET | HTTP_POST | HTTP_PUT | HTTP_PATCH), _onRequest(onRequest), _maxContentLength(16384) {}
 #endif
 
 bool AsyncCallbackJsonWebHandler::canHandle(AsyncWebServerRequest *request) const {
   if (!_onRequest || !request->isHTTP() || !(_method & request->method())) {
     return false;
   }
 
+#ifdef ASYNCWEBSERVER_REGEX
+  if (_isRegex) {
+    std::regex pattern(_uri.c_str());
+    std::smatch matches;
+    std::string s(request->url().c_str());
+    if (std::regex_search(s, matches, pattern)) {
+      for (size_t i = 1; i < matches.size(); ++i) {  // start from 1
+        request->_addPathParam(matches[i].str().c_str());
+      }
+    } else {
+      return false;
+    }
+  } else
+#endif
+
   if (_uri.length() && (_uri != request->url() && !request->url().startsWith(_uri + "/"))) {
     return false;
   }

src/AsyncJson.h

@@ -87,8 +87,10 @@ class AsyncMessagePackResponse : public AsyncJsonResponse {
 // Body handler supporting both content types: JSON and MessagePack
 
 class AsyncCallbackJsonWebHandler : public AsyncWebHandler {
+private:
 protected:
   String _uri;
+  bool _isRegex;
   WebRequestMethodComposite _method;
   ArJsonRequestHandlerFunction _onRequest;
 #if ARDUINOJSON_VERSION_MAJOR == 6

src/ESPAsyncWebServer.h

@@ -220,6 +220,7 @@ class AsyncWebServerRequest {
   using FS = fs::FS;
   friend class AsyncWebServer;
   friend class AsyncCallbackWebHandler;
+  friend class AsyncCallbackJsonWebHandler;
   friend class AsyncFileResponse;
   friend class AsyncStaticWebHandler;