save & load json

[Koxx3]

Hello, thanks for your great tutorial. It's really good. I have an issue with the json load. It loads the json fine, but in another root... so, the rest of the app can't use it. is it a mistake ? if no, did I miss something ? if yes, how to fix it ? ;) Thanks !! Francois (greetings from france)

[Koxx3]

https://github.com/projetsdiy/ESP8266-Webserver-Tutorials/blob/master/Part5_DHT22WebserverESP8266_SPIFFS/Part5_DHT22WebserverESP8266_SPIFFS.ino first root at L60 second root at L197

clearly, the root scope isn't the same, and the json data is lost after exiting the function.

[Igor-from-moscow]

To solve this problem, I propose to replace the subprogram of the same name with the one below:

void loadHistory(){
  DynamicJsonBuffer json_Buffer(5000);   
  File file = SPIFFS.open(HISTORY_FILE, "r");
  if (!file){
    Serial.println("No History Exist");
  } else {
    size_t size = file.size();
    if ( size == 0 ) {
      Serial.println("History file empty !");
    } else {
      std::unique_ptr<char[]> buf (new char[size]);
      file.readBytes(buf.get(), size);
JsonObject &temp_root = json_Buffer.parseObject(buf.get());  //область видимости в этой подпрограмме только
      if (!temp_root.success()) {
        Serial.println("Impossible to read JSON file");
      } else {
        Serial.println("History loaded");
        temp_root.prettyPrintTo(Serial);
        Serial.println (" ");  
//---- заполнение рабочего JsonObject
        for (int i=0; i< temp_root["timestamp"].size(); i++){
          timestamp.add( long(temp_root["timestamp"][i]));
          hist_t.add(double(temp_root["t"][i]));
          hist_h.add(double(temp_root["h"][i]));
          hist_pa.add(double(temp_root["pa"][i]));
        }
        if (temp_root["bart"].size() > 0 ) {
          for ( int k = 0 ; k < 7 ; k++ ) { 
            bart.add(double(temp_root["bart"][k]));
            barh.add(double(temp_root["barh"][k]));
          }  
        } 
       }
      }
    file.close();
  }
}