Cant send response onRequestBodyfrom

[phoenixofhp]

• ESP32 Arduino Core version: 3.07 based on ESP-IDF v5.1.4+
• Which board: ESP32-WROOM-32D
• Which platform (ESP8266, ESP32): ESP32
• AsyncTCP version (if applicable): 3.3.2
• AsyncTCP repository location you use (if applicable and if you use one coming from elsewhere): https://github.com/mathieucarbou/AsyncTCP
• Do you use AsyncTCPSock (y/n): n

Cant send response from onRequestBodyfrom

  server.onRequestBody([](AsyncWebServerRequest *request, uint8_t *data, size_t len, size_t index, size_t total){
      if (request->url() == "/game_log" && request->method() == HTTP_POST) {
          handleGameLog(request, data, len);
      }
  });

void handleGameLog(AsyncWebServerRequest *request, uint8_t *data, size_t len) {
    String body = "";
    body.reserve(len);
    
    for (size_t i = 0; i < len; i++) {
        body += (char)data[i];
    }

    JsonDocument doc;
    DeserializationError error = deserializeJson(doc, body);
    if (error) {
        Serial.println(error.c_str());
        request->send(400, "application/json", "{\"error\":\"Bad format JSON.\"}");
        return;
    }

    String game = doc["game"] | "";
    String token = doc["token"] | "";
    String result = doc["result"] | "";
    String time = doc["time"] | "";
    String name = doc["name"] | "";

    if (game.isEmpty() || token.isEmpty() || result.isEmpty() || time.isEmpty() || name.isEmpty()) {
        request->send(400, "application/json", "{\"error\":\"Not enough data\"}");
        return;
    }

    if (!validateAndRemoveToken(token, game)) {
        request->send(401, "application/json", "{\"error\":\"Bad token.\"}");
        return;
    }

  /* Some logic */

    request->send(200, "application/json", "{\"status\":\"OK\"}");
}

PS > curl -X POST http://10.10.32.190/game_log -H "Content-Type: application/json" -d '{"game": "test","token": "5d59f64be4888f7e","result": "win","time": "120"}'
PS >

[mathieucarbou]

I can reproduce... Looking... Weird that onNotFound works but not the other one.

[mathieucarbou]

@phoenixofhp : I understand what is happening.

onRequestBody and onRequestUpload are called during the request parsing phase: onBody for json post like you do for example and onUpload for file uploads.

but the request processing is really done by the onRequst handler, which, in your case, is the onNotFound.

It works exactly the the on(...) methods.

So you need to declare the onError like this:

  server.onNotFound([](AsyncWebServerRequest* request) {
    if (request->url() == "/game_log")
      return; // response object already created by onRequestBody

    request->send(404, "text/plain", "Not found");
  });

I will update SimpleServer.ino.

So no issue ;-)

[phoenixofhp]

Works like a charm. Thank you!
However, I don’t fully understand what happens without adding an onNotFound handler, even after reading the Request Life Cycle section.
Am I correct in assuming that a Response object WILL NOT be created at all unless the associated on method is invoked?

[mathieucarbou]

a response object is created as soon as send() is called, but the response object is kept in the request object until the end of the request parsing and the completion of the middleware chain. The sending over the network happens at the end.

So here, you are preparing a response while the request is being parsed (body section of the request). Pays attention that this is brittle because if you happen to receive a big payload, it can be split into 2 calls of onRequestBody! This is streaming here.

So then, the final handler processing the request is called (onNotFound).

In theory you should not do things like that, You should accumulate what you receive in the onRequestBody in a tmpObject in the request (there are examples of that). Then, in the final handler, you process the parsed object and create the json response.

What you do will fail at one point if someone sends a big payload.