dslVersion - How to increment but still support older versions?

Tech: Visual Studio 2010, Visual Studio Visualization & Modeling SDK

We have a commercial Visual Studio 2010 DSL, when we release a new version we want to increment the version number. I open the DslDefinition.dsl and update the version number as required and then do a Transform all templates so that the changes get reflected. The DslPackage 'source.extension.vsixmanifest' gets updated fine and shows the new version number.

The issue is however is that when someone opens a model created from version 1.0.0.0 with the updated version 1.0.0.1 then they can't open the model, the reason seems to be that the 'dslVersion' in the *.diagram file is set to 1.0.0.0 which has been outdated, I can fix by manually updati开发者_JS百科ng the dslVersion but there seems to be no way to set a supported version range.

Is there any fix for this?

I have solved this issue by overriding the 'CheckVersion' method which sits in the '*SerializationHelper' class. My implementation is below.

     partial class ProductSerializationHelper
    {
        protected override void CheckVersion(Microsoft.VisualStudio.Modeling.SerializationContext serializationContext, System.Xml.XmlReader reader)
        {
            #region Check Parameters
            global::System.Diagnostics.Debug.Assert(serializationContext != null);
            if (serializationContext == null)
                throw new global::System.ArgumentNullException("serializationContext");
            global::System.Diagnostics.Debug.Assert(reader != null);
            if (reader == null)
                throw new global::System.ArgumentNullException("reader");
            #endregion

            global::System.Version expectedVersion = new global::System.Version("2.5.0.0");
            string dslVersionStr = reader.GetAttribute("dslVersion");
            if (dslVersionStr != null)
            {
                try
                {
                    global::System.Version actualVersion = new global::System.Version(dslVersionStr);

// #### THIS IS WHERE I CHANGED FROM '!=' to '>'
                    if (actualVersion > expectedVersion)
                    {
                        ProductSerializationBehaviorSerializationMessages.VersionMismatch(serializationContext, reader, expectedVersion, actualVersion);
                    }
                }
                catch (global::System.ArgumentException)
                {
                    ProductSerializationBehaviorSerializationMessages.InvalidPropertyValue(serializationContext, reader, "dslVersion", typeof(global::System.Version), dslVersionStr);
                }
                catch (global::System.FormatException)
                {
                    ProductSerializationBehaviorSerializationMessages.InvalidPropertyValue(serializationContext, reader, "dslVersion", typeof(global::System.Version), dslVersionStr);
                }
                catch (global::System.OverflowException)
                {
                    ProductSerializationBehaviorSerializationMessages.InvalidPropertyValue(serializationContext, reader, "dslVersion", typeof(global::System.Version), dslVersionStr);
                }
            }
        }
    }