I am currently working on a project with ESP8266 (ESP-12E) and I need to store information in a json file (more convenient to access via the web interface and easier to manage than EEPROM for me).
My problem is the following: I'm using the latest version of ArduinoJSON (6), but I haven't seen many examples except on their site, and this code doesn't work for me :
void DeleteCycle(size_t idtodelete) {
File schedules = SPIFFS.open("/schedules.json", "r");
if(schedules && schedules.size()) {
DynamicJsonDocument schedulesjson(1300);
DeserializationError err = deserializeJson(schedulesjson, schedules);
Serial.println(err.c_str());
if (err) {
Serial.print(F("deserializeJson() failed with code "));
Serial.println(err.c_str());
}
else {
JsonArray array = schedulesjson.to<JsonArray>();
// array.remove(0);
serializeJson(array, Serial);
}
schedules.close();
}
else {
Serial.println("Failed to read file.");
}
}
I guess the problem is the JsonArray, it's empty ! But my JsonDocument is not, because if I do
JsonObject obj = schedulesjson[0];
String test = obj["name"];
Serial.println("Test : " + test);
I get the first key value (name) of my array at index 0
This is my first post on StackOverflow, I hope I did it right, thanks in advance for your help!
I answer myself because I found the solution to my problem: writing
schedulesjson.to<JsonArray>();
empties the json document, so you have to put it before
DeserializationError err = deserializeJson(schedulesjson, schedules);