use same Builder for sensor specific fields

gateway/include/devices.h

@@ -18,6 +18,7 @@ struct OilTankRoomSensorBuilder {
             ->withParent(gatewayDevice);
         return Builder<TemperatureSensor>::instance(id)
             .asDevice(device)
+            .withValueTemplate("{{ value_json.sensor.temperature }}")
             .withDiagnostic(new VoltageSensor{id, "Battery voltage", "{{ value_json.sensor.diagnostic.voltage }}"})
             .withDiagnostic(new BatterySensor{id, "Battery level", "{{ ((states('sensor.oil_tank_room_battery_voltage')|float-2.5)|round(2)*100/2)|int }}"})
             .build();

gateway/include/ha.h

@@ -145,6 +145,21 @@ namespace Ha {
             return static_cast<T*>(cmp);
         }
 
+        Builder& withDeviceClass(const char* value) {
+            cmp->deviceClass = value;
+            return *this;
+        }
+
+        Builder& withUnitMseasure(const char* value) {
+            cmp->unitMeasure = value;
+            return *this;
+        }
+
+        Builder& withValueTemplate(const char* value) {
+            cmp->valueTemplate = value;
+            return *this;
+        }
+
         Builder& withSecondary(Component* c) {
             c->mainDevice = new DeviceConfig{ cmp->id };
             return *this;
@@ -255,10 +270,9 @@ namespace Ha {
     };
 
     struct TemperatureSensor : Sensor {
-        TemperatureSensor(const char* id) : Sensor("Temperature", id) {
+        TemperatureSensor(const char* id, const char* name = "Temperature") : Sensor(name, id) {
             deviceClass = "temperature";
             unitMeasure = "°C";
-            valueTemplate = "{{ value_json.sensor.temperature }}";
         }
     };