How to Migrate EXTRA! Programs to VHI

By migrating EXTRA! terminal emulation applications to Host Integrator's powerful integration platform, you make them available to Web applications, mobile apps, and SOA Web services. Host Integrator contains a .NET class library, EXTRA! COM, that is also accessible through a COM interface and provides you with the ability to do just that.

The EXTRA! COM library currently supports only 3270 terminal type sessions.

The classes, methods, and properties that comprise the EXTRA! COM HLLAPI Adapter are documented in a MSDN-style compiled help system that is included with Verastream Host Integrator.

Migrating VB.NET or C# Programs

  1. In your .NET EXTRA program, remove the reference to the EXTRA! library, and add a reference to both the EXTRA! COM library and the .NET connector:
    %VHI_ROOT%\lib\dotnet\Attachmate.Verastream.HostIntegrator.E2V.dll
    %VHI_ROOT%\lib\dotnet\WRQ.Verastream.HostIntegrator.dll
    
  2. In your code, add using directives for these classes. The type "Screen" exists in both connectors. To remedy this confusion, use an using alias directive:
    using Attachmate.Verastream.HostIntegrator.E2V;
    using Screen = Attachmate.Verastream.HostIntegrator.E2V.Screen;
    using WRQ.Verastream.HostIntegrator;
    
  3. In the VHI Design Tool, create a model that connects to the same host and port as the EXTRA! program. Leave the model empty (no entities) to get started.
  4. Deploy the model.
  5. Change your program to call Sessions.open with the model name.
  6. Compile and debug your code.

Migrating Microsoft Office Visual Basic for Applications (VBA) Programs

The COM interface to the EXTRA! COM library is not based on the Verastream Host Integrator COM connector. It is a .NET class library. While it is possible to use both the EXTRA! COM interface and the Host Integrator COM connector in your VBA program, these two connectors are unrelated; you cannot share sessions between the two. Microsoft Office VBA interfaces use COM; if you are not using Microsoft Office VBA, we recommend the use of .NET because it offers more flexibility.

  1. In your Microsoft Office VBA program, remove the reference to the EXTRA! library, and add a reference to the EXTRA! COM library:
    %VHI_ROOT%\lib\dotnet\Attachmate.Verastream.HostIntegrator.E2V.tlb
  2. In the VHI Design Tool, create a model that connects to the same host and port as the EXTRA! program. Leave the model empty (no entities) to get started.
  3. Deploy the model.
  4. Change your program to call Sessions.open with the model name.
  5. Compile and debug your code.

What do I need to watch out for?

Depending on the situation, you may have to make additional changes to the EXTRA! client program, see Troubleshooting Your Migration.

Related Topics
Bullet Troubleshooting Your Migration
Bullet About Migrating EXTRA! Extreme 9.3 Applications to Verastream Host Integrator
Bullet Model Debug Messages
Bullet Host Integrator API Introduction
Bullet .NET Application Requirements