The OERA Presentation layer communicates with the Common Infrastructure and Business Components layers; the latter communication happens via a Service Adapter which talks to the relevant Service Interface. The Progress Communities Architecture, SaaS & Cloud Computing community has more information on the OERA, including a variety of documents and discussions.
Broadly speaking, the Presentation layer interacts with the Business Component and Common Infrastructure layers.
The interaction between the individual elements of the MVP pattern, as well as their interactions with other OERA component is shown below.
The OERA recommends the use of the Model-View-Presenter (MVP) pattern for the design of a Presentation Layer's code.
Model View Presenter Architecture
The Service Adapter handles Presentation Layer service requests. The Presentation Layer may use more than one Service Adapter and uses Common Infrastructure components to discover and manage Service Adapters. The Model and Presenter uses the ServiceMessageManager to manage communication with the Service Adapter.
Service Message Architecture
Data Request Flows
The root package for all presentation layer components is OpenEdge.PresentationLayer. The code is structured according to these general principles.