ModelEditorGroupingHelper Class

Contains helper methods and properties that you can use to replace or customize the default grouping mechanism in the Model Editor‘s Nodes Tree.

Namespace: DevExpress.ExpressApp.ModelEditor

Assembly: DevExpress.ExpressApp.v23.2.dll

NuGet Package: DevExpress.ExpressApp

Declaration

C#

public class ModelEditorGroupingHelper

VB.NET

Public Class ModelEditorGroupingHelper

Related API Members

The following members return ModelEditorGroupingHelper objects:

• ModelEditorGroupingHelper.Instance

Remarks

The following example demonstrates how to group IModelValidationRules child nodes by a target type’s full name.

1. In the platform-agnostic Module’s constructor, access the ModelEditorGroupingHelper instance (see ModelEditorGroupingHelper.Instance) and call its RegisterNodeGroupPathDelegate. Pass the type of a node you want to regroup (IModelValidationRules) and a delegate with grouping logic (GroupPathCalculatorByNamespace) to this delegate.

   Important

   Do not customize ModelEditorGroupingHelper in multiple modules in the solution to avoid design-time issues in the Model Editor.

2. In the GroupPathCalculatorByNamespace method, return a string array where each array item is a group in the Node Tree.
3. Create an array with the UnspecifiedGroupName constant value and return it for nodes whose group path cannot be calculated for the current model node.

File: MySolution.Module\Module.cs(.vb).

C#

using DevExpress.ExpressApp; 
using DevExpress.ExpressApp.DC;
using DevExpress.ExpressApp.Model;
using DevExpress.ExpressApp.ModelEditor; 
using DevExpress.ExpressApp.Model.Core;
using DevExpress.ExpressApp.Validation;
// ...
public sealed partial class MySolutionModule : ModuleBase {
    public MySolutionModule() {
        InitializeComponent();
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(
        typeof(IModelValidationRules), node => GroupPathCalculatorByNamespace("TargetType.FullName", node));
    }
    private static string[] EmptyGroupName = new string[] { ModelEditorGroupingHelper.UnspecifiedGroupName };
    public string[] GroupPathCalculatorByNamespace(string propertyName, IModelNode modelNode) {
        object propertyValue = ModelEditorGroupingHelper.Instance.GetPropertyValue(propertyName, modelNode);
        if(propertyValue != null) {
            string typeName = propertyValue.ToString();
            if(!string.IsNullOrEmpty(typeName)) {
                int lastPointIndex = typeName.LastIndexOf('.');
                if(lastPointIndex > 0) {
                    return new string[] {
                        typeName.Substring(0, lastPointIndex),
                        typeName.Substring(lastPointIndex + 1)
                    };
                }
                else {
                    return new string[] { typeName };
                }
            }
        }
        return EmptyGroupName;
    }
    // ...
}

VB.NET

Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.DC
Imports DevExpress.ExpressApp.Model
Imports DevExpress.ExpressApp.ModelEditor
Imports DevExpress.ExpressApp.Model.Core
Imports DevExpress.ExpressApp.Validation
' ...
Public NotInheritable Partial Class MySolutionModule
    Inherits ModuleBase
    Public Sub New()
        InitializeComponent()
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(GetType(IModelValidationRules), Function(node) GroupPathCalculatorByNamespace("TargetType.FullName", node))
    End Sub

    Private Shared EmptyGroupName As String() = New String() {ModelEditorGroupingHelper.UnspecifiedGroupName}
    Public Function GroupPathCalculatorByNamespace(propertyName As String, modelNode As IModelNode) As String()
        Dim propertyValue As Object = ModelEditorGroupingHelper.Instance.GetPropertyValue(propertyName, modelNode)
        If propertyValue IsNot Nothing Then
            Dim typeName As String = propertyValue.ToString()
            If Not String.IsNullOrEmpty(typeName) Then
                Dim lastPointIndex As Integer = typeName.LastIndexOf("."c)
                If lastPointIndex > 0 Then
                    Return New String() {typeName.Substring(0, lastPointIndex), typeName.Substring(lastPointIndex + 1)}
                Else
                    Return New String() {typeName}
                End If
            End If
        End If
        Return EmptyGroupName
    End Function
    ' ...
End Class

The following image demonstrates the grouped Validation | Rules nodes:

You can apply the same grouping mechanism to other model nodes. The following example demonstrates how to register the GroupPathCalculatorByNamespace mechanism for the IModelViews node in addition to IModelValidationRules.

File: MySolution.Module\Module.cs(.vb).

C#

using DevExpress.ExpressApp; 
using DevExpress.ExpressApp.DC;
using DevExpress.ExpressApp.Model;
using DevExpress.ExpressApp.ModelEditor; 
using DevExpress.ExpressApp.Model.Core;
// ...
public sealed partial class MySolutionModule : ModuleBase {
    public MySolutionModule() {
        InitializeComponent();
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(
            typeof(IModelValidationRules), 
            node => GroupPathCalculatorByNamespace("TargetType.FullName", node)
        );
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(
            typeof(IModelViews), 
            node => GroupPathCalculatorByNamespace("ModelClass.Name", node)
        );
    }
    // ...
}

VB.NET

Imports DevExpress.ExpressApp
Imports DevExpress.ExpressApp.DC
Imports DevExpress.ExpressApp.Model
Imports DevExpress.ExpressApp.ModelEditor
Imports DevExpress.ExpressApp.Model.Core
' ...
Public NotInheritable Partial Class MySolutionModule
    Inherits ModuleBase
    Public Sub New()
        InitializeComponent()
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(
            GetType(IModelValidationRules),
            Function(node) GroupPathCalculatorByNamespace("TargetType.FullName", node)
        )
        ModelEditorGroupingHelper.Instance.RegisterNodeGroupPathDelegate(
            GetType(IModelViews),
            Function(node) GroupPathCalculatorByNamespace("ModelClass.Name", node)
        )
    End Sub
    ' ...
End Class

The following image demonstrates the grouped Views nodes:

Note

XAF uses the same mechanism to group the Validation | Rules and Views nodes.

Inheritance

Object

ModelEditorGroupingHelper