PermissionSettingHelper.AddObjectPermissionFromLambda<T>(IPermissionPolicyRole, String, Expression<Func<T, Boolean>>, Nullable<SecurityPermissionState>) Method

Finds the first type permission for the specified type in the role and adds the object permission to it. If the appropriate type permission is not found, this method creates it.

Namespace: DevExpress.ExpressApp.Security

Assembly: DevExpress.ExpressApp.Security.v25.1.dll

NuGet Package: DevExpress.ExpressApp.Security

Declaration

C#

public static IPermissionPolicyObjectPermissionsObject AddObjectPermissionFromLambda<T>(
    this IPermissionPolicyRole role,
    string operations,
    Expression<Func<T, bool>> lambda,
    SecurityPermissionState? state
)
    where T : class

VB.NET

<ExtensionAttribute>
Public Shared Function AddObjectPermissionFromLambda(Of T As Class)(
    role As IPermissionPolicyRole,
    operations As String,
    lambda As Expression(Of Func(Of T, Boolean)),
    state As SecurityPermissionState?
) As IPermissionPolicyObjectPermissionsObject

Parameters

Name	Type	Description
role	IPermissionPolicyRole	The target role for a new object permission.
operations	String	The semicolon-separated list of security operations. The static SecurityOperations class defines operation names and their delimiter.
lambda	Expression<Func<T, Boolean>>	The lambda expression that specifies the target object(s).
state	Nullable<SecurityPermissionState>	A SecurityPermissionState enumeration value that specifies if access is granted or denied.

Type Parameters

Name	Description
T	This method finds the type permission for this type in the role.

Returns

Type	Description
DevExpress.Persistent.Base.IPermissionPolicyObjectPermissionsObject	The added object permission.

Remarks

The following example demonstrates how to use this method in UpdateDatabaseAfterUpdateSchema() (MySolution.Module\DatabaseUpdater\Updater.cs(.vb)):

C#

using DevExpress.Data.Filtering;
using DevExpress.ExpressApp.Security;
using DevExpress.ExpressApp.SystemModule;
using DevExpress.ExpressApp.Updating;
using DevExpress.Persistent.Base;
using DevExpress.Persistent.BaseImpl.PermissionPolicy;
// ...
public class Updater : ModuleUpdater {
    // ...
    public override void UpdateDatabaseAfterUpdateSchema() {
        base.UpdateDatabaseAfterUpdateSchema();
        PermissionPolicyRole defaultRole = ObjectSpace.FirstOrDefault<PermissionPolicyRole>(role => role.Name == "Default");
        if(defaultRole == null) {
            defaultRole = ObjectSpace.CreateObject<PermissionPolicyRole>();
            defaultRole.AddObjectPermissionFromLambda<PermissionPolicyUser>(
                SecurityOperations.Read, 
                u => u.Oid == (Guid)CurrentUserIdOperator.CurrentUserId(),
                SecurityPermissionState.Allow
            );
            // ...
        }
        // ...
    }
}

VB.NET

Imports DevExpress.Data.Filtering
Imports DevExpress.ExpressApp.Security
Imports DevExpress.ExpressApp.SystemModule
Imports DevExpress.ExpressApp.Updating
Imports DevExpress.Persistent.Base
Imports DevExpress.Persistent.BaseImpl.PermissionPolicy
' ...
Public Class Updater
    Inherits ModuleUpdater
    ' ...
    Public Overrides Sub UpdateDatabaseAfterUpdateSchema()
        MyBase.UpdateDatabaseAfterUpdateSchema()
        Dim defaultRole As PermissionPolicyRole = 
            ObjectSpace.FirstOrDefault(Function(role as PermissionPolicyRole) role.Name = "Default")
        If defaultRole Is Nothing Then
            defaultRole = ObjectSpace.CreateObject(Of PermissionPolicyRole)()
            defaultRole.AddObjectPermissionFromLambda(Of PermissionPolicyUser)(
                SecurityOperations.Read, 
                Function(u As PermissionPolicyUser) u.Oid = CType(CurrentUserIdOperator.CurrentUserId(), Guid), 
                SecurityPermissionState.Allow
            )
            ' ...
        End If
        ' ...
    End Sub
End Class

Note

Alternatively, you can use the AddObjectPermission<T>(IPermissionPolicyRole, String, String, Nullable<SecurityPermissionState>) method, which takes a criteria expression instead of a lambda expression.