How to use serializeJson with client?

[piranha771]

I want to use ArduinoJson's serializeJson(doc, client);

Unfortunately QNEthenet's client is not recognized as a valid output stream despite it basically implements Print.

Is there a way to call this? I don't want to make a C-string buffer just because I don't know how to cast it, to make this work.

Additional Info: https://arduinojson.org/v7/tutorial/serialization/ Page 110

[ssilverman]

Since EthernetClient extends from Print, it should work. Can you come up with a small example and also show me the compile error you’re seeing? (I don’t know what you mean by “not recognized.”)

[piranha771]

Solved.

I'm using the EthernetWebServer library. server.client() returns the QNEthernet client:

inline qindesign::network::EthernetClient EthernetWebServer::client()

I was trying to use

    JsonDocument doc;
    doc["hello"] = "World";
    serializeJson(doc, server.client());

And got this error

no instance of overloaded function "serializeJson" matches the argument listC/C++(304)
WebServer.cpp(219, 5): argument types are: (ArduinoJson::V704J1::JsonDocument, qindesign::network::EthernetClient)

For some reason I had to write it this way:

    JsonDocument doc;
    doc["hello"] = "World";
    EthernetClient cl = server.client();
    serializeJson(doc, cl);

Is it due to the inline? This can be closed nonetheless. Thanks for this great lib!