Parsing/ Deserializing JSON

[garymansted]

Hi there,
I was wondering if you could give me a tip at what id need to do to deserialize the following JSON.
Im trying to access the values but am having trouble. I read through the docs and the went through the examples but still having trouble understanding what I'd need to do. Any help greatly appreicated! BTW awesome library!

FirebaseJson json; 
FirebaseJsonData result;
json.setJsonData(fbObject.stringData());
json.toString(Serial, true);
Serial.println(json.raw());
 

{
    "-N0nOiQW93Qwmrak4Zo4": "2472",
    "-N0nOjhQjiTsJh30nX3L": "7158",
    "-N11tLabkdx7h1-1g5aj": "0721",
    "master": "7777"} {"-N0nOiQW93Qwmrak4Zo4":"2472","-N0nOjhQjiTsJh30nX3L":"7158","-N11tLabkdx7h1-1g5aj":"0721","master":"7777"}


json.get(result, "???");

[mobizt]

You also can cast the Json object from the FirebaseData like this

FirebaseJson json = fbObject.to<FirebaseJson>();

To deserialize

// parse with known key
json.get(result, "-N0nOiQW93Qwmrak4Zo4");

if (result.success)
{
  if (result.typeNum == FirebaseJson::JSON_STRING)
  {
     Serial.println(result.stringValue);
  }
  else if (result.typeNum == FirebaseJson::JSON_INT)
  {
     Serial.println(result.intValue);
  }
}

// or iterate all elements
size_t len = json.iteratorBegin();
FirebaseJson::IteratorValue value;
for (size_t i = 0; i < len; i++)
{
      value = json.valueAt(i);
      Serial.printf((const char *)FPSTR("%d, Name: %s, Value: %s\n"), i, value.key.c_str(), value.value.c_str());
}
json.iteratorEnd();

You can see how to handle FirebaseData from the RTDBHelper.h which included in all RTDB examples.

Firebase-ESP8266/src/addons/RTDBHelper.h

Lines 24 to 130 in 1373b01

	void printResult(FirebaseData &data)
	{
	if (data.dataTypeEnum() == fb_esp_rtdb_data_type_integer)
	Serial.println(data.to<int>());
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_float)
	Serial.println(data.to<float>(), 5);
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_double)
	printf("%.9lf\n", data.to<double>());
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_boolean)
	Serial.println(data.to<bool>() == 1 ? (const char *)FPSTR("true") : (const char *)FPSTR("false"));
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_string)
	Serial.println(data.to<String>());
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_json)
	{
	FirebaseJson *json = data.to<FirebaseJson *>();
	// Print all object data
	Serial.println((const char *)FPSTR("Pretty printed JSON data:"));
	json->toString(Serial, true);
	Serial.println();
	Serial.println((const char *)FPSTR("Iterate JSON data:"));
	Serial.println();
	size_t len = json->iteratorBegin();
	FirebaseJson::IteratorValue value;
	for (size_t i = 0; i < len; i++)
	{
	value = json->valueAt(i);
	Serial_Printf((const char *)FPSTR("%d, Type: %s, Name: %s, Value: %s\n"), i, value.type == FirebaseJson::JSON_OBJECT ? (const char *)FPSTR("object") : (const char *)FPSTR("array"), value.key.c_str(), value.value.c_str());
	}
	json->iteratorEnd();
	json->clear();
	}
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_array)
	{
	// get array data from FirebaseData using FirebaseJsonArray object
	FirebaseJsonArray *arr = data.to<FirebaseJsonArray *>();
	// Print all array values
	Serial.println((const char *)FPSTR("Pretty printed Array:"));
	arr->toString(Serial, true);
	Serial.println();
	Serial.println((const char *)FPSTR("Iterate array values:"));
	Serial.println();
	for (size_t i = 0; i < arr->size(); i++)
	{
	Serial.print(i);
	Serial.print((const char *)FPSTR(", Value: "));
	FirebaseJsonData result;
	// Get the result data from FirebaseJsonArray object
	arr->get(result, i);
	if (result.typeNum == FirebaseJson::JSON_BOOL)
	Serial.println(result.to<bool>() ? (const char *)FPSTR("true") : (const char *)FPSTR("false"));
	else if (result.typeNum == FirebaseJson::JSON_INT)
	Serial.println(result.to<int>());
	else if (result.typeNum == FirebaseJson::JSON_FLOAT)
	Serial.println(result.to<float>());
	else if (result.typeNum == FirebaseJson::JSON_DOUBLE)
	printf("%.9lf\n", result.to<double>());
	else if (result.typeNum == FirebaseJson::JSON_STRING ||
	result.typeNum == FirebaseJson::JSON_NULL ||
	result.typeNum == FirebaseJson::JSON_OBJECT ||
	result.typeNum == FirebaseJson::JSON_ARRAY)
	Serial.println(result.to<String>());
	}
	arr->clear();
	}
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_blob)
	{
	MB_VECTOR<uint8_t> *blob = data.to<MB_VECTOR<uint8_t> *>();
	for (size_t i = 0; i < blob->size(); i++)
	{
	if (i > 0 && i % 16 == 0)
	Serial.println();
	if ((*blob)[i] < 16)
	Serial.print((const char *)FPSTR("0"));
	Serial.print((*blob)[i], HEX);
	Serial.print((const char *)FPSTR(" "));
	}
	Serial.println();
	}
	else if (data.dataTypeEnum() == fb_esp_rtdb_data_type_file)
	{
	#if defined(FLASH_FS)
	File file = data.to<File>();
	int i = 0;
	while (file.available())
	{
	if (i > 0 && i % 16 == 0)
	Serial.println();
	int v = file.read();
	if (v < 16)
	Serial.print((const char *)FPSTR("0"));
	Serial.print(v, HEX);
	Serial.print((const char *)FPSTR(" "));
	i++;
	}
	Serial.println();
	file.close();
	#endif
	}
	else
	{
	Serial.println(data.payload());
	}
	}

The FirebaseJson examples are available in examples folder too.

[garymansted]

Thankyou sooooo much for taking the time to help me out!! I understand it now :) Once again awesome library!