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Wednesday, January 21, 2015

Simplifying integration of custom controls bound to data from XAF application database - YOUR FEEDBACK IS NEEDED


We are researching options to make it easier for our users to achieve the subject in the next version. One of the popular scenarios we were aware of from our users was integration of custom controls, often created in Visual Studio using the standard WinForms or ASP.NET WebForms approaches, and primarily designed for presenting data from the XAF application database in some very custom manner so that built-in XAF Property Editors  or List Editors were not good for this. For instance, you might want to show a list of records in a fancy grid with cards, image gallery or other controls or modes not integrated by default.

Current solutions and problems

XAF is very extensible framework and offers many ways of integrating custom or third party controls. We noticed that while doing so, feeding these custom controls with data from the application database was often a challenge for our users. This binding is done automatically for built-in forms and data editors, but requires writing some code that will read data via the IObjectSpace.GetObjects<T> method (to respect data security filters) and also listen to the IObjectSpace.Reloaded and other events to handle data updates. Finally, designing a data bound user control in Visual Studio often implies a direct connection to the database or using specialized data sources (e.g., to generate a list of grid columns or pivot fields), which do this for you. The latter forces you to think about obtaining an application connection string at design time, while this dynamic part is changed later in the most cases. Add to this different approaches for Entity Framework and XPO and you will get the whole picture.

New solutions (not yet built-in!)

Briefly, we decided to simplify this scenario. Here are two videos that shows one possible option:



How it works?

In short, the proposed flow is as follows:

Beware of Windows update KB3025390 as it breaks EasyTest functionality in Internet Explorer 11

We were lucky enough to come across this issue when one day, almost all our internal functional tests (we use our in-house EasyTest engine) for XAF Web UI failed due to the following error:

    Type:       UnauthorizedAccessException
    Message:    Access is denied.

    Data:       0 entries
    Stack trace:

   at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo)
   at System.Runtime.InteropServices.Marshal.ThrowExceptionForHR(Int32 errorCode)
   at System.Runtime.InteropServices.CustomMarshalers.ExpandoViewOfDispatchEx.DispExInvoke(String pstrMemberName, Int32 MemberDispID, Int32 Flags, Binder pBinder, Object[] aArgs, ParameterModifier[] aModifiers, CultureInfo pCultureInfo, String[] astrNamedParameters)
   at System.Runtime.InteropServices.CustomMarshalers.DispatchExMethodInfo.Invoke(Object pObj, BindingFlags invokeAttr, Binder pBinder, Object[] aParameters, CultureInfo pCulture)
   at System.Runtime.InteropServices.CustomMarshalers.DispatchExPropertyInfo.GetValue(Object pObj, BindingFlags invokeAttr, Binder binder, Object[] aIndex, CultureInfo culture)
   at System.Reflection.PropertyInfo.GetValue(Object obj, Object[] index)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.<>c__DisplayClasse.<GetIReflectTestControlCore>b__9(Object obj)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.ExecuteTimeoutFunction(Int32 timeoutMilliseconds, Int32 sleepTime, Predicate`1 predicate, Func`1 onTimeoutPredicate)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.GetIReflectTestControlCore(String testControlsName, IHTMLDocument2 doc)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.GetIReflectTestControl(String testControlsName, IHTMLDocument2 doc)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.UpdateTestControls()
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebCommandAdapter.WaitForBrowserResponse(Boolean waitPostback, Boolean isSecondCall)
   at DevExpress.ExpressApp.EasyTest.WebAdapter.WebAdapter.CreateCommandAdapter()
   at DevExpress.EasyTest.Framework.TestExecutor.CreateCommandAdapterCore(IApplicationAdapter adapter)
   at DevExpress.EasyTest.Framework.TestExecutor.ExecuteCommands(IApplicationAdapter adapter, String& applicationName)
    InnerException is null

After several hours of researching and googling, we found out the Installation of KB3025390 breaks out-of-process JavaScript execution in IE11 ticket on MS Connect
as well as possible workarounds at

Thursday, January 8, 2015

Model.XAFML and storing XAF application UI settings in the database

As we are improving our newest "Persisting UI settings in the database" feature (quickly learn more about it from this video or blog), I wanted to pay your attention to the ModelDifferenceDbStore - Always take into account the latest changes made to the Model.XAFML file at design time ticket I created based on the users feedback. Let me quote myself from that thread:

By default, starting with v14.2, all new XAF WinForms projects will store administrative (Model.XAFML) and user differences in the database tables (ModelDifference and ModelDifferenceAspect). 

This built-in option stems from the How to: Store Model Differences in Database example we had in the past.
This new behavior is plugged-in if the Security System is enabled in the Solution Wizard and is technically done by subscribing to the CreateCustomModelDifferenceStore and CreateCustomUserModelDifferenceStore events within YourSolutionName.Module.Win/Module.xx file. Refer to the eXpressApp Framework > Task-Based Help > How to: Store the Application Model Differences in the Database article for more details.

Problem description
As of v14.2.3, the contents of the Model.XAFML file are once read during the first application run and are stored in the database. Thus, any subsequent changes to the Model.XAFML file during development will not be re-read into the database or ignored. This feature request is for improving the developers' experience when this feature is in use.

Current solutions
Take special note that to start reading subsequent customizations from the Model.XAFML file at every application run as it was in the past, you will need to backup and then drop the existing ModelDifference and ModelDifferenceAspect tables in  your test database on your development machine.