protected object CreateObjectFromXml()

in src/log4net/Repository/Hierarchy/XmlHierarchyConfigurator.cs [969:1065]
78 lines of code
13 McCabe index (conditional complexity)

		protected object CreateObjectFromXml(XmlElement element, Type defaultTargetType, Type typeConstraint) 
		{
			Type objectType = null;

			// Get the object type
			string objectTypeString = element.GetAttribute(TYPE_ATTR);
			if (objectTypeString == null || objectTypeString.Length == 0)
			{
				if (defaultTargetType == null)
				{
					LogLog.Error(declaringType, "Object type not specified. Cannot create object of type ["+typeConstraint.FullName+"]. Missing Value or Type.");
					return null;
				}
				else
				{
					// Use the default object type
					objectType = defaultTargetType;
				}
			}
			else
			{
				// Read the explicit object type
				try
				{
#if NETSTANDARD1_3
					objectType = SystemInfo.GetTypeFromString(this.GetType().GetTypeInfo().Assembly, objectTypeString, true, true);
#else
					objectType = SystemInfo.GetTypeFromString(objectTypeString, true, true);
#endif
				}
				catch(Exception ex)
				{
					LogLog.Error(declaringType, "Failed to find type ["+objectTypeString+"]", ex);
					return null;
				}
			}

			bool requiresConversion = false;

			// Got the object type. Check that it meets the typeConstraint
			if (typeConstraint != null)
			{
				if (!typeConstraint.IsAssignableFrom(objectType))
				{
					// Check if there is an appropriate type converter
					if (OptionConverter.CanConvertTypeTo(objectType, typeConstraint))
					{
						requiresConversion = true;
					}
					else
					{
						LogLog.Error(declaringType, "Object type ["+objectType.FullName+"] is not assignable to type ["+typeConstraint.FullName+"]. There are no acceptable type conversions.");
						return null;
					}
				}
			}

			// Create using the default constructor
			object createdObject = null;
			try
			{
				createdObject = Activator.CreateInstance(objectType);
			}
			catch(Exception createInstanceEx)
			{
				LogLog.Error(declaringType, "XmlHierarchyConfigurator: Failed to construct object of type [" + objectType.FullName + "] Exception: "+createInstanceEx.ToString());
			}

			// Set any params on object
			foreach (XmlNode currentNode in element.ChildNodes)
			{
				if (currentNode.NodeType == XmlNodeType.Element) 
				{
					SetParameter((XmlElement)currentNode, createdObject);
				}
			}

			// Check if we need to call ActivateOptions
			IOptionHandler optionHandler = createdObject as IOptionHandler;
			if (optionHandler != null)
			{
				optionHandler.ActivateOptions();
			}

			// Ok object should be initialized

			if (requiresConversion)
			{
				// Convert the object type
				return OptionConverter.ConvertTypeTo(createdObject, typeConstraint);
			}
			else
			{
				// The object is of the correct type
				return createdObject;
			}
		}