[Feature] Copy objects from live Server to offline (design mode) Server

[christianitis]

It would be really great if there were a way to transfer object definitions from a live server to an offline server.
My use case is that I am designing an application which allows users to compile many database objects from different instances into a single hierarchy, then generate a script to create that hierarchy on an arbitrary instance of SQL Server.
To accomplish this, I was hoping to add the online objects selected by the user to an offline (design mode) Server, then use SMO's scripting capabilities to script the entire tree to a .sql file.

For example:

var onlineServerConnection = new ServerConnection(new SqlConnection(/* ... */));
var onlineServer = new Server(onlineServerConnection);
var onlineDatabase = onlineServer.Databases["SmoTestDatabaseOnline"];
var onlineTable = onlineDatabase.Tables["SmoTestTable"];

var offlineServerConnection = new ServerConnection { ServerVersion = new ServerVersion(15, 0), TrueName = "designMode" };
var offlineServer = new Server(offlineServerConnection);
(offlineServer as ISfcHasConnection).ConnectionContext.Mode = SfcConnectionContextMode.Offline;
var offlineDatabase = new Database
{
	Parent = offlineServer,
	Name = "SmoTestDatabaseOffline"
};
onlineTable.Parent = offlineDatabase;
offlineDatabase.Tables.Add(onlineTable);
offlineServer.Databases.Add(offlineDatabase);

But I'm met with Microsoft.SqlServer.Management.Smo.FailedOperationException: SetParent failed for Table 'dbo.SmoTestTable'. ---> Microsoft.SqlServer.Management.Smo.InvalidSmoOperationException: Cannot perform the operation on this object, because the object is a member of a collection..
If I remove the onlineTable.Parent = offlineDatabase;, I am instead met with Microsoft.SqlServer.Management.Smo.FailedOperationException: Parent property of object [dbo].[SmoTestTable] does not match the collection's parent to which it is added.

I also attempted to use the Transfer class to accomplish this, but was met with Microsoft.SqlServer.Management.Common.TransferException: An error occurred while transferring data. See the inner exception for details. ---> Microsoft.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

var onlineDatabase = onlineServer.Databases["SmoTestDatabaseOnline"];
var onlineTable = onlineDatabase.Tables["SmoTestTable"];

//--------------------------------------------------

var transfer = new Transfer(onlineDatabase)
{
	DestinationServer = offlineServer.Name,
	DestinationDatabase = offlineDatabase.Name,
	CopyAllObjects = false,
	CopySchema = true
};
transfer.ObjectList.Add(onlineTable);
transfer.TransferData();

offlineServer.Refresh();
offlineDatabase.Refresh();

As it stands, the only conceivable way to accomplish what I want to do would be to create a new Table object and individually copy all properties onlineTable to it. But this is cumbersome and prone to error.

[shueybubbles]

I don't think there's any feature to enable this exact scenario.
I think the best you could do is to create a Transfer or ScriptPublishModel instance for each of the active servers with a custom ISmoScriptWriter implementation that combines the output. Your custom writer would be responsible for merging the source scripts to maintain dependency ordering.