Presentation Data Model

One of the most common presentation layer design patterns is Model – View – Controller (MVC), which separates layout, behavior and the data model aspects of the presentation layer. This generator helps building a rich data model for the presentation layer based on Xomega Framework - a powerful open-source framework for building multitier WPF or Silverlight applications.

One of the most important features of this generator is that it uses the structure of the service layer to generate the presentation data model rather than the actual structure of the business layer, which could be significantly different. This allows generating a presentation data model that is much more appropriate for the user interface. Indeed, if you think of it, the presentation layer is communicating with the service layer to read the data or make changes to the data and therefore should be based on the structure of the service layer.

However, a single form can be using multiple service operations for reads and updates, so its structure will have to combine the structures of the operations it is using. Xomega object model allows declaring a presentation data object and indicate the parts of operation structures that it should consist of.

For example, let’s assume that we have an Order Details form that has a OrderObject as a data model. To read the data and to make changes the form will be calling Read and Update service operations on a Order Business Object. The structures of these two operations may be similar but not identical and also potentially different from the structure of the underlying Order Business Object. For the OrderObject to be able to hold the data that has been read or will be sent for updates, it needs to combine the sets of parameters for both operations. If two parameters have the same name, they will result in generation of a single property as long as they have the same type.

The generator takes all presentation objects defined in the model and generates partial classes that subclass base Xomega data objects and have a set of Xomega data properties as specified in the model. The types of data properties will be based on the logical types of the corresponding parameters and the mappings between the logical types to the Xomega data properties as specified in their configurations.

The generated data objects can be regenerated at any time whenever the object model is changed. Therefore, the generated files should never be edited manually and all additional functionality needs to be implemented in the partial classes that are located in separate files.