'bool HTTPClient::begin(String)' is deprecated

maxgerhardt · November 4, 2020, 5:42pm

~~It’s a warning, not an error.~~ Nevermind it’s marked as error through special GCC attributes.

The deprecation is clearly marked in the library code:

esp8266/Arduino/blob/5d2563eee98ae116dc3d4b6bc14225efb3c85098/libraries/ESP8266HTTPClient/src/ESP8266HTTPClient.h#L159-L167


      
          /*
           * Since both begin() functions take a reference to client as a parameter, you need to 
           * ensure the client object lives the entire time of the HTTPClient
           */
              bool begin(WiFiClient &client, const String& url);
              bool begin(WiFiClient &client, const String& host, uint16_t port, const String& uri = "/", bool https = false);
          
              // old API is now explicitely forbidden
              bool begin(String url)  __attribute__ ((error("obsolete API, use ::begin(WiFiClient, url)")));

To use the new API, rewrite

        HTTPClient http;
        http.begin(serverNameon);

to

        WiFiClient client;
        HTTPClient http;
        http.begin(client, serverNameon);

just like in the official example

github.com

esp8266/Arduino/blob/5d2563eee98ae116dc3d4b6bc14225efb3c85098/libraries/ESP8266HTTPClient/examples/BasicHttpClient/BasicHttpClient.ino#L39-L48


      
          void loop() {
            // wait for WiFi connection
            if ((WiFiMulti.run() == WL_CONNECTED)) {
          
              WiFiClient client;
          
              HTTPClient http;
          
              Serial.print("[HTTP] begin...\n");
              if (http.begin(client, "http://jigsaw.w3.org/HTTP/connection.html")) {  // HTTP