Use buildExpression command

Author: jgeudens

adapters/json-rpc-spec.md

@@ -292,7 +292,7 @@ Returns the schema for register expressions — what fields make up a register a
       "objectType": {
         "type": "string",
         "title": "Object type",
-        "enum": ["coil", "discrete-input", "input-register", "holding-register"],
+        "enum": ["coil", "discrete input", "input register", "holding register"],
         "x-enumLabels": ["Coil", "Discrete Input", "Input Register", "Holding Register"]
       },
       "address": {
@@ -341,12 +341,12 @@ Parses a register expression into structured fields and returns a human-readable
 {
   "valid": true,
   "fields": {
-    "objectType": "holding-register",
+    "objectType": "holding register",
     "address": 0,
     "deviceId": 1,
     "dataType": "16b"
   },
-  "description": "Holding register 0, device 1, unsigned 16-bit"
+  "description": "holding register, 0, unsigned 16-bit, device id 1"
 }
 ```
 
@@ -404,6 +404,13 @@ Validates a single register expression string without starting polling. Used for
 
 ---
 
+### `adapter.buildExpression`
+
+Constructs a register expression string from its component parts. The core calls this after the user fills in the register address form and selects a data type and device, so expression syntax stays entirely within the adapter.
+
+**Params:**
+---
+
 ### `adapter.getStatus`
 
 Returns the current poll activity state.

src/ProtocolAdapter/adapterclient.cpp

@@ -120,6 +120,33 @@ void AdapterClient::validateRegister(const QString& expression)
     _pProcess->sendRequest("adapter.validateRegister", params);
 }
 
+/*!
+ * \brief Send an adapter.buildExpression request to construct a register expression string.
+ * \param addressFields Address field values as returned by the register schema form.
+ * \param dataType      Data type identifier; omitted from params when empty.
+ * \param deviceId      Device identifier; omitted from params when zero.
+ */
+void AdapterClient::buildExpression(const QJsonObject& addressFields, const QString& dataType, deviceId_t deviceId)
+{
+    if (_state != State::AWAITING_CONFIG && _state != State::ACTIVE)
+    {
+        qCWarning(scopeComm) << "AdapterClient: buildExpression called in unexpected state" << static_cast<int>(_state);
+        return;
+    }
+
+    QJsonObject params;
+    params["fields"] = addressFields;
+    if (!dataType.isEmpty())
+    {
+        params["dataType"] = dataType;
+    }
+    if (deviceId != 0)
+    {
+        params["deviceId"] = static_cast<qint64>(deviceId);
+    }
+    _pProcess->sendRequest("adapter.buildExpression", params);
+}
+
 void AdapterClient::stopSession()
 {
     if (_state == State::IDLE || _state == State::STOPPING)
@@ -310,6 +337,10 @@ void AdapterClient::handleLifecycleResponse(const QString& method, const QJsonOb
     {
         emit validateRegisterResult(result["valid"].toBool(), result["error"].toString());
     }
+    else if (method == "adapter.buildExpression" && (_state == State::AWAITING_CONFIG || _state == State::ACTIVE))
+    {
+        emit buildExpressionResult(result["expression"].toString());
+    }
     else
     {
         qCWarning(scopeComm) << "AdapterClient: unexpected response for" << method << "in state"

src/ProtocolAdapter/adapterclient.h

@@ -2,6 +2,7 @@
 #define ADAPTERCLIENT_H
 
 #include "ProtocolAdapter/adapterprocess.h"
+#include "models/device.h"
 #include "util/result.h"
 
 #include <QJsonObject>
@@ -106,6 +107,18 @@ class AdapterClient : public QObject
      */
     void validateRegister(const QString& expression);
 
+    /*!
+     * \brief Send an adapter.buildExpression request to construct a register expression string.
+     *
+     * Can be called in AWAITING_CONFIG or ACTIVE state.
+     * Emits buildExpressionResult() when the adapter responds.
+     *
+     * \param addressFields Address field values as returned by the register schema form (e.g. objectType, address).
+     * \param dataType      Data type identifier (e.g. "16b"). Omitted from params when empty; adapter uses its default.
+     * \param deviceId      Device identifier. Omitted from params when zero; adapter uses its default.
+     */
+    void buildExpression(const QJsonObject& addressFields, const QString& dataType, deviceId_t deviceId);
+
 signals:
     /*!
      * \brief Emitted when the adapter has been initialized, described, configured, and started.
@@ -171,6 +184,12 @@ class AdapterClient : public QObject
      */
     void validateRegisterResult(bool valid, QString error);
 
+    /*!
+     * \brief Emitted when an adapter.buildExpression response has been received.
+     * \param expression The constructed register expression string (e.g. \c ${h0:f32b}).
+     */
+    void buildExpressionResult(QString expression);
+
 protected:
     enum class State
     {

src/communication/modbuspoll.cpp

@@ -24,6 +24,7 @@ ModbusPoll::ModbusPoll(SettingsModel* pSettingsModel, QObject* parent) : QObject
     connect(_pAdapterClient, &AdapterClient::readDataResult, this, &ModbusPoll::onReadDataResult);
     connect(_pAdapterClient, &AdapterClient::describeResult, this, &ModbusPoll::onDescribeResult);
     connect(_pAdapterClient, &AdapterClient::registerSchemaResult, this, &ModbusPoll::onRegisterSchemaResult);
+    connect(_pAdapterClient, &AdapterClient::buildExpressionResult, this, &ModbusPoll::buildExpressionResult);
     connect(_pAdapterClient, &AdapterClient::sessionError, this, [this](QString message) {
         qCWarning(scopeComm) << "AdapterClient error:" << message;
         _bPollActive = false;
@@ -165,6 +166,17 @@ void ModbusPoll::onAdapterDiagnostic(const QString& level, const QString& messag
     }
 }
 
+/*!
+ * \brief Request the adapter to construct a register expression from its component parts.
+ * \param addressFields Address field values from the register schema form.
+ * \param dataType      Data type identifier; empty string uses the adapter default.
+ * \param deviceId      Device identifier; 0 uses the adapter default.
+ */
+void ModbusPoll::buildExpression(const QJsonObject& addressFields, const QString& dataType, deviceId_t deviceId)
+{
+    _pAdapterClient->buildExpression(addressFields, dataType, deviceId);
+}
+
 QStringList ModbusPoll::buildRegisterExpressions(const QList<DataPoint>& registerList)
 {
     QStringList expressions;

src/communication/modbuspoll.h

@@ -29,9 +29,26 @@ class ModbusPoll : public QObject
 
     void onAdapterDiagnostic(const QString& level, const QString& message);
 
+    /*!
+     * \brief Request the adapter to construct a register expression string from its component parts.
+     *
+     * Delegates to AdapterClient::buildExpression(). Emits buildExpressionResult() on response.
+     *
+     * \param addressFields Address field values as returned by the register schema form.
+     * \param dataType      Data type identifier (e.g. "16b"). Pass empty string to use the adapter default.
+     * \param deviceId      Device identifier. Pass 0 to use the adapter default.
+     */
+    virtual void buildExpression(const QJsonObject& addressFields, const QString& dataType, deviceId_t deviceId);
+
 signals:
     void registerDataReady(ResultDoubleList registers);
 
+    /*!
+     * \brief Emitted when an adapter.buildExpression response has been received.
+     * \param expression The constructed register expression string (e.g. \c ${h0:f32b}).
+     */
+    void buildExpressionResult(QString expression);
+
 private slots:
     void triggerRegisterRead();
     void onReadDataResult(ResultDoubleList results);

src/dialogs/addregisterwidget.cpp

@@ -1,11 +1,11 @@
 #include "addregisterwidget.h"
 #include "ui_addregisterwidget.h"
 
+#include "communication/modbuspoll.h"
 #include "customwidgets/schemaformwidget.h"
 #include "models/adapterdata.h"
 #include "models/device.h"
 #include "models/settingsmodel.h"
-#include "util/expressiongenerator.h"
 
 #include <QJsonArray>
 #include <QVBoxLayout>
@@ -14,13 +14,18 @@
  * \brief Constructs the widget and populates it from the adapter's register schema.
  * \param pSettingsModel Pointer to the application settings model.
  * \param adapterId      Identifier of the adapter whose register schema to use.
+ * \param pModbusPoll    Pointer to the Modbus poll instance used to build expression strings.
  * \param parent         Optional parent widget.
  */
-AddRegisterWidget::AddRegisterWidget(SettingsModel* pSettingsModel, const QString& adapterId, QWidget* parent)
+AddRegisterWidget::AddRegisterWidget(SettingsModel* pSettingsModel,
+                                     const QString& adapterId,
+                                     ModbusPoll* pModbusPoll,
+                                     QWidget* parent)
     : QWidget(parent),
       _pUi(new Ui::AddRegisterWidget),
       _pAddressForm(new SchemaFormWidget(this)),
-      _pSettingsModel(pSettingsModel)
+      _pSettingsModel(pSettingsModel),
+      _pModbusPoll(pModbusPoll)
 {
     _pUi->setupUi(this);
 
@@ -72,6 +77,7 @@ AddRegisterWidget::AddRegisterWidget(SettingsModel* pSettingsModel, const QStrin
     }
 
     connect(_pUi->btnAdd, &QPushButton::clicked, this, &AddRegisterWidget::handleResultAccept);
+    connect(_pModbusPoll, &ModbusPoll::buildExpressionResult, this, &AddRegisterWidget::onBuildExpressionResult);
 
     _axisGroup.setExclusive(true);
     _axisGroup.addButton(_pUi->radioPrimary);
@@ -87,28 +93,38 @@ AddRegisterWidget::~AddRegisterWidget()
 
 void AddRegisterWidget::handleResultAccept()
 {
-    const QString expression = generateExpression();
-    if (expression.isEmpty())
+    if (_pUi->cmbDevice->count() == 0)
     {
         return;
     }
 
-    GraphData graphData;
+    collectPendingGraphData();
 
-    graphData.setLabel(_pUi->lineName->text());
+    const QJsonObject addressValues = _pAddressForm->values();
+    const QString typeId = _pUi->cmbType->currentData().toString();
 
-    if (_pUi->radioSecondary->isChecked())
+    deviceId_t deviceId = Device::cFirstDeviceId;
+    const QVariant devData = _pUi->cmbDevice->currentData();
+    if (devData.canConvert<deviceId_t>())
     {
-        graphData.setValueAxis(GraphData::VALUE_AXIS_SECONDARY);
+        deviceId = devData.value<deviceId_t>();
     }
-    else
+
+    _pUi->btnAdd->setEnabled(false);
+    _pModbusPoll->buildExpression(addressValues, typeId, deviceId);
+}
+
+void AddRegisterWidget::onBuildExpressionResult(const QString& expression)
+{
+    _pUi->btnAdd->setEnabled(true);
+
+    if (expression.isEmpty())
     {
-        graphData.setValueAxis(GraphData::VALUE_AXIS_PRIMARY);
+        return;
     }
 
-    graphData.setExpression(expression);
-
-    emit graphDataConfigured(graphData);
+    _pendingGraphData.setExpression(expression);
+    emit graphDataConfigured(_pendingGraphData);
 
     resetFields();
 }
@@ -122,29 +138,23 @@ void AddRegisterWidget::resetFields()
     _pAddressForm->setSchema(_addressSchema, QJsonObject());
 }
 
-QString AddRegisterWidget::generateExpression()
+/*!
+ * \brief Captures the current non-expression fields into \a _pendingGraphData.
+ *
+ * Called just before the async adapter.buildExpression request is sent, so that
+ * the label and value axis are snapshotted at click time.
+ */
+void AddRegisterWidget::collectPendingGraphData()
 {
-    if (_pUi->cmbDevice->count() == 0)
-    {
-        return QString();
-    }
+    _pendingGraphData = GraphData();
+    _pendingGraphData.setLabel(_pUi->lineName->text());
 
-    const QJsonObject addressValues = _pAddressForm->values();
-    if (!addressValues.contains("objectType") || !addressValues.contains("address"))
+    if (_pUi->radioSecondary->isChecked())
     {
-        return QString();
+        _pendingGraphData.setValueAxis(GraphData::VALUE_AXIS_SECONDARY);
     }
-
-    const QString objectType = addressValues["objectType"].toString();
-    const int address = addressValues["address"].toInt();
-    const QString typeId = _pUi->cmbType->currentData().toString();
-
-    deviceId_t deviceId = Device::cFirstDeviceId;
-    const QVariant devData = _pUi->cmbDevice->currentData();
-    if (devData.canConvert<deviceId_t>())
+    else
     {
-        deviceId = devData.value<deviceId_t>();
+        _pendingGraphData.setValueAxis(GraphData::VALUE_AXIS_PRIMARY);
     }
-
-    return ExpressionGenerator::constructRegisterString(objectType, address, typeId, deviceId);
 }

src/dialogs/addregisterwidget.h

@@ -1,12 +1,14 @@
 #ifndef ADDREGISTERWIDGET_H
 #define ADDREGISTERWIDGET_H
 
+#include "models/device.h"
 #include "models/graphdata.h"
 
 #include <QButtonGroup>
 #include <QJsonObject>
 #include <QWidget>
 
+class ModbusPoll;
 class SchemaFormWidget;
 class SettingsModel;
 
@@ -21,27 +23,35 @@ class AddRegisterWidget : public QWidget
     friend class TestAddRegisterWidget;
 
 public:
-    explicit AddRegisterWidget(SettingsModel* pSettingsModel, const QString& adapterId, QWidget* parent = nullptr);
+    explicit AddRegisterWidget(SettingsModel* pSettingsModel,
+                               const QString& adapterId,
+                               ModbusPoll* pModbusPoll,
+                               QWidget* parent = nullptr);
     ~AddRegisterWidget();
 
 signals:
     void graphDataConfigured(GraphData graphData);
 
 private slots:
     void handleResultAccept();
+    void onBuildExpressionResult(const QString& expression);
 
 private:
     void resetFields();
-    QString generateExpression();
+    void collectPendingGraphData();
 
     Ui::AddRegisterWidget* _pUi;
     SchemaFormWidget* _pAddressForm;
     QJsonObject _addressSchema;
     int _defaultTypeIndex{ 0 };
 
     SettingsModel* _pSettingsModel;
+    ModbusPoll* _pModbusPoll;
 
     QButtonGroup _axisGroup;
+
+    /* Temporary storage while waiting for buildExpression response */
+    GraphData _pendingGraphData;
 };
 
 #endif // ADDREGISTERWIDGET_H

src/dialogs/mainwindow.cpp

@@ -397,7 +397,7 @@ void MainWindow::showRegisterDialog()
         _pGuiModel->setGuiState(GuiState::INIT);
     }
 
-    RegisterDialog registerDialog(_pGraphDataModel, _pSettingsModel, this);
+    RegisterDialog registerDialog(_pGraphDataModel, _pSettingsModel, _pModbusPoll, this);
     registerDialog.exec();
 }