config_json_file

void loadConfig()
{
 if (SPIFFS.exists("/config.json"))
 {
  //file exists, reading and loading
  Serial.println("reading config file");
  File configFile = SPIFFS.open("/config.json", "r");
  if (configFile)
  {
   Serial.println("opened config file");
   size_t size = configFile.size();
   // Allocate a buffer to store contents of the file.
   std::unique_ptr<char[]> buf(new char[size]);

   configFile.readBytes(buf.get(), size);
   DynamicJsonBuffer jsonBuffer;
   JsonObject& json = jsonBuffer.parseObject(buf.get());
   // json.printTo(Serial); // print to serial the json file
   if (json.success())
   {
    PlantS1 = json["TargetSoilPlant1"];
    PlantS2 = json["TargetSoilPlant2"];
    PlantS3 = json["TargetSoilPlant3"];
    PlantS4 = json["TargetSoilPlant4"];
   }
   else{ Serial.println("failed to load json config"); }
  }
  else{ Serial.println("Failed to open config file"); }
  configFile.close();
  Serial.print("TargetSoilPlant1 :");Serial.println(PlantS1);
  Serial.print("TargetSoilPlant2 :");Serial.println(PlantS2);
  Serial.print("TargetSoilPlant3 :");Serial.println(PlantS3);
  Serial.print("TargetSoilPlant4 :");Serial.println(PlantS4);
 }
 else{ Serial.println("The JSON file doesn't exist "); }
}

void saveConfig()
{
 if (SPIFFS.exists("/config.json"))
 {
  //file exists, Saving configuration
  Serial.println("saving config");
  DynamicJsonBuffer jsonBuffer;
  JsonObject& json = jsonBuffer.createObject();
  json["TargetSoilPlant1"] = PlantS1;
  json["TargetSoilPlant2"] = PlantS2;
  json["TargetSoilPlant3"] = PlantS3;
  json["TargetSoilPlant4"] = PlantS4;

  File configFile = SPIFFS.open("/config.json", "w");
  if (!configFile) { Serial.println("failed to open config file for writing"); }
  // json.prettyPrintTo(Serial);
  json.printTo(configFile);

  if (json.printTo(configFile) == 0)
   { Serial.println(F("Failed to write to file")); }
  configFile.close();
  //end save
 }
 else{ Serial.println("The JSON file doesn't exist "); }
}