Data change checking features in DotNetNuke pages.

I’ve used  data change checking features  described by Eric Woodruff in my ASP.NET application. When I converted the ASP.NET application to DotNetNuke, I still needed to have the same functionality.


Unfortunately .Net doesn’t allow multiple inheritanse,  so I had to re-factor EWSoftware.Web.BasePage.


I created an interface IDataChangeChecking, that described the public methods, relevant to data change checking:
//described in http://www.codeproject.com/aspnet/EWSWebPt2.asp
string
[] BypassPromptIds
bool CheckForDataChanges
bool Dirty
string[] SkipDataCheckIds
StateBag ControlViewState
//expose protected ViewState


and created public class DataChangeCheckingImpl with methods extracted from original BasePage






{
// Methods
public DataChangeCheckingImpl(Control owner);
public static void BypassChangesNotSavedPrompt(Control container, string ClientID);
public static void BypassChangesNotSavedPromptIDs_Add(Control container, string[] ClientIDs);
public void OnInit(EventArgs e);
public void OnPreRender(EventArgs e);
public static void SetCheckForDataChanges(Control container, bool value);
public static bool SetPageDirty(Control container, bool Value);
public static void SkipDataChangesCheckIDs_Add(Control container, string[] ClientIDs);

// Properties
public string[] BypassPromptIds { get; set; }
public bool CheckForDataChanges { get; set; }
public string ConfirmLeaveMessage { get; set; }
public bool Dirty { get; set; }
private HttpRequest Request { get; }
public string[] SkipDataCheckIds { get; set; }
public StateBag ViewState { get; }

// Fields
private bool bIsDirty;
private Control m_ctlOwner;
private IDataChangeChecking m_IDataChangeChecking;
}


Finally I’ve created DataChangeCheckingDefaultPage class, derived from DotNetNuke.Framework.CDefault and implementing IDataChangeChecking interface.


Additionaly OnInit event handler created DataChangeCheckingImpl object and methods
DataChangeCheckingImpl.OnInit and OnPreRender are called from the corresponding DataChangeCheckingDefaultPage event handlers.

Now I can configure data editing DotNetNuke modules, that user will see warning if he/she try to exit without saving data.