NullReferenceException in SetProperty or GetProperty when adding row from Telerik grid

[Mikael-Pothier]

Hello,

I'm currently updating csla for my blazor project to the latest version(from 5.4) and it went well for most of the update. But when I started testing the site I couldn't add or modify any grid. The grid we are using are from Telerik. When I'm trying to add a row in a grid I have this error in Csla in the SetProperty(it can also be in the GetProperty)

And I check the value and it is false and the property seems fine too

Unfortunately, I don't know precisely when the error occurred since it is in the code behind of Telerik and I cannot access it.

I know it might be a problem from Telerik but I wasn't sure where to start so sorry if I'm not at the right place And thank you for your help in advance.

[TheCakeMonster]

Have you got some basic unit tests to exercise your business objects in the same way as within your UI, but disassociated from it? That might be a way to split the problem in half, and escape the potential for it being a problem with the Telerik UI components.

I wonder if it's to do with the way you are creating the objects in the first place. Are you getting the original objects via an injected instance of IDataPortal? Your error reminds me a bit of the type of errors you see when an object was created by newing it up, rather than it having been created by the DataPortal. That might seem obvious, but it's very easy to get wrong.

Do you have any rules associated with the property that is throwing the exception?

There has been some discussion elsewhere about the creation of new child objects in collections. Have a read of issue #3141, which I think resulted in a fix, but I wasn't following closely.

[Mikael-Pothier]

Yes, we have some basic test which add a parent and then add a child and everything works properly. The property doesn't have any rules and I tried what was in #3141 and it gives the same error. I added the override method with the part that set the application (see image below) but it doesn't go into this function when I debug my code.

We are creating the dataportal via DI in a razor page. Here is the inject of the dataportal and below the call that fetch my parent object which contain my list of child

I think you might be onto something with "creating by newing it up" because I think Telerik create a copy of the object since they have a cancel button that gets back the original object and they probably create it via the constructor.

[Mikael-Pothier]

With further test I found out that the ApplicationContext is Null when it goes into the SetProperty.

Here is the stack trace of the error
at Csla.Core.BusinessBase.VerifyAuthorizationCache()
at Csla.Core.BusinessBase.CanWriteProperty(IPropertyInfo property)
at Csla.Core.BusinessBase.CanWriteProperty(IPropertyInfo property, Boolean throwOnFalse)
at Csla.Core.BusinessBase.SetProperty[P](PropertyInfo`1 propertyInfo, P newValue, NoAccessBehavior noAccess)
at Primaco.Library.Versements.set_EdiCash(Boolean value) in C:\Users\potml.primdev\Documents\Source\Repos\Pforce\Primaco.Library\Entities\Versements.cs:line 38

If I go in the VerifyAuthorizationCache it does use the applicationContext like this

[MarkOverstreet]

Just an option for you, DevExpress has worked great for us with CSLA and blazor including their grid.

[fundez]

We also own devexpress. the only issue is currently devexpress grids doesn't support batch editing. You need to click an edit button on each row to start editing. Though they are planning to enable this feature in December.

[fundez]

We also own devexpress. the only issue is currently devexpress grids doesn't support batch editing. You need to click an edit button on each row to start editing. Though they are planning to enable this feature in December.

[rockfordlhotka]

In terms of workarounds, I don't know, but can provide info around the way CSLA works.

CSLA creates domain instances like this:

1. var newObject = Activator.Create(businessType)
2. If newObject implements IUseApplicationContext, set ApplicationContext
3. Done

I'm guessing that the datagrid control is doing step 1 (???)

Obviously it can't know to do step 2, and so you need to handle some "object created" or "row created" event in the datagrid to do step 2.

Ideally the datagrid would allow you to create the instance of the object for each row, in which case you could use the CSLA helper method to create the BO instance, but failing that you'll need to interact with IUseApplicationContext as a separate step.

[fundez]

Thanks Rocky, I ended up going back to CSLA 5 while I wait for Telerik or devpress to release updates. Luckily v5 supports the Idataportal so I don't need to remove dataportal calls so it will make upgrading to 7 later much easier.