Templates and instances

Before you start modeling your application using the Application Server, you must understand templates and object instances.

Templates are elements in Application Server that contain common configuration parameters for object instances that you use multiple times in your application.

For example, you might create a template for valves. You configure the template with all the unique attributes for valves. You use that template to make object instances of valves. You can further configure and customize each object instance to represent a specific valve.

Object instances are the specific devices in your environment, such as diaphragm valves or very complex devices, like a reactor. You create an instance from a template and then customize the specific instance as needed.

Instances are deployed to the runtime environment. Templates exist in the development environment and cannot be deployed.

Creating templates and instances is very similar to object-oriented programming. For example, templates and instances have a parent/child relationship that involves inheriting attributes. There are differences, however, between object-oriented programming and creating templates and instances in Application Server.

Collectively, templates and instances are called objects. The following graphic shows the different kinds of objects and how they are organized.

If you are new to this kind of programming, the next section explains the basic concepts you need to know before you start. If you are familiar with object-oriented programming, the concepts in the next section may be familiar to you, but notice the important differences between object-oriented programming and Application Server.