UI Model

All the information that the eXpressApp Framework uses to build user interfaces comes from the Application Model. For instance, when the framework creates a grid editor that displays a list of Contact objects, information for each column's visibility, location, caption and other settings is taken from the Application Model. When you run an application project (Windows Forms or ASP.NET application), the Application Model is created and then used to create UI elements. The Application Model provides details on business classes, Controllers, Actions, Property Editors and other elements that provide or influence application functionality.

All the information loaded to the Application Model is represented as metadata - data defined via a neutral format that can be adapted to any target platform. Thus, the Application Model represents one the mechanisms that enable UI-independent code to be used.

Initially, Application Model information is collected from code. You can customize and extend this information in code of your own eXpressApp Framework modules. The resulting Application Model can be customized at design time via the Model Editor. The changes made at design time are saved to definition files. You can produce these files in any project in your application. For instance, you can make UI-specific changes by customizing the Model in appropriate UI-specific projects. Moreover, an application's administrator can invoke the Model Editor and make required changes as well. As a result, when the application runs, all the changes saved to definition files are applied to the Application Model in a certain order. The changes made by end-user can also be saved to a separate definition file. This file is read last when the application runs. The multi-layer structure of the Application Model allows a developer, application administrator and end-user to customize the application independently.

The Model Editor is a tool that runs directly inside Visual Studio or at runtime as a separate window, and allows you to edit model information. It has a lot of advanced functionality helping you provide the required customizations.