UnlockConnector refactoring (#1006)

Refactored unlock_connector_callback for OCPP1.6:
* Callback must now return UnlockStatus instead of bool, because bool could not transmit enough information
* Within the UnlockConnector handler, stop_transaction_callback . This callback shall be responsible for this
---------

Signed-off-by: Piet Gömpel <pietgoempel@gmail.com>

Author: Pietfried

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.14)
 
 project(ocpp
-    VERSION 0.24.0
+    VERSION 0.24.1
     DESCRIPTION "A C++ implementation of the Open Charge Point Protocol"
     LANGUAGES CXX
 )

include/ocpp/v16/charge_point.hpp

@@ -428,13 +428,14 @@ class ChargePoint {
     /// \param callback
     void register_cancel_reservation_callback(const std::function<bool(int32_t reservation_id)>& callback);
 
-    /// \brief registers a \p callback function that can be used to unlock the connector. The unlock_connector_callback
-    /// is called:
+    /// \brief registers a \p callback function that can be used to unlock the connector. In case a transaction is
+    // active at the specified connector, the \p callback shall stop the transaction before unlocking the connector. The
+    // unlock_connector_callback is called:
     /// - when receiving a UnlockConnector.req and
     /// - when a transaction has on_transaction_stopped is called and the configuration key
     /// UnlockConnectorOnEVSideDisconnect is true
     /// \param callback
-    void register_unlock_connector_callback(const std::function<bool(int32_t connector)>& callback);
+    void register_unlock_connector_callback(const std::function<UnlockStatus(int32_t connector)>& callback);
 
     /// \brief registers a \p callback function that can be used to trigger an upload of diagnostics. This callback
     /// should trigger a process of a diagnostics upload using the given parameters of the request. This process should

include/ocpp/v16/charge_point_impl.hpp

@@ -156,7 +156,7 @@ class ChargePointImpl : ocpp::ChargingStationBase {
     std::function<void(const std::string& id_token, std::vector<int32_t> referenced_connectors, bool prevalidated)>
         provide_token_callback;
     std::function<bool(int32_t connector, Reason reason)> stop_transaction_callback;
-    std::function<bool(int32_t connector)> unlock_connector_callback;
+    std::function<UnlockStatus(int32_t connector)> unlock_connector_callback;
     std::function<bool(int32_t connector, int32_t max_current)> set_max_current_callback;
     std::function<bool(const ResetType& reset_type)> is_reset_allowed_callback;
     std::function<void(const ResetType& reset_type)> reset_callback;
@@ -732,13 +732,14 @@ class ChargePointImpl : ocpp::ChargingStationBase {
     /// \param callback
     void register_cancel_reservation_callback(const std::function<bool(int32_t reservation_id)>& callback);
 
-    /// \brief registers a \p callback function that can be used to unlock the connector. The unlock_connector_callback
-    /// is called:
+    /// \brief registers a \p callback function that can be used to unlock the connector. In case a transaction is
+    // active at the specified connector, the \p callback shall stop the transaction before unlocking the connector. The
+    // unlock_connector_callback is called:
     /// - when receiving a UnlockConnector.req and
     /// - when a transaction has on_transaction_stopped is called and the configuration key
     /// UnlockConnectorOnEVSideDisconnect is true
     /// \param callback
-    void register_unlock_connector_callback(const std::function<bool(int32_t connector)>& callback);
+    void register_unlock_connector_callback(const std::function<UnlockStatus(int32_t connector)>& callback);
 
     /// \brief registers a \p callback function that can be used to trigger an upload of diagnostics. This callback
     /// should trigger a process of a diagnostics upload using the given parameters of the request. This process should

lib/ocpp/v16/charge_point.cpp

@@ -230,7 +230,7 @@ void ChargePoint::register_cancel_reservation_callback(const std::function<bool(
     this->charge_point->register_cancel_reservation_callback(callback);
 }
 
-void ChargePoint::register_unlock_connector_callback(const std::function<bool(int32_t connector)>& callback) {
+void ChargePoint::register_unlock_connector_callback(const std::function<UnlockStatus(int32_t connector)>& callback) {
     this->charge_point->register_unlock_connector_callback(callback);
 }
 

lib/ocpp/v16/charge_point_impl.cpp

@@ -2306,19 +2306,9 @@ void ChargePointImpl::handleUnlockConnectorRequest(ocpp::Call<UnlockConnectorReq
     if (connector <= 0 or connector > this->configuration->getNumberOfConnectors()) {
         response.status = UnlockStatus::NotSupported;
     } else {
-        // this message is not intended to remotely stop a transaction, but if a transaction is still ongoing it is
-        // advised to stop it first
-        if (this->transaction_handler->transaction_active(connector)) {
-            EVLOG_info << "Received unlock connector request with active session for this connector.";
-            this->stop_transaction_callback(connector, Reason::UnlockCommand);
-        }
 
         if (this->unlock_connector_callback != nullptr) {
-            if (this->unlock_connector_callback(call.msg.connectorId)) {
-                response.status = UnlockStatus::Unlocked;
-            } else {
-                response.status = UnlockStatus::UnlockFailed;
-            }
+            response.status = this->unlock_connector_callback(call.msg.connectorId);
         } else {
             response.status = UnlockStatus::NotSupported;
         }
@@ -4495,7 +4485,8 @@ void ChargePointImpl::register_cancel_reservation_callback(const std::function<b
     this->cancel_reservation_callback = callback;
 }
 
-void ChargePointImpl::register_unlock_connector_callback(const std::function<bool(int32_t connector)>& callback) {
+void ChargePointImpl::register_unlock_connector_callback(
+    const std::function<UnlockStatus(int32_t connector)>& callback) {
     this->unlock_connector_callback = callback;
 }
 

src/charge_point.cpp

@@ -195,7 +195,7 @@ int main(int argc, char* argv[]) {
     charge_point->register_unlock_connector_callback([](int32_t connector) {
         std::cout << "Callback: "
                   << "Unlock connector#" << connector;
-        return true;
+        return ocpp::v16::UnlockStatus::Unlocked;
     });
 
     charge_point->register_upload_diagnostics_callback([](const ocpp::v16::GetDiagnosticsRequest& request) {