Call configuration_key_changed_callback when set_custom_configuration_key finished successfully

include/ocpp/v16/charge_point.hpp

@@ -446,7 +446,8 @@ class ChargePoint {
         const std::function<void(const int32_t connector, const int32_t transaction_id)>& callback);
 
     /// \brief registers a \p callback function that can be used to react on changed configuration keys. This
-    /// callback is called when a configuration key has been changed by the CSMS
+    /// callback is called when a configuration key has been successfully changed by the CSMS or internally using the
+    /// set_custom_configuration_key function
     /// \param key the configuration key for which the callback is registered
     /// \param callback executed when this configuration key changed
     void register_configuration_key_changed_callback(const CiString<50>& key,

lib/ocpp/v16/charge_point_impl.cpp

@@ -3658,7 +3658,21 @@ GetConfigurationResponse ChargePointImpl::get_configuration_key(const GetConfigu
 }
 
 ConfigurationStatus ChargePointImpl::set_custom_configuration_key(CiString<50> key, CiString<500> value) {
-    return this->configuration->setCustomKey(key, value, true);
+    // attempt to set the custom key
+    const auto result = this->configuration->setCustomKey(key, value, true);
+    if (result != ConfigurationStatus::Accepted) {
+        // return immediately if not "Accepted"
+        return result;
+    }
+
+    // notify callback if registered and change was accepted
+    if (this->configuration_key_changed_callbacks.count(key) and
+        this->configuration_key_changed_callbacks[key] != nullptr and result == ConfigurationStatus::Accepted) {
+        KeyValue kv = {key, false, value};
+        this->configuration_key_changed_callbacks[key](kv);
+    }
+
+    return result;
 }
 
 } // namespace v16