Built-in Business Classes & Interfaces
- 5 minutes to read
The XAF features the Business Class Library with interfaces for XAF modules and the interface implementations for supported ORMs (XPO and EF Core).
The Business Class Library consists of the following assemblies:
| Assembly | Description |
|---|---|
| DevExpress.Persistent.BaseImpl.Xpo.v24.2.dll | Contains ready-to-use XPO persistent classes. |
| DevExpress.Persistent.BaseImpl.EFCore.v24.2.dll | Contains ready-to-use Entity Framework Core classes. |
| DevExpress.Persistent.Base.v24.2.dll | Contains interfaces and helper classes used in XAF Additional Modules. Classes implementing these interfaces are available in the DevExpress.Persistent.BaseImpl.* assemblies listed above. |
Interfaces for XAF Modules
Assembly: DevExpress.Persistent.Base.v24.2.dll
Use service interfaces from the DevExpress.Persistent.Base.v24.2.dll assembly to integrate your business classes to XAF modules like Security System.
Examples:
- Implement a Custom Security System User Based on an Existing Business Class
- Implement Custom Security Objects (Users, Roles, Operation Permissions)
- How to: Store file attachments in the file system instead of the database (XPO)
- Attach Files to Objects
- How to: Add a Custom Column to the Reports List
- Display a Tree List using the ITreeNode Interface
- Display a Tree List using the HCategory Class
- How to: Use Notifications with a Custom Business Class (Implement ISupportNotifications)
- Implement Custom Rules
Interface Implementations for Supported ORMs
Assemblies:
- DevExpress.Persistent.BaseImpl.Xpo.v24.2.dll
- DevExpress.Persistent.BaseImpl.EFCore.v24.2.dll
The Business Class Library allows you to do the following:
- Use classes from the DevExpress.Persistent.BaseImpl***.24.2.dll assemblies.
- Extend persistent classes from the DevExpress.Persistent.BaseImpl***.24.2.dll assemblies to add custom functionality.
- Use the DevExpress.Persistent.BaseImpl***.24.2.dll assembly sources (shipped with the XAF installation) as an example when developing your own business class library. In addition, you can modify the sources and recompile this assembly if required. Source files are located at the following path: %PROGRAMFILES%\DevExpress 24.2\Components\Sources\DevExpress.Persistent\.
- The Business Class Library assemblies do not have references to other XAF assemblies. This allows you to use services defined there (like validation, audit trail, etc.) in non-XAF applications.
To add a class from the Business Class Library to the UI construction process, use the ModuleBase.AdditionalExportedTypes property, or use the Exported Types section of the Module Designer.
Use the Business Class Library Customization Module to change the UI settings of the Business Class Library classes.
Business Class Library Customization Module
The Business Class Library Customization module includes UI settings (Application Model differences) for XPO and Entity Framework Core classes from the Business Class Library. It specifies class icons, List View column arrangements, and Detail View layouts. To apply settings from this module, invoke the Application Designer and drag the BusinessClassLibraryCustomizationModule item from the toolbox to the Required Modules pane.
The Model Editor can override Business Class Library Customization module settings.
Note
You can add modules to your application when you use the Solution Wizard to create a new XAF solution. Select modules in the Choose Additional Modules step.
- To add an extra module in code, add it to the XafApplication.Modules or ModuleBase.RequiredModuleTypes list (adding a reference to the module assembly is insufficient).
In .NET applications, you can call the AddBusinessClassLibraryCustomization<TBuilder>(IModuleBuilder<TBuilder>) method in your ASP.NET Core Blazor/WinForms application builder.
Recompile the Business Class Library
You can modify and recompile an assembly with ready-to-use XPO or EF Core entities using the steps below.
Run the Visual Studio Command Prompt as an administrator and execute the Sn.exe (Strong Name Tool) utility with the following parameters:
sn -k "%PROGRAMFILES%\DevExpress 24.2\Components\Sources\DevExpress.Key\StrongKey.snk"This will create the strong name file (see Strong-Named Assemblies).
Navigate to one of the following folders:
- %PROGRAMFILES%\DevExpress 24.2\Components\Sources\DevExpress.Persistent\DevExpress.Persistent.BaseImpl.Xpo - if you use XPO.
- %PROGRAMFILES%\DevExpress 24.2\Components\Sources\DevExpress.Persistent\DevExpress.Persistent.BaseImpl.EFCore - if you use EF Core.
Open the DevExpress.Persistent.BaseImpl.csproj, DevExpress.Persistent.BaseImpl.EF.csproj, or DevExpress.Persistent.BaseImpl.EFCore.NetStandard.csproj project in Visual Studio.
If you use EF, ensure that the EntityFramework.dll assembly is available. You can download it from NuGet.
- Modify any class from the opened project.
Compile the project by clicking Rebuild in the context menu invoked for the solution. Once this rebuild is successful, the default assembly located in the %PROGRAMFILES%\DevExpress 24.2\Components\Bin\Framework folder will be replaced with the modified assembly.
Note
- The default path for XAF solution references is %PROGRAMFILES%\DevExpress 24.2\Components\Bin\Framework. If you use an alternate path, copy the created DevExpress.Persistent.BaseImpl.Xpo.v24.2.dll or DevExpress.Persistent.BaseImpl.EFCore.v24.2.dll assembly to the appropriate location.
- Some XPO-only modules (Audit Trail and Clone Object) have references to the DevExpress.Persistent.BaseImpl.Xpo.v24.2.dll library. If you are using these modules in your application, they must also be rebuilt. Refer to the following topic for details: How to rebuild assemblies from the source code.
Create Custom Classes with Class Names that Business Class Library Contains
If your custom business classes are named the same way as classes from the Business Class Library (for example, Person, Address, Organization, PhoneNumber), you receive the following errors:
- DuplicateModelNodeIdException at runtime or in the Model Editor.
- View layout collisions in the Model Editor.
To avoid these errors, use the ModelNodesGeneratorSettings.SetIdPrefix method as follows:
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.DC;
using DevExpress.ExpressApp.Updating;
using DevExpress.ExpressApp.Model.NodeGenerators;
namespace MySolution.Module {
public sealed partial class SolutionNameModule : ModuleBase {
public override void CustomizeTypesInfo(ITypesInfo typesInfo) {
base.CustomizeTypesInfo(typesInfo);
ModelNodesGeneratorSettings.SetIdPrefix(
typeof(MySolution.Module.BusinessObjects.Address),
"AddressEx"
);
}
}
}