Add writeValueAtRange for index-range array writes

2 files changed, 80 insertions, 0 deletions

diff --git a/src/OpcUaMonitoredNode.cpp b/src/OpcUaMonitoredNode.cpp
index cd93730..922ad43 100644
--- a/src/OpcUaMonitoredNode.cpp
+++ b/src/OpcUaMonitoredNode.cpp
@@ -177,6 +177,7 @@ OpcUaMonitoredNode::teardownNode ()
   emit infoChanged ();
 
   m_valueType = QOpcUa::Types::Undefined;
+  m_pendingRangeWrite = false;
 
   if (m_writable)
     {
@@ -270,6 +271,9 @@ OpcUaMonitoredNode::handleAttributeUpdated (QOpcUa::NodeAttribute attr,
 void
 OpcUaMonitoredNode::handleValueUpdated (const QVariant &value)
 {
+  if (m_pendingRangeWrite)
+    return;
+
   m_value = value;
   emit valueChanged ();
 
@@ -306,6 +310,8 @@ OpcUaMonitoredNode::handleAttributeWritten (QOpcUa::NodeAttribute attr,
   if (attr != QOpcUa::NodeAttribute::Value)
     return;
 
+  m_pendingRangeWrite = false;
+
   bool ok = (statusCode == QOpcUa::Good);
   emit writeCompleted (ok, ok ? QStringLiteral ("Write successful")
                               : QOpcUa::statusToString (statusCode));
@@ -511,3 +517,64 @@ OpcUaMonitoredNode::writeValue (const QVariant &value)
     emit writeCompleted (false,
                          QStringLiteral ("Write request failed to dispatch"));
 }
+
+void
+OpcUaMonitoredNode::writeValueAtRange (const QVariant &value,
+                                       const QString &indexRange)
+{
+  if (!m_node)
+    {
+      emit writeCompleted (false, QStringLiteral ("Node not connected"));
+      return;
+    }
+  if (!m_writable)
+    {
+      emit writeCompleted (false, QStringLiteral ("Node is read-only"));
+      return;
+    }
+  if (m_valueType == QOpcUa::Types::Undefined)
+    {
+      emit writeCompleted (false,
+                           QStringLiteral ("Data type not yet resolved"));
+      return;
+    }
+  if (indexRange.isEmpty ())
+    {
+      emit writeCompleted (false, QStringLiteral ("Index range is empty"));
+      return;
+    }
+
+  QVariant toWrite = value;
+
+  // If the input is a comma-separated string, split into a list so
+  // coerceValue can handle each element (e.g. "10, 20" for range "0:1").
+  if (value.metaType ().id () == QMetaType::QString
+      && value.toString ().contains (QLatin1Char (',')))
+    {
+      QStringList parts
+          = value.toString ().split (QLatin1Char (','), Qt::SkipEmptyParts);
+      QVariantList list;
+      list.reserve (parts.size ());
+      for (const QString &part : parts)
+        list.append (QVariant (part.trimmed ()));
+      toWrite = QVariant::fromValue (list);
+    }
+
+  QVariant coerced = coerceValue (toWrite);
+  if (!coerced.isValid ())
+    {
+      emit writeCompleted (
+          false, QStringLiteral ("Cannot convert value to node data type"));
+      return;
+    }
+
+  m_pendingRangeWrite = true;
+
+  if (!m_node->writeAttributeRange (QOpcUa::NodeAttribute::Value, coerced,
+                                    indexRange, m_valueType))
+    {
+      m_pendingRangeWrite = false;
+      emit writeCompleted (
+          false, QStringLiteral ("Write range request failed to dispatch"));
+    }
+}
diff --git a/src/OpcUaMonitoredNode.h b/src/OpcUaMonitoredNode.h
index 2e86b2c..2ecffb7 100644
--- a/src/OpcUaMonitoredNode.h
+++ b/src/OpcUaMonitoredNode.h
@@ -88,6 +88,18 @@ public:
    */
   Q_INVOKABLE void writeValue (const QVariant &value);
 
+  /**
+   * @brief Write a value to a specific index range of an array node.
+   *
+   * @a indexRange uses OPC UA syntax: "0" for first element,
+   * "0:3" for elements 0–3, "0,1" for 2D indexing.
+   * For multi-element writes, @a value can be a comma-separated
+   * string or a QVariantList.
+   * Result is reported asynchronously via writeCompleted().
+   */
+  Q_INVOKABLE void writeValueAtRange (const QVariant &value,
+                                      const QString &indexRange);
+
   void classBegin () override;
   void componentComplete () override;
 
@@ -129,6 +141,7 @@ private:
   bool m_writable = false;
   QVariant m_value;
   OpcUaNodeInfo m_info;
+  bool m_pendingRangeWrite = false;
 };
 
 #endif // OPCUAMONITOREDNODE_H