WebPropertyEditor Class

The base class for Property Editors that use controls inherited from a System.Web.UI.WebControls.WebControl.

Namespace: DevExpress.ExpressApp.Web.Editors

Assembly: DevExpress.ExpressApp.Web.v22.1.dll

Declaration

C#

public abstract class WebPropertyEditor :
    PropertyEditor,
    ISupportViewEditMode,
    IAppearanceFormat,
    IAppearanceBase,
    ISupportToolTip,
    ISupportImmediatePostData

VB.NET

Public MustInherit Class WebPropertyEditor
    Inherits PropertyEditor
    Implements ISupportViewEditMode,
               IAppearanceFormat,
               IAppearanceBase,
               ISupportToolTip,
               ISupportImmediatePostData

Related API Members

The following members return WebPropertyEditor objects:

• ComplexWebListEditor.FindPropertyEditor(IModelMemberViewItem, ViewEditMode)
• ComplexWebListEditor.FindPropertyEditor(String, ViewEditMode)

Remarks

Inherit the WebPropertyEditor class to implement a Property Editor using third-party or custom ASP.NET Web Forms controls. If you use DevExpress controls inherited from ASPxEditBase, use the ASPxPropertyEditor class instead.

In ASP.NET Web Forms XAF applications, Detail Views can be displayed in two modes - view (read only) and edit (editable). To support these modes, the WebPropertyEditor class introduces the following properties:

Member	Description
ViewEditMode	Specifies the current display mode of the Property Editor’s control.
Editor	Returns the Property Editor’s control used in edit mode.
InplaceViewModeEditor	Returns the Property Editor’s control used in view mode.

The WebPropertyEditor class implements the IAppearanceFormat interface to support conditional appearance rules.

Inherit WebPropertyEditor

Specify and Setup the Edit Mode Control

• The CreateEditModeControlCore abstract method:

  • Instantiates the control to be used in the edit mode.
  • Performs the initial setup of the control.

  • Subscribes to control’s events that occur on a control value change. Each event handler calls the EditValueChangedHandler method. The EditValueChangedHandler method is the general-purpose handler for value-changed events. This method raises the ControlValueChanged event and calls the WriteValue() method.

    C#

    protected override WebControl CreateEditModeControlCore() {
        ASPxSpinEdit control = new ASPxSpinEdit();
        // Setup  the control:
        control.ValueChanged += EditValueChangedHandler;
        return control;
    }
    

    VB.NET

    Protected Overrides Function CreateEditModeControlCore() As WebControl
        Dim control As New ASPxSpinEdit()
        ' Setup  the control:
        AddHandler control.ValueChanged, AddressOf EditValueChangedHandler
        Return control
    End Function
    

• The ReadEditModeValueCore abstract method passes the PropertyValue to the property of the Editor control specifying the displayed content (e.g., Text, Value, etc.).

  C#

  protected override void ReadEditModeValueCore() {
      ((ASPxSpinEdit)Editor).Value = PropertyValue;
  }
  

  VB.NET

  Protected Overrides Sub ReadEditModeValueCore()
      CType(Editor, ASPxSpinEdit).Value = PropertyValue
  End Sub
  

• The GetControlValueCore abstract method returns the value specified by the WebPropertyEditor.Editor control used in the edit mode.

  C#

  protected override object GetControlValueCore() {
      return ((ASPxSpinEdit)Editor).Value;
  }
  

  VB.NET

  Protected Overrides Function GetControlValueCore() As Object
      Return (CType(Editor, ASPxSpinEdit)).Value
  End Function
  

Customize the View Mode Control (Optionally)

The System.Web.UI.WebControls.Label control is used in the view mode by default. Override these methods to customize the label’s string representation or to use another control.

• Override The GetPropertyDisplayValue method to customize the string representation of the property value.

  C#

  protected override string GetPropertyDisplayValue() {
      string result = base.GetPropertyDisplayValue();
      if (string.IsNullOrEmpty(result)) result = "none";
      return result;
  }
  

  VB.NET

  Protected Overrides Function GetPropertyDisplayValue() As String
      Dim result As String = MyBase.GetPropertyDisplayValue()
      If String.IsNullOrEmpty(result) Then
          result = "none"
      End If
      Return result
  End Function
  

• The CreateViewModeControlCore method instantiates and initializes the control used in the view mode.

  C#

  protected override WebControl CreateViewModeControlCore() {
      Label control = new Label();
      // Setup 'control' here.
      return control;
  }
  

  VB.NET

  Protected Overrides Function CreateViewModeControlCore() As WebControl
      Dim control As New Label()
      ' Setup 'control' here.
      Return control
  End Function
  

• The ReadViewModeValueCore method passes the PropertyValue value to the property of the InplaceViewModeEditor control specifying the displayed content (e.g., Text, Value, etc.).

  C#

  protected override void ReadViewModeValueCore() {
      ((Label)InplaceViewModeEditor).Value = PropertyValue;
  }
  

  VB.NET

  Protected Overrides Sub ReadViewModeValueCore()
      CType(InplaceViewModeEditor, Label).Value = PropertyValue
  End Sub
  

Additional Customizations

• The SetupControl method instantiates and initializes the control for which the customization code is provided. This method is called when the control is initialized (the Init event occurs).

  C#

  protected override void SetupControl(WebControl control) {
      base.SetupControl(control);
      if(ViewEditMode == ViewEditMode.Edit) {
          ASPxSpinEdit spinEdit = (ASPxSpinEdit)control;
          spinEdit.Width = Unit.Pixel(100);
      }
  }
  

  VB.NET

  Protected Overrides Sub SetupControl(ByVal control As WebControl)
      MyBase.SetupControl(control)
      If ViewEditMode = ViewEditMode.Edit Then 
          Dim spinEdit As ASPxSpinEdit = CType(control, ASPxSpinEdit)
          spinEdit.Width = Unit.Pixel(100)
      End If 
  End Sub
  

• The BreakLinksToControl(Boolean) method disposes manually allocated resources and unsubscribes from control events.

  C#

  public override void BreakLinksToControl(bool unwireEventsOnly) {
      if(Editor != null) {
          ((ASPxSpinEdit)Editor).ValueChanged -= EditValueChangedHandler;
      }
      base.BreakLinksToControl(unwireEventsOnly);
  }
  

  VB.NET

  Public Overrides Sub BreakLinksToControl(ByVal unwireEventsOnly As Boolean)
      If Editor IsNot Nothing Then
          RemoveHandler CType(Editor, ASPxSpinEdit).ValueChanged, AddressOf EditValueChangedHandler
      End If
      MyBase.BreakLinksToControl(unwireEventsOnly)
  End Sub
  

• The SetProcessValueChangedScript method registers a script passed to this method parameter to support the IModelOptionsWeb.ConfirmUnsavedChanges mode. The script is executed on the client side after the property value is changed by user. If you use any DevExpress web control, pass the script to the [EditClientSideEvents.ValueChanged]ValueChanged client-side event of the control’s ClientSideEvents object.

  C#

  protected override void SetProcessValueChangedScript(string script) {
      if (Editor != null) {
          ClientSideEventsHelper.AssignClientHandlerSafe((ASPxSpinEdit)Editor, "ValueChanged", script, Guid.NewGuid().ToString());
      }
  }
  

  VB.NET

  Protected Overrides Sub SetProcessValueChangedScript(script As String)
      If Editor IsNot Nothing Then
          ClientSideEventsHelper.AssignClientHandlerSafe(CType(Editor, ASPxSpinEdit), "ValueChanged", script, Guid.NewGuid().ToString())
      End If
  End Sub
  

  If you use a custom third-party control, you should implement a code that provides the script execution when a user updates the editor value.

• The SetImmediatePostDataScript method registers a script passed to this method parameter to support the ImmediatePostDataAttribute functionality (it is called only when ImmediatePostData is true). The script should be executed on the client side after the property value is changed by a user. If you use any DevExpress web control, pass the script to the ValueChanged client-side event of the control’s ClientSideEvents object.

  C#

  protected override void SetImmediatePostDataScript(string script) {
      ClientSideEventsHelper.AssignClientHandlerSafe((ASPxSpinEdit)Editor, "ValueChanged", script, Guid.NewGuid().ToString());
  }
  

  VB.NET

  Protected Overrides Sub SetImmediatePostDataScript(ByVal script As String)
          ClientSideEventsHelper.AssignClientHandlerSafe(CType(Editor, ASPxSpinEdit), "ValueChanged", script, Guid.NewGuid().ToString())
  End Sub
  

  If you use a custom third-party control, you should implement a code that provides the script execution at the moment a user updates the editor value.

• The ApplyReadOnly method assigns the AllowEdit value to the Enabled property of the Editor control used in the edit mode. You can apply extra customizations in this method.

  C#

  protected override void ApplyReadOnly() {
      base.ApplyReadOnly();
      if (!AllowEdit) {
          Editor.ToolTip = "You cannot change this value";
      }
      else {
          Editor.ToolTip = string.Empty;
      }
  }
  

  VB.NET

  Protected Overrides Sub ApplyReadOnly()
      MyBase.ApplyReadOnly()
      If Not AllowEdit.ResultValue Then
          Editor.ToolTip = "You cannot change this value"
      Else
          Editor.ToolTip = String.Empty
      End If
  End Sub
  

Important

• A custom Property Editor that derives from the WebPropertyEditor should not throw exceptions. Exceptions thrown by such a Property Editor interrupt request processing. As a result, the application crashes.
• The WebPropertyEditor‘s descendant should be public.
• The WebPropertyEditor sets the ID value for the Editor and InplaceViewModeEditor controls. If you use a custom complex control with the inner controls hierarchy, set the ID for each inner control. For details, refer to the How to create controls dynamically article.

To see an example of a Property Editor derived from the WebPropertyEditor class, refer to the How to: Implement a Property Editor Based on Custom Controls (ASP.NET Web Forms).

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the WebPropertyEditor class.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XAF_how-to-highlight-the-focused-editor-in-detailview-e2106/CS/WinWebSolution.Module.Web/WebHighlightFocusedLayoutItemDetailViewController.cs#L17

base.OnActivated();
foreach (WebPropertyEditor item in View.GetItems<WebPropertyEditor>()) {
    if (item.Editor != null) {

XAF_how-to-enable-in-place-editing-in-the-aspnet-tree-list-view-aspxtreelisteditor-e3570/CS/WebExample.Module.Web/TreeListInlineEditController.cs#L25

if (column is TreeListDataColumn && ((TreeListDataColumn)column).EditCellTemplate != null) {
    WebPropertyEditor propertyEditor = ((EditModeDataItemTemplate)((TreeListDataColumn)column).EditCellTemplate).PropertyEditor;
    propertyEditor.ControlCreated += new EventHandler<EventArgs>(propertyEditor_ControlCreated);

VB.NET

XAF_how-to-highlight-the-focused-editor-in-detailview-e2106/VB/WinWebSolution.Module.Web/WebHighlightFocusedLayoutItemDetailViewController.vb#L19

MyBase.OnActivated()
For Each item As WebPropertyEditor In View.GetItems(Of WebPropertyEditor)()
    If item.Editor IsNot Nothing Then

XAF_how-to-enable-in-place-editing-in-the-aspnet-tree-list-view-aspxtreelisteditor-e3570/VB/WebExample.Module.Web/TreeListInlineEditController.vb#L27

If TypeOf column Is TreeListDataColumn AndAlso CType(column, TreeListDataColumn).EditCellTemplate IsNot Nothing Then
    Dim propertyEditor As WebPropertyEditor = CType(CType(column, TreeListDataColumn).EditCellTemplate, EditModeDataItemTemplate).PropertyEditor
    AddHandler propertyEditor.ControlCreated, AddressOf propertyEditor_ControlCreated

Implements

IAppearanceEnabled

IAppearanceVisibility

INotifyAppearanceVisibilityChanged

IAppearanceFormat

Inheritance

Object

ViewItem

PropertyEditor

WebPropertyEditor

ASPxPropertyEditor

WebMapsPropertyEditor