Thingsboard Arduino Client Library issues - arduino

Question

So I've been working on modifying the thingsboard arduino library to support device provisioning. I've duplicated/renamed/modified a handful of functions in the library to support pointing to the correct topics, and added the supporting code in my main application to make use of them. However, I am now getting a compiler error in a section of the library code I did not touch. I'm hoping someone can point out what I goofed up, as it appears like it should be a fairly simple fix if I can find it.
This is the bit of code giving me the error-
inline Telemetry(const char *key, T val)
:m_type(TYPE_INT), m_key(key), m_value() { m_value.integer = val; }
Here is the error -
In file included from src\main.cpp:12:0:
.pio\libdeps\win\ThingsBoard\src/ThingsBoard.h: In instantiation of 'Telemetry::Telemetry(const char*, T) [with T = String; <template-parameter-1-2> = ArduinoJson6172_91::enable_if<false, void>]':
src\main.cpp:514:33: required from here
.pio\libdeps\win\ThingsBoard\src/ThingsBoard.h:46:64: error: cannot convert 'String' to 'int' in assignment
:m_type(TYPE_INT), m_key(key), m_value() { m_value.integer = val; }
Here's the bulk of what I added to my main code to handle device registration.
RPC_Response processDeviceRegistration(const RPC_Data &data)
{
Serial.println("Received the device registration response");
if(data["status"]=="SUCCESS"){
String credential = data["credentialsValue"];
EEPROM.write(10, sizeof(credential));
EEPROM.writeString(20, (String)credential);
dr.DR_Unsubscribe();
return RPC_Response("registration response", true);
}
else{
Serial.println("Device registration failed");
return RPC_Response("registration response", false);
}
}
const size_t callbacks_size = 2;
RPC_Callback callbacks[callbacks_size] = {
{ "device_registration", processDeviceRegistration }
};
void reinitialize()
{
if (!dr.RPC_Subscribe(callbacks, 1)) {
Serial.println("Failed to subscribe for RPC");
return;
}
dr.loop();
String IMEI = modem.getIMEI();
const int data_items = 3;
Telemetry data[data_items] = {
Telemetry("deviceName", IMEI),
Telemetry("provisionDeviceKey", provision_device_key),
Telemetry("provisionDeviceSecret", provision_device_secret),
};
if (!dr.sendDR(data, data_items)){
Serial.println("Device registration send failed");
}
If it would be helpful, I can fork and upload the full library code and post a link to my github.
----- Edit -----
Upon further investigation, it appears the template for the Telemetry class is detecting the IMEI variable as an integer rather than a string and trying to convert it for some reason. I have no idea why, or how to fix it. Any suggestions would be greatly appreciated.

Answer 1

Well then, helps if I take a few minutes to actually understand the code I didn't write that is giving me grief. There was no handler in the Telemetry constructor for a character array or string type variable. Added that and now everything is working :)
Full Telemetry constructor below -
inline Telemetry()
:m_type(TYPE_NONE), m_key(NULL), m_value() { }
// Constructs telemetry record from integer value.
// EnableIf trick is required to overcome ambiguous float/integer conversion
template<
typename T,
typename = ARDUINOJSON_NAMESPACE::enable_if<ARDUINOJSON_NAMESPACE::is_integral<T>::value>
>
inline Telemetry(const char *key, T val)
:m_type(TYPE_INT), m_key(key), m_value() { m_value.integer = val; }
// Constructs telemetry record from boolean value.
inline Telemetry(const char *key, bool val)
:m_type(TYPE_BOOL), m_key(key), m_value() { m_value.boolean = val; }
// Constructs telemetry record from float value.
inline Telemetry(const char *key, float val)
:m_type(TYPE_REAL), m_key(key), m_value() { m_value.real = val; }
// Constructs telemetry record from string value.
inline Telemetry(const char *key, const char *val)
:m_type(TYPE_STR), m_key(key), m_value() { m_value.str = val; }
// Constructs telemetry record from string value.
inline Telemetry(const char *key, char *val)
:m_type(TYPE_STR), m_key(key), m_value() { m_value.str = val; }