From 1305e9418227ea3badac2710b39a17d3c96a3bca Mon Sep 17 00:00:00 2001
From: Randy Armstrong <randy@sparhawksoftware.com>
Date: Fri, 5 Feb 2021 18:35:53 +0900
Subject: [PATCH 1/3] Merge model compiler fixes with latest code.

---
 .../Stack/State/ModelCompilerExtension.cs     | 69 +++++++++++++
 Stack/Opc.Ua.Core/Stack/State/NodeState.cs    |  2 +-
 .../Stack/State/NodeStateCollection.cs        |  2 +-
 .../Opc.Ua.Core/Types/Encoders/JsonEncoder.cs | 99 ++++++++++---------
 .../Opc.Ua.Core/Types/Encoders/XmlEncoder.cs  | 29 +++++-
 5 files changed, 148 insertions(+), 53 deletions(-)
 create mode 100644 Stack/Opc.Ua.Core/Stack/State/ModelCompilerExtension.cs

diff --git a/Stack/Opc.Ua.Core/Stack/State/ModelCompilerExtension.cs b/Stack/Opc.Ua.Core/Stack/State/ModelCompilerExtension.cs
new file mode 100644
index 0000000000..b5eaa62203
--- /dev/null
+++ b/Stack/Opc.Ua.Core/Stack/State/ModelCompilerExtension.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.IO;
+using System.Threading.Tasks;
+
+namespace Opc.Ua
+{
+    public partial class NodeState
+    {
+        /// <summary>
+        /// The specification that defines the node.
+        /// </summary>
+        public string Specification { get; set; }
+
+        /// <summary>
+        /// The documentation for the node that is saved in the NodeSet.
+        /// </summary>
+        public string NodeSetDocumentation { get; set; }
+    }
+
+    public partial class StructureDefinition
+    {
+        /// <summary>
+        /// The first non-inherited field in the structure definition.
+        /// </summary>
+        public int FirstExplicitFieldIndex { get; set; }
+    }
+
+    public partial class NodeStateCollection
+    {
+        /// <summary>
+        /// Writes the collection to a stream using the Opc.Ua.Schema.UANodeSet schema.
+        /// </summary>
+        public void SaveAsNodeSet2(
+            ISystemContext context,
+            Stream ostrm,
+            Export.ModelTableEntry model,
+            DateTime lastModified,
+            bool outputRedundantNames)
+        {
+            Opc.Ua.Export.UANodeSet nodeSet = new Opc.Ua.Export.UANodeSet();
+
+            if (lastModified != DateTime.MinValue)
+            {
+                nodeSet.LastModified = lastModified;
+                nodeSet.LastModifiedSpecified = true;
+            }
+
+            if (model != null)
+            {
+                nodeSet.Models = new Export.ModelTableEntry[] { model };
+            }
+
+            for (int ii = 0; ii < s_AliasesToUse.Length; ii++)
+            {
+                nodeSet.AddAlias(context, s_AliasesToUse[ii].Alias, s_AliasesToUse[ii].NodeId);
+            }
+
+            for (int ii = 0; ii < this.Count; ii++)
+            {
+                nodeSet.Export(context, this[ii], outputRedundantNames);
+            }
+
+            nodeSet.Write(ostrm);
+        }
+    }
+}
diff --git a/Stack/Opc.Ua.Core/Stack/State/NodeState.cs b/Stack/Opc.Ua.Core/Stack/State/NodeState.cs
index 8d0e67b57f..29fb50f64a 100644
--- a/Stack/Opc.Ua.Core/Stack/State/NodeState.cs
+++ b/Stack/Opc.Ua.Core/Stack/State/NodeState.cs
@@ -23,7 +23,7 @@ namespace Opc.Ua
     /// <summary>
     /// The base class for custom nodes.
     /// </summary>
-    public abstract class NodeState : IDisposable, IFormattable
+    public abstract partial class NodeState : IDisposable, IFormattable
     {
         #region Constructors
         /// <summary>
diff --git a/Stack/Opc.Ua.Core/Stack/State/NodeStateCollection.cs b/Stack/Opc.Ua.Core/Stack/State/NodeStateCollection.cs
index be6a3d6ead..266f7c2eb7 100644
--- a/Stack/Opc.Ua.Core/Stack/State/NodeStateCollection.cs
+++ b/Stack/Opc.Ua.Core/Stack/State/NodeStateCollection.cs
@@ -23,7 +23,7 @@ namespace Opc.Ua
     /// <summary>
     /// Stores a collection of nodes.
     /// </summary>
-    public class NodeStateCollection : List<NodeState>
+    public partial class NodeStateCollection : List<NodeState>
     {
         #region Constructors
         /// <summary>
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
index 9ef1853411..4e5886851e 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
@@ -228,14 +228,14 @@ namespace Opc.Ua
         {
             if (!m_dontWriteClosing)
             {
-                if (m_topLevelIsArray)
-                {
-                    m_writer.Write("]");
-                }
-                else
-                {
-                    m_writer.Write("}");
-                }
+            if (m_topLevelIsArray)
+            {
+                m_writer.Write("]");
+            }
+            else
+            {
+                m_writer.Write("}");
+            }
             }
 
             m_writer.Flush();
@@ -1296,6 +1296,7 @@ namespace Opc.Ua
                     m_context.MaxEncodingNestingLevels);
             }
 
+
             if (value == null)
             {
                 WriteSimpleField(fieldName, null, false);
@@ -1376,7 +1377,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteBooleanArray(string fieldName, IList<bool> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1403,7 +1404,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteSByteArray(string fieldName, IList<sbyte> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1430,7 +1431,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteArray(string fieldName, IList<byte> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1457,7 +1458,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt16Array(string fieldName, IList<short> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1484,7 +1485,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt16Array(string fieldName, IList<ushort> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1511,7 +1512,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt32Array(string fieldName, IList<int> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1538,7 +1539,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt32Array(string fieldName, IList<uint> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1565,7 +1566,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt64Array(string fieldName, IList<long> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1592,7 +1593,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt64Array(string fieldName, IList<ulong> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1619,7 +1620,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteFloatArray(string fieldName, IList<float> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1646,7 +1647,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDoubleArray(string fieldName, IList<double> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1673,7 +1674,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStringArray(string fieldName, IList<string> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1700,7 +1701,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDateTimeArray(string fieldName, IList<DateTime> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1734,7 +1735,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Uuid> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1761,7 +1762,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Guid> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1788,7 +1789,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteStringArray(string fieldName, IList<byte[]> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1815,7 +1816,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteXmlElementArray(string fieldName, IList<XmlElement> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1842,7 +1843,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteNodeIdArray(string fieldName, IList<NodeId> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1869,7 +1870,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExpandedNodeIdArray(string fieldName, IList<ExpandedNodeId> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1896,7 +1897,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStatusCodeArray(string fieldName, IList<StatusCode> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1931,7 +1932,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDiagnosticInfoArray(string fieldName, IList<DiagnosticInfo> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1958,7 +1959,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteQualifiedNameArray(string fieldName, IList<QualifiedName> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1985,7 +1986,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteLocalizedTextArray(string fieldName, IList<LocalizedText> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2012,7 +2013,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteVariantArray(string fieldName, IList<Variant> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2045,7 +2046,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDataValueArray(string fieldName, IList<DataValue> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2072,7 +2073,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExtensionObjectArray(string fieldName, IList<ExtensionObject> values)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2099,7 +2100,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteEncodeableArray(string fieldName, IList<IEncodeable> values, System.Type systemType)
         {
-            if (values == null)
+            if (values == null || values.Count == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2136,18 +2137,18 @@ namespace Opc.Ua
             {
                 PushArray(fieldName);
 
-                // check the length.
-                if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
-                {
-                    throw new ServiceResultException(StatusCodes.BadEncodingLimitsExceeded);
-                }
+	            // check the length.
+	            if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
+	            {
+	                throw new ServiceResultException(StatusCodes.BadEncodingLimitsExceeded);
+	            }
 
-                for (int ii = 0; ii < values.Count; ii++)
-                {
-                    WriteEncodeable(null, values[ii], systemType);
-                }
+	            for (int ii = 0; ii < values.Count; ii++)
+	            {
+	                WriteEncodeable(null, values[ii], systemType);
+	            }
 
-                PopArray();
+	            PopArray();
             }
         }
 
@@ -2156,7 +2157,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteEnumeratedArray(string fieldName, Array values, System.Type systemType)
         {
-            if (values == null)
+            if (values == null || values.Length == 0)
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2382,6 +2383,12 @@ namespace Opc.Ua
         /// </summary>
         public void WriteObjectArray(string fieldName, IList<object> values)
         {
+            if (values == null || values.Count == 0)
+            {
+                WriteSimpleField(fieldName, null, false);
+                return;
+            }
+
             PushArray(fieldName);
 
             if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
index a4a2a8506b..ec9f8566e3 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
@@ -39,6 +39,8 @@ namespace Opc.Ua
             XmlWriterSettings settings = new XmlWriterSettings();
             settings.CheckCharacters = false;
             settings.ConformanceLevel = ConformanceLevel.Auto;
+            settings.NamespaceHandling = NamespaceHandling.OmitDuplicates;
+            settings.NewLineHandling = NewLineHandling.Replace;
 
             m_writer = XmlWriter.Create(m_destination, settings);
         }
@@ -443,7 +445,11 @@ namespace Opc.Ua
                     throw new ServiceResultException(StatusCodes.BadEncodingLimitsExceeded);
                 }
 
-                m_writer.WriteString(value);
+                if (!String.IsNullOrWhiteSpace(value))
+                {
+                    m_writer.WriteString(value);
+                }
+
                 EndField(fieldName);
             }
         }
@@ -504,7 +510,7 @@ namespace Opc.Ua
                     throw new ServiceResultException(StatusCodes.BadEncodingLimitsExceeded);
                 }
 
-                m_writer.WriteValue(Convert.ToBase64String(value));
+                m_writer.WriteValue(Convert.ToBase64String(value, Base64FormattingOptions.InsertLineBreaks));
                 EndField(fieldName);
             }
         }
@@ -684,8 +690,15 @@ namespace Opc.Ua
 
                 if (value != null)
                 {
-                    WriteString("Locale", value.Locale);
-                    WriteString("Text", value.Text);
+                    if (!String.IsNullOrEmpty(value.Locale))
+                    {
+                        WriteString("Locale", value.Locale);
+                    }
+
+                    if (!String.IsNullOrEmpty(value.Text))
+                    {
+                        WriteString("Text", value.Text);
+                    }
                 }
 
                 PopNamespace();
@@ -1817,6 +1830,7 @@ namespace Opc.Ua
                                     ints[ii] = (int)(object)enums[ii];
                                 }
                             }
+
                             WriteInt32Array("ListOfInt32", ints);
                             return;
                         }
@@ -1882,7 +1896,7 @@ namespace Opc.Ua
             if (bytes != null)
             {
                 m_writer.WriteStartElement("ByteString", Namespaces.OpcUaXsd);
-                m_writer.WriteString(Convert.ToBase64String(bytes));
+                m_writer.WriteString(Convert.ToBase64String(bytes, Base64FormattingOptions.InsertLineBreaks));
                 m_writer.WriteEndElement();
                 return;
             }
@@ -1977,6 +1991,11 @@ namespace Opc.Ua
             // specifying a null field name means the start/end tags should not be written.
             if (!String.IsNullOrEmpty(fieldName))
             {
+                if (isNillable && isDefault)
+                {
+                    return false;
+                }
+
                 m_writer.WriteStartElement(fieldName, m_namespaces.Peek());
 
                 if (isDefault)

From c22ecec8f5e7361742a9d05db44ce982b6fc29f1 Mon Sep 17 00:00:00 2001
From: Randy Armstrong <randy@sparhawksoftware.com>
Date: Fri, 5 Feb 2021 19:14:10 +0900
Subject: [PATCH 2/3] Fix XmlEncoder.

---
 .../Opc.Ua.Core/Types/Encoders/XmlEncoder.cs  | 64 +++++++++----------
 1 file changed, 32 insertions(+), 32 deletions(-)

diff --git a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
index ec9f8566e3..8693a1edf6 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
@@ -897,7 +897,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteBooleanArray(string fieldName, IList<bool> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -926,7 +926,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteSByteArray(string fieldName, IList<sbyte> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -955,7 +955,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteArray(string fieldName, IList<byte> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -984,7 +984,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt16Array(string fieldName, IList<short> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1013,7 +1013,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt16Array(string fieldName, IList<ushort> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1042,7 +1042,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt32Array(string fieldName, IList<int> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1071,7 +1071,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt32Array(string fieldName, IList<uint> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1100,7 +1100,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt64Array(string fieldName, IList<long> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1129,7 +1129,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt64Array(string fieldName, IList<ulong> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1158,7 +1158,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteFloatArray(string fieldName, IList<float> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1187,7 +1187,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDoubleArray(string fieldName, IList<double> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1216,7 +1216,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStringArray(string fieldName, IList<string> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1245,7 +1245,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDateTimeArray(string fieldName, IList<DateTime> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1274,7 +1274,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Uuid> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1303,7 +1303,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Guid> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1332,7 +1332,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteStringArray(string fieldName, IList<byte[]> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1361,7 +1361,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteXmlElementArray(string fieldName, IList<XmlElement> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1390,7 +1390,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteNodeIdArray(string fieldName, IList<NodeId> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1419,7 +1419,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExpandedNodeIdArray(string fieldName, IList<ExpandedNodeId> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1448,7 +1448,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStatusCodeArray(string fieldName, IList<StatusCode> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1477,7 +1477,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDiagnosticInfoArray(string fieldName, IList<DiagnosticInfo> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1506,7 +1506,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteQualifiedNameArray(string fieldName, IList<QualifiedName> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1535,7 +1535,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteLocalizedTextArray(string fieldName, IList<LocalizedText> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1564,7 +1564,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteVariantArray(string fieldName, IList<Variant> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1593,7 +1593,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDataValueArray(string fieldName, IList<DataValue> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1622,7 +1622,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExtensionObjectArray(string fieldName, IList<ExtensionObject> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1651,7 +1651,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteEncodeableArray(string fieldName, IList<IEncodeable> values, System.Type systemType)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1698,7 +1698,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteEnumeratedArray(string fieldName, Array values, System.Type systemType)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Length)
@@ -1935,7 +1935,7 @@ namespace Opc.Ua
         /// </summary>
         private void WriteMatrix(string fieldName, Matrix value)
         {
-            if (BeginField(fieldName, value == null, true))
+            if (BeginField(fieldName, value == null, true, true))
             {
                 PushNamespace(Namespaces.OpcUaXsd);
 
@@ -1959,7 +1959,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteObjectArray(string fieldName, IList<object> values)
         {
-            if (BeginField(fieldName, values == null, true))
+            if (BeginField(fieldName, values == null, true, true))
             {
                 // check the length.
                 if (m_context.MaxArrayLength > 0 && m_context.MaxArrayLength < values.Count)
@@ -1986,12 +1986,12 @@ namespace Opc.Ua
         /// <summary>
         /// Writes the start element for a field.
         /// </summary>
-        private bool BeginField(string fieldName, bool isDefault, bool isNillable)
+        private bool BeginField(string fieldName, bool isDefault, bool isNillable, bool isArrayElement = false)
         {
             // specifying a null field name means the start/end tags should not be written.
             if (!String.IsNullOrEmpty(fieldName))
             {
-                if (isNillable && isDefault)
+                if (isNillable && isDefault && !isArrayElement)
                 {
                     return false;
                 }

From e016a9bb298fa60671ada928b85a604e90f2b99c Mon Sep 17 00:00:00 2001
From: Randy Armstrong <randy@sparhawksoftware.com>
Date: Fri, 5 Feb 2021 23:53:30 +0900
Subject: [PATCH 3/3] Fix unit tests errors.

---
 Stack/Opc.Ua.Core/Schema/UANodeSetHelpers.cs  |  17 +-
 .../Opc.Ua.Core/Types/Encoders/JsonEncoder.cs | 302 +++++++++---------
 .../Opc.Ua.Core/Types/Encoders/XmlDecoder.cs  |  11 +-
 .../Opc.Ua.Core/Types/Encoders/XmlEncoder.cs  |  27 +-
 .../Types/Schemas/SchemaValidator.cs          |   6 +-
 .../Types/Encoders/EncoderCommon.cs           |   7 +-
 6 files changed, 209 insertions(+), 161 deletions(-)

diff --git a/Stack/Opc.Ua.Core/Schema/UANodeSetHelpers.cs b/Stack/Opc.Ua.Core/Schema/UANodeSetHelpers.cs
index a7e19357a1..9d0573ce50 100644
--- a/Stack/Opc.Ua.Core/Schema/UANodeSetHelpers.cs
+++ b/Stack/Opc.Ua.Core/Schema/UANodeSetHelpers.cs
@@ -295,6 +295,7 @@ namespace Opc.Ua.Export
                 exportedNode.Description = new LocalizedText[0];
             }
 
+            exportedNode.Documentation = node.NodeSetDocumentation;
             exportedNode.Category = (node.Categories != null && node.Categories.Count > 0) ? new List<string>(node.Categories).ToArray() : null;
             exportedNode.ReleaseStatus = node.ReleaseStatus;
             exportedNode.WriteMask = (uint)node.WriteMask;
@@ -624,6 +625,7 @@ namespace Opc.Ua.Export
             }
 
             importedNode.Description = Import(node.Description);
+            importedNode.NodeSetDocumentation = node.Documentation;
             importedNode.Categories = (node.Category != null && node.Category.Length > 0) ? node.Category : null;
             importedNode.ReleaseStatus = node.ReleaseStatus;
             importedNode.WriteMask = (AttributeWriteMask)node.WriteMask;
@@ -909,8 +911,10 @@ namespace Opc.Ua.Export
                 {
                     List<Opc.Ua.Export.DataTypeField> fields = new List<DataTypeField>();
 
-                    foreach (StructureField field in structureDefinition.Fields)
+                    for (int ii = structureDefinition.FirstExplicitFieldIndex; ii < structureDefinition.Fields.Count; ii++)
                     {
+                        StructureField field = structureDefinition.Fields[ii];
+
                         Opc.Ua.Export.DataTypeField output = new Opc.Ua.Export.DataTypeField();
 
                         output.Name = field.Name;
@@ -948,7 +952,16 @@ namespace Opc.Ua.Export
                         Opc.Ua.Export.DataTypeField output = new Opc.Ua.Export.DataTypeField();
 
                         output.Name = field.Name;
-                        output.DisplayName = Export(new Opc.Ua.LocalizedText[] { field.Name });
+
+                        if (field.DisplayName != null && output.Name != field.DisplayName.Text)
+                        {
+                            output.DisplayName = Export(new Opc.Ua.LocalizedText[] { field.DisplayName });
+                        }
+                        else
+                        {
+                            output.DisplayName = new LocalizedText[0];
+                        }
+
                         output.Description = Export(new Opc.Ua.LocalizedText[] { field.Description });
                         output.ValueRank = ValueRanks.Scalar;
                         output.Value = (int)field.Value;
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
index 4e5886851e..03cc09ee48 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/JsonEncoder.cs
@@ -29,6 +29,7 @@ namespace Opc.Ua
         private StreamWriter m_writer;
         private Stack<string> m_namespaces;
         private bool m_commaRequired;
+        private bool m_inVariantWithEncoding;
         private ServiceMessageContext m_context;
         private ushort[] m_namespaceMappings;
         private ushort[] m_serverMappings;
@@ -1377,7 +1378,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteBooleanArray(string fieldName, IList<bool> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1404,7 +1405,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteSByteArray(string fieldName, IList<sbyte> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1431,7 +1432,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteArray(string fieldName, IList<byte> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1458,7 +1459,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt16Array(string fieldName, IList<short> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1485,7 +1486,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt16Array(string fieldName, IList<ushort> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1512,7 +1513,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt32Array(string fieldName, IList<int> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1539,7 +1540,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt32Array(string fieldName, IList<uint> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1566,7 +1567,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteInt64Array(string fieldName, IList<long> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1593,7 +1594,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteUInt64Array(string fieldName, IList<ulong> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1620,7 +1621,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteFloatArray(string fieldName, IList<float> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1647,7 +1648,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDoubleArray(string fieldName, IList<double> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1674,7 +1675,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStringArray(string fieldName, IList<string> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1701,7 +1702,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDateTimeArray(string fieldName, IList<DateTime> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1735,7 +1736,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Uuid> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1762,7 +1763,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteGuidArray(string fieldName, IList<Guid> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1789,7 +1790,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteStringArray(string fieldName, IList<byte[]> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1816,7 +1817,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteXmlElementArray(string fieldName, IList<XmlElement> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1843,7 +1844,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteNodeIdArray(string fieldName, IList<NodeId> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1870,7 +1871,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExpandedNodeIdArray(string fieldName, IList<ExpandedNodeId> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1897,7 +1898,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteStatusCodeArray(string fieldName, IList<StatusCode> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1932,7 +1933,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDiagnosticInfoArray(string fieldName, IList<DiagnosticInfo> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1959,7 +1960,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteQualifiedNameArray(string fieldName, IList<QualifiedName> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -1986,7 +1987,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteLocalizedTextArray(string fieldName, IList<LocalizedText> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2013,7 +2014,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteVariantArray(string fieldName, IList<Variant> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2046,7 +2047,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteDataValueArray(string fieldName, IList<DataValue> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2073,7 +2074,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteExtensionObjectArray(string fieldName, IList<ExtensionObject> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2100,7 +2101,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteEncodeableArray(string fieldName, IList<IEncodeable> values, System.Type systemType)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
@@ -2204,130 +2205,139 @@ namespace Opc.Ua
         /// </summary>
         public void WriteVariantContents(object value, TypeInfo typeInfo)
         {
-            // check for null.
-            if (value == null)
+            try
             {
-                return;
-            }
+                m_inVariantWithEncoding = UseReversibleEncoding;
 
-            m_commaRequired = false;
-
-            // write scalar.
-            if (typeInfo.ValueRank < 0)
-            {
-                switch (typeInfo.BuiltInType)
+                // check for null.
+                if (value == null)
                 {
-                    case BuiltInType.Boolean: { WriteBoolean(null, (bool)value); return; }
-                    case BuiltInType.SByte: { WriteSByte(null, (sbyte)value); return; }
-                    case BuiltInType.Byte: { WriteByte(null, (byte)value); return; }
-                    case BuiltInType.Int16: { WriteInt16(null, (short)value); return; }
-                    case BuiltInType.UInt16: { WriteUInt16(null, (ushort)value); return; }
-                    case BuiltInType.Int32: { WriteInt32(null, (int)value); return; }
-                    case BuiltInType.UInt32: { WriteUInt32(null, (uint)value); return; }
-                    case BuiltInType.Int64: { WriteInt64(null, (long)value); return; }
-                    case BuiltInType.UInt64: { WriteUInt64(null, (ulong)value); return; }
-                    case BuiltInType.Float: { WriteFloat(null, (float)value); return; }
-                    case BuiltInType.Double: { WriteDouble(null, (double)value); return; }
-                    case BuiltInType.String: { WriteString(null, (string)value); return; }
-                    case BuiltInType.DateTime: { WriteDateTime(null, (DateTime)value); return; }
-                    case BuiltInType.Guid: { WriteGuid(null, (Uuid)value); return; }
-                    case BuiltInType.ByteString: { WriteByteString(null, (byte[])value); return; }
-                    case BuiltInType.XmlElement: { WriteXmlElement(null, (XmlElement)value); return; }
-                    case BuiltInType.NodeId: { WriteNodeId(null, (NodeId)value); return; }
-                    case BuiltInType.ExpandedNodeId: { WriteExpandedNodeId(null, (ExpandedNodeId)value); return; }
-                    case BuiltInType.StatusCode: { WriteStatusCode(null, (StatusCode)value); return; }
-                    case BuiltInType.QualifiedName: { WriteQualifiedName(null, (QualifiedName)value); return; }
-                    case BuiltInType.LocalizedText: { WriteLocalizedText(null, (LocalizedText)value); return; }
-                    case BuiltInType.ExtensionObject: { WriteExtensionObject(null, (ExtensionObject)value); return; }
-                    case BuiltInType.DataValue: { WriteDataValue(null, (DataValue)value); return; }
-                    case BuiltInType.Enumeration: { WriteEnumerated(null, (Enum)value); return; }
-                }
-            }
-
-            // write array.
-            else if (typeInfo.ValueRank <= 1)
-            {
-                switch (typeInfo.BuiltInType)
-                {
-                    case BuiltInType.Boolean: { WriteBooleanArray(null, (bool[])value); return; }
-                    case BuiltInType.SByte: { WriteSByteArray(null, (sbyte[])value); return; }
-                    case BuiltInType.Byte: { WriteByteArray(null, (byte[])value); return; }
-                    case BuiltInType.Int16: { WriteInt16Array(null, (short[])value); return; }
-                    case BuiltInType.UInt16: { WriteUInt16Array(null, (ushort[])value); return; }
-                    case BuiltInType.Int32: { WriteInt32Array(null, (int[])value); return; }
-                    case BuiltInType.UInt32: { WriteUInt32Array(null, (uint[])value); return; }
-                    case BuiltInType.Int64: { WriteInt64Array(null, (long[])value); return; }
-                    case BuiltInType.UInt64: { WriteUInt64Array(null, (ulong[])value); return; }
-                    case BuiltInType.Float: { WriteFloatArray(null, (float[])value); return; }
-                    case BuiltInType.Double: { WriteDoubleArray(null, (double[])value); return; }
-                    case BuiltInType.String: { WriteStringArray(null, (string[])value); return; }
-                    case BuiltInType.DateTime: { WriteDateTimeArray(null, (DateTime[])value); return; }
-                    case BuiltInType.Guid: { WriteGuidArray(null, (Uuid[])value); return; }
-                    case BuiltInType.ByteString: { WriteByteStringArray(null, (byte[][])value); return; }
-                    case BuiltInType.XmlElement: { WriteXmlElementArray(null, (XmlElement[])value); return; }
-                    case BuiltInType.NodeId: { WriteNodeIdArray(null, (NodeId[])value); return; }
-                    case BuiltInType.ExpandedNodeId: { WriteExpandedNodeIdArray(null, (ExpandedNodeId[])value); return; }
-                    case BuiltInType.StatusCode: { WriteStatusCodeArray(null, (StatusCode[])value); return; }
-                    case BuiltInType.QualifiedName: { WriteQualifiedNameArray(null, (QualifiedName[])value); return; }
-                    case BuiltInType.LocalizedText: { WriteLocalizedTextArray(null, (LocalizedText[])value); return; }
-                    case BuiltInType.ExtensionObject: { WriteExtensionObjectArray(null, (ExtensionObject[])value); return; }
-                    case BuiltInType.DataValue: { WriteDataValueArray(null, (DataValue[])value); return; }
-                    case BuiltInType.Enumeration:
-                    {
-                        Array array = value as Array;
-                        WriteEnumeratedArray(null, array, array.GetType().GetElementType());
-                        return;
-                    }
-
-                    case BuiltInType.Variant:
-                    {
-                        Variant[] variants = value as Variant[];
-
-                        if (variants != null)
-                        {
-                            WriteVariantArray(null, variants);
-                            return;
-                        }
-
-                        object[] objects = value as object[];
-
-                        if (objects != null)
-                        {
-                            WriteObjectArray(null, objects);
-                            return;
-                        }
-
-                        throw ServiceResultException.Create(
-                            StatusCodes.BadEncodingError,
-                            "Unexpected type encountered while encoding an array of Variants: {0}",
-                            value.GetType());
-                    }
-                }
-            }
-
-            // write matrix.
-            else if (typeInfo.ValueRank > 1)
-            {
-                Matrix matrix = value as Matrix;
-                if (matrix != null)
-                {
-                    if (UseReversibleEncoding)
-                    {
-                        WriteVariantContents(matrix.Elements, new TypeInfo(typeInfo.BuiltInType, 1));
-                    }
-                    else
-                    {
-                        int index = 0;
-                        WriteStructureMatrix(matrix, 0, ref index, typeInfo);
-                    }
                     return;
                 }
-            }
 
-            // oops - should never happen.
-            throw new ServiceResultException(
-                StatusCodes.BadEncodingError,
-                Utils.Format("Type '{0}' is not allowed in an Variant.", value.GetType().FullName));
+                m_commaRequired = false;
+
+                // write scalar.
+                if (typeInfo.ValueRank < 0)
+                {
+                    switch (typeInfo.BuiltInType)
+                    {
+                        case BuiltInType.Boolean: { WriteBoolean(null, (bool)value); return; }
+                        case BuiltInType.SByte: { WriteSByte(null, (sbyte)value); return; }
+                        case BuiltInType.Byte: { WriteByte(null, (byte)value); return; }
+                        case BuiltInType.Int16: { WriteInt16(null, (short)value); return; }
+                        case BuiltInType.UInt16: { WriteUInt16(null, (ushort)value); return; }
+                        case BuiltInType.Int32: { WriteInt32(null, (int)value); return; }
+                        case BuiltInType.UInt32: { WriteUInt32(null, (uint)value); return; }
+                        case BuiltInType.Int64: { WriteInt64(null, (long)value); return; }
+                        case BuiltInType.UInt64: { WriteUInt64(null, (ulong)value); return; }
+                        case BuiltInType.Float: { WriteFloat(null, (float)value); return; }
+                        case BuiltInType.Double: { WriteDouble(null, (double)value); return; }
+                        case BuiltInType.String: { WriteString(null, (string)value); return; }
+                        case BuiltInType.DateTime: { WriteDateTime(null, (DateTime)value); return; }
+                        case BuiltInType.Guid: { WriteGuid(null, (Uuid)value); return; }
+                        case BuiltInType.ByteString: { WriteByteString(null, (byte[])value); return; }
+                        case BuiltInType.XmlElement: { WriteXmlElement(null, (XmlElement)value); return; }
+                        case BuiltInType.NodeId: { WriteNodeId(null, (NodeId)value); return; }
+                        case BuiltInType.ExpandedNodeId: { WriteExpandedNodeId(null, (ExpandedNodeId)value); return; }
+                        case BuiltInType.StatusCode: { WriteStatusCode(null, (StatusCode)value); return; }
+                        case BuiltInType.QualifiedName: { WriteQualifiedName(null, (QualifiedName)value); return; }
+                        case BuiltInType.LocalizedText: { WriteLocalizedText(null, (LocalizedText)value); return; }
+                        case BuiltInType.ExtensionObject: { WriteExtensionObject(null, (ExtensionObject)value); return; }
+                        case BuiltInType.DataValue: { WriteDataValue(null, (DataValue)value); return; }
+                        case BuiltInType.Enumeration: { WriteEnumerated(null, (Enum)value); return; }
+                    }
+                }
+
+                // write array.
+                else if (typeInfo.ValueRank <= 1)
+                {
+                    switch (typeInfo.BuiltInType)
+                    {
+                        case BuiltInType.Boolean: { WriteBooleanArray(null, (bool[])value); return; }
+                        case BuiltInType.SByte: { WriteSByteArray(null, (sbyte[])value); return; }
+                        case BuiltInType.Byte: { WriteByteArray(null, (byte[])value); return; }
+                        case BuiltInType.Int16: { WriteInt16Array(null, (short[])value); return; }
+                        case BuiltInType.UInt16: { WriteUInt16Array(null, (ushort[])value); return; }
+                        case BuiltInType.Int32: { WriteInt32Array(null, (int[])value); return; }
+                        case BuiltInType.UInt32: { WriteUInt32Array(null, (uint[])value); return; }
+                        case BuiltInType.Int64: { WriteInt64Array(null, (long[])value); return; }
+                        case BuiltInType.UInt64: { WriteUInt64Array(null, (ulong[])value); return; }
+                        case BuiltInType.Float: { WriteFloatArray(null, (float[])value); return; }
+                        case BuiltInType.Double: { WriteDoubleArray(null, (double[])value); return; }
+                        case BuiltInType.String: { WriteStringArray(null, (string[])value); return; }
+                        case BuiltInType.DateTime: { WriteDateTimeArray(null, (DateTime[])value); return; }
+                        case BuiltInType.Guid: { WriteGuidArray(null, (Uuid[])value); return; }
+                        case BuiltInType.ByteString: { WriteByteStringArray(null, (byte[][])value); return; }
+                        case BuiltInType.XmlElement: { WriteXmlElementArray(null, (XmlElement[])value); return; }
+                        case BuiltInType.NodeId: { WriteNodeIdArray(null, (NodeId[])value); return; }
+                        case BuiltInType.ExpandedNodeId: { WriteExpandedNodeIdArray(null, (ExpandedNodeId[])value); return; }
+                        case BuiltInType.StatusCode: { WriteStatusCodeArray(null, (StatusCode[])value); return; }
+                        case BuiltInType.QualifiedName: { WriteQualifiedNameArray(null, (QualifiedName[])value); return; }
+                        case BuiltInType.LocalizedText: { WriteLocalizedTextArray(null, (LocalizedText[])value); return; }
+                        case BuiltInType.ExtensionObject: { WriteExtensionObjectArray(null, (ExtensionObject[])value); return; }
+                        case BuiltInType.DataValue: { WriteDataValueArray(null, (DataValue[])value); return; }
+                        case BuiltInType.Enumeration:
+                        {
+                            Array array = value as Array;
+                            WriteEnumeratedArray(null, array, array.GetType().GetElementType());
+                            return;
+                        }
+
+                        case BuiltInType.Variant:
+                        {
+                            Variant[] variants = value as Variant[];
+
+                            if (variants != null)
+                            {
+                                WriteVariantArray(null, variants);
+                                return;
+                            }
+
+                            object[] objects = value as object[];
+
+                            if (objects != null)
+                            {
+                                WriteObjectArray(null, objects);
+                                return;
+                            }
+
+                            throw ServiceResultException.Create(
+                                StatusCodes.BadEncodingError,
+                                "Unexpected type encountered while encoding an array of Variants: {0}",
+                                value.GetType());
+                        }
+                    }
+                }
+
+                // write matrix.
+                else if (typeInfo.ValueRank > 1)
+                {
+                    Matrix matrix = value as Matrix;
+                    if (matrix != null)
+                    {
+                        if (UseReversibleEncoding)
+                        {
+                            WriteVariantContents(matrix.Elements, new TypeInfo(typeInfo.BuiltInType, 1));
+                        }
+                        else
+                        {
+                            int index = 0;
+                            WriteStructureMatrix(matrix, 0, ref index, typeInfo);
+                        }
+                        return;
+                    }
+                }
+
+                // oops - should never happen.
+                throw new ServiceResultException(
+                    StatusCodes.BadEncodingError,
+                    Utils.Format("Type '{0}' is not allowed in an Variant.", value.GetType().FullName));
+            }
+            finally
+            {
+                m_inVariantWithEncoding = false;
+            }
         }
         #endregion
 
@@ -2383,7 +2393,7 @@ namespace Opc.Ua
         /// </summary>
         public void WriteObjectArray(string fieldName, IList<object> values)
         {
-            if (values == null || values.Count == 0)
+            if (values == null || (values.Count == 0 && !m_inVariantWithEncoding))
             {
                 WriteSimpleField(fieldName, null, false);
                 return;
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/XmlDecoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/XmlDecoder.cs
index 6406f3b1af..4d1a03f682 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/XmlDecoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/XmlDecoder.cs
@@ -1403,9 +1403,16 @@ namespace Opc.Ua
         /// </summary>
         public ExtensionObject ReadExtensionObject(string fieldName)
         {
-            if (!BeginField(fieldName, true))
+            bool isNil;
+
+            if (!BeginField(fieldName, true, out isNil))
             {
-                return null;
+                if (isNil)
+                {
+                    return null;
+                }
+
+                return ExtensionObject.Null;
             }
 
             PushNamespace(Namespaces.OpcUaXsd);
diff --git a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
index 8693a1edf6..6d1fe53498 100644
--- a/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
+++ b/Stack/Opc.Ua.Core/Types/Encoders/XmlEncoder.cs
@@ -437,7 +437,12 @@ namespace Opc.Ua
         /// </summary>
         public void WriteString(string fieldName, string value)
         {
-            if (BeginField(fieldName, value == null, true))
+            WriteString(fieldName, value, false);
+        }
+
+        private void WriteString(string fieldName, string value, bool isArrayElement)
+        {
+            if (BeginField(fieldName, value == null, true, isArrayElement))
             {
                 // check the length.
                 if (m_context.MaxStringLength > 0 && m_context.MaxStringLength < value.Length)
@@ -502,7 +507,12 @@ namespace Opc.Ua
         /// </summary>
         public void WriteByteString(string fieldName, byte[] value)
         {
-            if (BeginField(fieldName, value == null, true))
+            WriteByteString(fieldName, value, false);
+        }
+
+        private void WriteByteString(string fieldName, byte[] value, bool isArrayElement = false)
+        {
+            if (BeginField(fieldName, value == null, true, isArrayElement))
             {
                 // check the length.
                 if (m_context.MaxByteStringLength > 0 && m_context.MaxByteStringLength < value.Length)
@@ -520,7 +530,12 @@ namespace Opc.Ua
         /// </summary>
         public void WriteXmlElement(string fieldName, XmlElement value)
         {
-            if (BeginField(fieldName, value == null, true))
+            WriteXmlElement(fieldName, value, false);
+        }
+
+        private void WriteXmlElement(string fieldName, XmlElement value, bool isArrayElement)
+        {
+            if (BeginField(fieldName, value == null, true, isArrayElement))
             {
                 m_writer.WriteRaw(value.OuterXml);
                 EndField(fieldName);
@@ -1230,7 +1245,7 @@ namespace Opc.Ua
                 {
                     for (int ii = 0; ii < values.Count; ii++)
                     {
-                        WriteString("String", values[ii]);
+                        WriteString("String", values[ii], true);
                     }
                 }
 
@@ -1346,7 +1361,7 @@ namespace Opc.Ua
                 {
                     for (int ii = 0; ii < values.Count; ii++)
                     {
-                        WriteByteString("ByteString", values[ii]);
+                        WriteByteString("ByteString", values[ii], true);
                     }
                 }
 
@@ -1375,7 +1390,7 @@ namespace Opc.Ua
                 {
                     for (int ii = 0; ii < values.Count; ii++)
                     {
-                        WriteXmlElement("XmlElement", values[ii]);
+                        WriteXmlElement("XmlElement", values[ii], true);
                     }
                 }
 
diff --git a/Stack/Opc.Ua.Core/Types/Schemas/SchemaValidator.cs b/Stack/Opc.Ua.Core/Types/Schemas/SchemaValidator.cs
index 10301a1679..d833cecdf4 100644
--- a/Stack/Opc.Ua.Core/Types/Schemas/SchemaValidator.cs
+++ b/Stack/Opc.Ua.Core/Types/Schemas/SchemaValidator.cs
@@ -144,7 +144,7 @@ namespace Opc.Ua.Schema
         /// <summary>
         /// Loads the dictionary from a file.
         /// </summary>
-        protected object Load(System.Type type, string namespaceUri, string path)
+        protected object Load(System.Type type, string namespaceUri, string path, Assembly assembly = null)
         {
             // check if already loaded.
             if (m_loadedFiles.ContainsKey(namespaceUri))
@@ -178,7 +178,7 @@ namespace Opc.Ua.Schema
                 }
 
                 // load embedded resource.
-                return LoadResource(type, location, null);
+                return LoadResource(type, location, assembly);
             }
 
             if (!String.IsNullOrEmpty(path))
@@ -186,7 +186,7 @@ namespace Opc.Ua.Schema
                 if (!File.Exists(path))
                 {
                     // load embedded resource.
-                    return LoadResource(type, path, null);
+                    return LoadResource(type, path, assembly);
                 }
 
                 // check for file in the same directory as the input file.
diff --git a/Tests/Opc.Ua.Core.Tests/Types/Encoders/EncoderCommon.cs b/Tests/Opc.Ua.Core.Tests/Types/Encoders/EncoderCommon.cs
index 42820cf081..32a03365b1 100644
--- a/Tests/Opc.Ua.Core.Tests/Types/Encoders/EncoderCommon.cs
+++ b/Tests/Opc.Ua.Core.Tests/Types/Encoders/EncoderCommon.cs
@@ -209,11 +209,14 @@ namespace Opc.Ua.Core.Tests.Types.Encoders
             Encode(encoder, builtInType, builtInType.ToString(), expected);
             Dispose(encoder);
             var buffer = encoderStream.ToArray();
-            string jsonFormatted;
+            string formatted;
             switch (encoderType)
             {
                 case EncodingType.Json:
-                    jsonFormatted = PrettifyAndValidateJson(Encoding.UTF8.GetString(buffer));
+                    formatted = PrettifyAndValidateJson(Encoding.UTF8.GetString(buffer));
+                    break;
+                default:
+                    formatted = Encoding.UTF8.GetString(buffer);
                     break;
             }
             var decoderStream = new MemoryStream(buffer);