Manage Button Visibility in a Blazor Lookup Property Editor

• 3 minutes to read

XAF manages the visibility of New and Edit buttons inside an ASP.NET Core Blazor Lookup Property Editor according to Security System permissions, business object settings, and Action parameters.

Lookup Property Editor in a Detail View

Lookup Property Editor in a List View with in-place editing enabled

Call the following LookupPropertyEditor methods to hide or display these buttons:

HideNewButton

Hides the New button.

HideEditButton

Hides the Edit button.

ResetNewButtonVisibility

Displays the hidden New button.

ResetEditButtonVisibility

Displays the hidden Edit button.

Note

The Edit button acts as a clickable link. Use Ctrl + click or click the middle mouse button to open the referenced object in a new browser tab. To disable this behavior, add a Controller to your application, as described in the following topic: Hide Hyperlinks in Lookup Controls.

In a Detail View

When LookupEditorMode is set to AllItems or Auto, and View mode is enabled, XAF displays the Lookup Property Editor as a Text Box with an Edit button. When the user clicks the button, XAF changes the editor to a ComboBox.

Each mode uses a different collection to maintain editor buttons: the ViewModeButtons collection in View mode, the Buttons collection in Edit mode. Check which collection is available to determine the current mode.

Call HideNewButton and HideEditButton in the Controller’s OnActivated method to hide the New and Edit buttons. Note that XAF displays referenced objects as clickable links. Disable the ShowLink property to display referenced objects as plain text.

MySolution.Blazor.Server\Controllers\LookupActionVisibilityController.cs

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Blazor.Editors;
using DevExpress.ExpressApp.Blazor.Utils;
// ...
public class LookupActionVisibilityController : ViewController {
    protected override void OnActivated() {
        base.OnActivated();
        View.CustomizeViewItemControl<LookupPropertyEditor>(this, e => {
            // Hide New and Edit buttons in Edit mode
            if (e.Buttons != null) {
                e.HideNewButton();
                e.HideEditButton();
            }
            // Show referenced objects as text in View mode
            else {
                e.ShowLink = false;
            }
        });
    }
}

These changes apply to Detail Views and to List Views when in-place editing is enabled. To apply the changes for a particular View, use the CustomizeViewItemControl<T>(View, Controller, Action<T>) method.

Manage Button Visibility in Actions

The following code snippet uses Actions to manage lookup editor button visibility:

MySolution.Blazor.Server\Controllers\LookupActionVisibilityController.cs

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.ExpressApp.Blazor.Editors;
using DevExpress.Persistent.Base;
// ...
public class LookupActionVisibilityController : ViewController<DetailView> {
    public LookupActionVisibilityController() {
        SimpleAction hideNewAction = new SimpleAction(this, "Hide New", PredefinedCategory.Edit);
        SimpleAction hideEditAction = new SimpleAction(this, "Hide Edit", PredefinedCategory.Edit);
        SimpleAction resetNewAction = new SimpleAction(this, "Reset New", PredefinedCategory.Edit);
        SimpleAction resetEditAction = new SimpleAction(this, "Reset Edit", PredefinedCategory.Edit);
        hideNewAction.Execute += (s, e) => {
            View.CustomizeViewItemControl<LookupPropertyEditor>(this, e => {
                e.HideNewButton();
            });
        };
        hideEditAction.Execute += (s, e) => {
            View.CustomizeViewItemControl<LookupPropertyEditor>(this, e => {
                e.HideEditButton();
            });
        };
        resetNewAction.Execute += (s, e) => {
            View.CustomizeViewItemControl<LookupPropertyEditor>(this, e => {
                e.ResetNewButtonVisibility();
            });
        };
        resetEditAction.Execute += (s, e) => {
            View.CustomizeViewItemControl<LookupPropertyEditor>(this, e => {
                e.ResetEditButtonVisibility();
            });
        };
    }
}