BHoM_Engine: Fix issues with system types from newer runtimes to older

BHoM_Engine/Create/Type/GenericType.cs

@@ -1,7 +1,7 @@
 /*
  * This file is part of the Buildings and Habitats object Model (BHoM)
  * Copyright (c) 2015 - 2025, the respective contributors. All rights reserved.
  *
  * Each contributor holds copyright over their respective contributions.
  * The project versioning (Git) records all such contribution source information.
  *                                           
@@ -142,7 +142,11 @@
             }
             //Main type definition as string up until the first split char (first '<').
             //Number of generic arguments will be 1 less than the number of argsSplit count
-            return GenericType(name.Substring(0, argsSplit[0]) + "`" + (argsSplit.Count - 1), arguments, silent, takeFirstIfMultiple);
+            Type type = GenericType(name.Substring(0, argsSplit[0]) + "`" + (argsSplit.Count - 1), arguments, silent, takeFirstIfMultiple);
+
+            if (type != null && name.Contains("&"))
+                type = type.MakeByRefType();
+            return type;
         }
 
         /***************************************************/
@@ -209,9 +213,12 @@
                 arguments.Add(name.Substring(argsStarts[i], argsEnd[i] - argsStarts[i]).Trim());
             }
             string mainName = name.Substring(0, nameEnd);
-            //Main type definition as string up until the first split char (first '<').
+            //Main type definition as string up until the first split char (first '[[').
             //Number of generic arguments will be 1 less than the number of argsSplit count
-            return GenericType(mainName, arguments, silent, takeFirstIfMultiple);
+            Type type = GenericType(mainName, arguments, silent, takeFirstIfMultiple);
+            if (type != null && name.Contains("&"))
+                type = type.MakeByRefType();
+            return type;
         }
 
         /***************************************************/

BHoM_Engine/Create/Type/Type.cs

@@ -1,7 +1,7 @@
 /*
  * This file is part of the Buildings and Habitats object Model (BHoM)
  * Copyright (c) 2015 - 2025, the respective contributors. All rights reserved.
  *
  * Each contributor holds copyright over their respective contributions.
  * The project versioning (Git) records all such contribution source information.
  *                                           
@@ -49,6 +49,13 @@
                 return null;
             }
 
+            if (name.StartsWith("System.")) //If a system type, try create it before doing anything else. If failing, rest of method will handle unqualified, generics, reference etc
+            {
+                Type type = System.Type.GetType(name);
+                if (type != null)
+                    return type;
+            }
+
             if (name.Contains('<'))
                 return GenericTypeAngleBrackets(name, silent, takeFirstIfMultiple);
             else if (name.Contains('`') && name.Contains("[["))
@@ -67,9 +74,9 @@
                 if (type == null)
                     type = System.Type.GetType(unQualifiedName);    //Fallback for when deserialising a type from a later net runtime to a lower net runtime. Can be critical when going between softwares of different net runtimes.
 
-                if (type == null && name.EndsWith("&"))
+                if (type == null && name.Contains("&"))
                 {
-                    type = Type(name.TrimEnd(new char[] { '&' }), true);
+                    type = Type(name.Replace("&", ""), silent, takeFirstIfMultiple);
                     if (type != null)
                         type = type.MakeByRefType();
                 }
@@ -103,7 +110,10 @@
             ["System.Drawing.Bitmap"] = typeof(System.Drawing.Bitmap),
             ["System.Collections.Generic.SortedDictionary`2"] = typeof(System.Collections.Generic.SortedDictionary<,>),
             ["System.Data.DataTable"] = typeof(System.Data.DataTable),
-            ["System.Collections.Generic.HashSet`1"] = typeof(System.Collections.Generic.HashSet<>)
+            ["System.Collections.Generic.HashSet`1"] = typeof(System.Collections.Generic.HashSet<>),
+            ["System.Xml.XmlNode"] = typeof(System.Xml.XmlNode),
+            ["System.Xml.Linq.XDocument"] = typeof(System.Xml.Linq.XDocument),
+            ["System.Collections.Concurrent.ConcurrentBag`1"] = typeof(System.Collections.Concurrent.ConcurrentBag<>)
         };
 
         /*******************************************/

Serialiser_Engine/Compute/Deserialise/Type.cs

@@ -1,7 +1,7 @@
 /*
  * This file is part of the Buildings and Habitats object Model (BHoM)
  * Copyright (c) 2015 - 2025, the respective contributors. All rights reserved.
  *
  * Each contributor holds copyright over their respective contributions.
  * The project versioning (Git) records all such contribution source information.
  *                                           
@@ -38,7 +38,7 @@
         /*******************************************/
         /**** Private Methods                   ****/
         /*******************************************/
-        
+
         private static Type DeserialiseType(this BsonValue bson, Type value, string version, bool isUpgraded)
         {
             // Handle the case where the type is represented as a string
@@ -146,16 +146,10 @@
             Type type = null;
             if (fullName == "T")
                 return null;
-            if (fullName.IsOmNamespace())
-                type = Base.Create.Type(fullName, true, true);
             else if (fullName.IsEngineNamespace())
                 type = Base.Create.EngineType(fullName, true, true);
             else
-            {
-                type = Type.GetType(fullName);
-                if (type == null)
-                    type = System.Type.GetType(Base.Query.UnqualifiedName(fullName));
-            }
+                type = Base.Create.Type(fullName, true, true);  //Use for all cases except engine methods as method able to handle both oM, and system types, as well as adapter. Also this method is called no matter what if the type is serialised as a string rather than document in this file
 
             if (type == null)
             {