A model is the representation of a host application's connections, screens, navigation, and data flow that you build with the Verastream Host Integrator Design Tool. Once you have modeled your host application, you deploy the resulting model to a Host Integrator Server, where it can provide real-time access to host data through web-enabled services.
Building a good model of a host application requires a basic understanding of the business problem that will be solved using the Host Integrator model and associated components. Use the guidelines below to prepare for Verastream host application modeling.
Know the host operating system and any relevant details about the host application software. The more you know about your host application, the greater the likelihood that you'll have an effective, robust model.
If you're not familiar with the host application yourself, a host application
programmer or an experienced business user needs to identify logon procedures
and the sequence of screens typically used to reach the data you want to
access. As you build the host application model, each host screen used in
the model is represented as an entity. An efficient host application model
contains only as many entities as are required to perform the necessary
transactions between the external application and the host application.
Take the time to create an easy-to-follow data map to simplify the process of building the model. This exercise may reveal multiple screens and operations that display the same data. Whenever possible, model the screen that shows the data in its updated form for the transaction in question.
Will the host data be presented on a web page for customers or users? Is the host data to be used by another application? Know the requirements and the environment where the host data will be used. If you are only planning to update the host application with a more modern web page look and feel, you can build a simple model. However, if you plan to alter the work flow or interoperate directly with other applications, your model will need to be more complex.
Host Integrator provides APIs for integrating host data through SQL, ASP, ASP.NET, JSP, Web Services, EJB, COM, and .NET. For a quick implementation, many of these options can be generated using Host Integrator's Web Builder.
Error handling is a very important part of the model-planning process. Learn where and how the model can fail or put the host application in an error condition. Then, build exception handling into your model for these cases to reduce the chance that your model will fail after it is deployed.