ModuleBase Class

The base class for XAF modules.

Assembly : DevExpress.ExpressApp.v25.2.dll

NuGet Package : DevExpress.ExpressApp

Declaration

C#
VB.NET

csharp

public class ModuleBase :
    Component,
    ISupportSetup

Public Class ModuleBase
    Inherits Component
    Implements ISupportSetup

The following members return ModuleBase objects:

ModuleBase.CreateModule(Type, ModelStoreBase)

Remarks

The presence of a ModuleBase class descendant in a standard Class Library project indicates that this is a module project.

You can use modules to customize the Application Model when it is being loaded.

Collect Types Declared Within the Module: Performance Optimization

XAF uses reflection to collect all types declared in the current module. To optimize type collection in your application, override the following methods:

GetDeclaredExportedTypes(). Collects business classes available in the assembly and exports them to the Application Model.
GetDeclaredControllerTypes(). Collects Controllers available in the assembly and exports them to the Application Model.
GetRegularTypes(). Collects built-in types required (business objects, DbContext descendants, Controllers, List and Property Editors, and others).

Note

If you override the GetRegularTypes method, XAF stops collecting the types declared in the module and you need to register each new Business Object, Controller, or Editor in this method. However, you do not need to register types that are already returned by overridden GetDeclaredExportedTypes and GetDeclaredControllerTypes methods.

RegisterEditorDescriptors(). Use it to disable reflection.

Load Additional Modules

Use the GetRequiredModuleTypesCore method to add the required modules to the Application Model together with the current module. The current module should have a reference to the modules that you want to add.

Add Custom Nodes and Properties

Override the ModuleBase.ExtendModelInterfaces method to add required nodes or properties. If you need to add a custom node, first declare its interface by inheriting from IModelNode. For more information, see Extend and Customize the Application Model in Code.

Update the Application Model Using the Generator Updaters

Override the ModuleBase.AddGeneratorUpdaters method to add Generator Updaters that update the Application Model.

Add External Business Objects and Controllers to the Application Model

Override the GetDeclaredControllerTypes and GetDeclaredExportedTypes methods as displayed in the following code snippet:

csharp

namespace MySolution.Module {  
    public sealed partial class MySolutionModule : ModuleBase {  
        protected override IEnumerable<Type> GetDeclaredControllerTypes() {  
            var originalList = (Type[])base.GetDeclaredControllerTypes();  
            var newList = originalList.ToList();  
            newList.Add(typeof(ClassLibrary1.CustomController));  
            return newList;  
        }  
        protected override IEnumerable<Type> GetDeclaredExportedTypes() {  
            var originalList = base.GetDeclaredExportedTypes();  
            var newList = originalList.ToList();  
            newList.Add(typeof(ClassLibrary1.MyCustomTask));  
            return newList;  
        }  
    }  
}

Update the Database Using Module Updaters

Override the ModuleBase.GetModuleUpdaters method to add ModuleUpdater objects that update the database.

Customize Type Information

Override the ModuleBase.CustomizeTypesInfo method to customize information about a particular class or property before it is loaded to the Application Model. For more information, refer to the following topic: Use Metadata to Customize Business Classes Dynamically.

Register a List or Property Editor

Override the protected RegisterEditorDescriptor method to disable the reflection mechanism that collects information about types decorated by ListEditorAttribute and PropertyEditorAttribute. This expedites application startup.

Note

In this case, Editors that are decorated by ListEditorAttribute and PropertyEditorAttribute are not registered.

Use EditorDescriptorsFactory.RegisterListEditorAlias and EditorDescriptorsFactory.RegisterListEditor methods to register your List Editor with its alias.

To register a Property Editor, use EditorDescriptorsFactory.RegisterPropertyEditorAlias and EditorDescriptorsFactory.RegisterPropertyEditor methods.

You can associate an EditorAliases enumerator value or a custom alias with a target type. You can register one alias for WinForms and ASP.NET Core Blazor Editors in the base module project and locate corresponding Editors in platform-dependent projects. If you use platform-agnostic Editors for certain types, specify a string alias to use them in a platform-independent module.

Note

The Editor registered for the Object type serves as a fallback/default editor for objects and properties not associated with a specific Editor type.

The following example registers a default List Editor:

csharp

public class MyModule : ModuleBase {
    //...
    protected override void RegisterEditorDescriptors(EditorDescriptorsFactory 
    editorDescriptorsFactory) {
        editorDescriptorsFactory.RegisterListEditorAlias("CustomListEditorAlias",
        typeof(object), true);
        editorDescriptorsFactory.RegisterListEditor("CustomListEditorAlias", 
        typeof(object), typeof(GridListEditor), true);
    }
}

The list below describes how to customize this example.

Pass type Object as the elementType parameter and false as the isDefaultEditor parameter. The method add the Editor to the IModelViews.DefaultListEditor list. This enables this Editor in the Model Editor.
To register the default List Editor for objects of a specific type, pass the target type to the methods’ elementType parameter and set the isDefaultEditor parameter to true to mark this Editor as the default editor for this type.
Pass a type as the elementType parameter and false as the isDefaultEditor parameter. The method adds the List Editor to the IModelClass.EditorType list for the specified type. This allows you to choose this Editor in the Model Editor.
Use the classHandler parameter of the RegisterListEditorAlias method if you want to register a number of Editors for one type and choose an editor according to custom logic. The editor that matches the specified conditions is applied to the current type first.

The following example registers a default Property Editor:

csharp

public class MyModule : ModuleBase {
    //...
    protected override void RegisterEditorDescriptors(EditorDescriptorsFactory 
    editorDescriptorsFactory) {
        //...
        editorDescriptorsFactory.RegisterPropertyEditorAlias("CustomPropertyEditorAlias",
        typeof(object), true);
        editorDescriptorsFactory.RegisterPropertyEditor("CustomPropertyEditorAlias", 
        typeof(object), typeof(DefaultPropertyEditor), true);
    }
}

Note

To set a Property Editor as default for properties with protected content, implement the IProtectedContentEditor interface in the Property Editor.

The list below describes how you can modify this example.

Pass type Object as the elementType parameter and false as the isDefaultEditor parameter. The method adds the Editor to the IModelRegisteredViewItem.DefaultItemType list of default Property Editors or the IModelRegisteredPropertyEditors.ProtectedContentPropertyEditor list if your Editor is for the properties with protected content. This allows you to choose this Editor in the Model Editor.
To register the default Property Editor for the properties of a specific type, pass the target type to the methods’ elementType parameter and set the isDefaultEditor parameter to false to mark this Editor as the default editor for this type.
Specify the target type in the methods’ elementType parameter and set the isDefaultEditor parameter to false to add the Property Editor to the IModelRegisteredPropertyEditor.EditorType list of Property Editors for the specified type. Then, you can choose this Editor in the Model Editor.
Use the memberHandler parameter of the RegisterPropertyEditorAlias method if you want to register a number of Editors for properties of one type and choose the appropriate Editor according to the logic implemented in it. In different situations, the Editor satisfying the conditions is applied to current type first. Editors registered with this parameter have priority over Editors registered without it. For the Editor registered with the memberHandler parameter, the new node is created in the Model Editor’s View Items | PropertyEditors node.

You do not have to create instances of ModuleBase class descendants. They are created automatically.

Add External Business Objects and Controllers to the Application Model

XAF uses reflection to collect classes and Controllers from each module and build an Application Model. Use the following techniques to customize this process:

Use the ModuleBase.AdditionalControllerTypes and ModuleBase.AdditionalExportedTypes properties to specify business classes and Controllers that should be loaded to the Application Model:
Override the GetDeclaredControllerTypes and GetDeclaredExportedTypes methods of the ModuleBase class to add external business objects and Controllers to the Application Model:

Replace Data Model Classes in a Built-In Module

If you want to use a custom entity type in a built-in module, configure this type in the Application Builder’s module settings. For more information on how to do this, refer to the following topic: Modules.