Prevent Users from Deleting and Updating Administrative User and Role Objects

• Apr 12, 2024
• 3 minutes to read

This topic explains how to create Validation and Conditional Appearance Rules to prevent users from deleting and updating administrative user and role objects. These rules affect all users including administrative users.

This help topic uses the ApplicationUser class generated by the XAF Solution Wizard as well as the EF Core-based PermissionPolicyRole class. In applications based on XPO, use the PermissionPolicyRole class from the DevExpress.Persistent.BaseImpl.PermissionPolicy namespace.

Prevent Deletion of Administrative Users and Roles

1. Add the Validation Module to the platform-agnostic Module.

2. Open the Model Editor and navigate to the Application | Validation | Rules node. Right-click this node and add the following RuleCriteria that prevents deletion of the “Admin“ user and “Administrators“ role:

   Rule ID	TargetContextIDs	Criteria[1]	TargetType	CustomMessageTemplate
   PreventDeleteAdminUser	Delete	[UserName] != ‘Admin’	ApplicationUser (or a custom user type)	Cannot remove this user.
   PreventDeleteAdminRole	Delete	[Name] != ‘Administrators’	PermissionPolicyRole (or a custom role type)	Cannot remove this role.

   

   Alternatively, you can open the Model.DesignedDiffs.xafml file as an XML file and add the following elements:

   XML

   <?xml version="1.0" encoding="utf-8"?>
   <Application>
     <!-- ... -->
     <Validation>
       <Rules>
         <!-- ... -->
         <RuleCriteria 
           Id="PreventDeleteAdminUser" 
           TargetContextIDs="Delete" 
           Criteria="[UserName] != 'Admin'" 
           TargetType="MySolution.Module.BusinessObjects.ApplicationUser" 
           CustomMessageTemplate="Cannot remove this user." 
           IsNewNode="True" />
         <RuleCriteria 
           Id="PreventDeleteAdminRole" 
           TargetContextIDs="Delete" 
           Criteria="[Name] != 'Administrators'" 
           TargetType="DevExpress.Persistent.BaseImpl.EF.PermissionPolicy.PermissionPolicyRole" 
           CustomMessageTemplate="Cannot remove this role." 
           IsNewNode="True" />
       </Rules>
     </Validation>
   </Application>
   

The following image shows the result:

Prevent Update of Administrative Users and Roles

1. Add the Conditional Appearance Module to the platform-agnostic Module.

2. Open the Model Editor and navigate to the Application | BOModel | MySolution.Module.BusinessObjects | ApplicationUser | AppearanceRules node. Right-click this node and add the following rule that disables editors in the Detail View of the “Admin“ User:

   ID	Enabled	Context	Criteria[1]	Target Items
   DisableAdminUserEditors	False	DetailView	[UserName] == ‘Admin’	IsActive; Roles; UserName

   

   Alternatively, you can open the Model.DesignedDiffs.xafml file as an XML file and add the following element:

   XML

   <?xml version="1.0" encoding="utf-8"?>
   <Application>
     <!-- ... -->
     <BOModel>
       <!-- ... -->
       <Class Name="MySolution.Module.BusinessObjects.ApplicationUser">
         <AppearanceRules>
           <AppearanceRule 
             Id="DisableAdminUserEditors" 
             Enabled="False" 
             Context="DetailView" 
             Criteria="[UserName] == 'Admin'" 
             TargetItems="IsActive; Roles; UserName" 
             IsNewNode="True" />
         </AppearanceRules>
       </Class>
     </BOModel>
   </Application>
   

3. Open the Model Editor and navigate to the Application | BOModel | DevExpress.Persistent.BaseImpl.EF.PermissionPolicy | PermissionPolicyRole | AppearanceRules node. Right-click this node and add the following rule that disables editors in the Detail View of the “Administrators“ Role:

   ID	Enabled	Context	Criteria	Target Items
   DisableAdminRoleEditors	False	DetailView	[Name] == ‘Administrators’	Name; Users; IsAdministrative

   

   Alternatively, you can open the Model.DesignedDiffs.xafml file as an XML file and add the following element:

   XML

   <?xml version="1.0" encoding="utf-8"?>
   <Application>
     <!-- ... -->
     <BOModel>
       <!-- ... -->
       <Class Name="DevExpress.Persistent.BaseImpl.EF.PermissionPolicy.PermissionPolicyUser">
         <AppearanceRules>
           <AppearanceRule 
             Id="DisableAdminRoleEditors" 
             Enabled="False" 
             Context="DetailView" 
             TargetItems="Name; Users; IsAdministrative" 
             Criteria="[Name] == 'Administrators'" 
             IsNewNode="True" />
         </AppearanceRules>
       </Class>
     </BOModel>
   </Application>  
   

The following image shows the result:

Footnotes

1. Note that users should have permission to read the PermissionPolicyUser.UserName and PermissionPolicyRole.Name properties. Otherwise, their values are replaced with the “*******“ placeholder and no object matches the specified criteria. Grant permission to read the UserName and Name properties or use Oid/Id instead in criteria (all users have permission to read this property).