Blazor and CSLA Validator

[mikeclimbs23]

Hello,

I have a blazor server app using CSLA 5.5 and NetCore 5. I'm using devexpress blazor controls and have a weird issue. A combo box functions normally when placed on the page, but if I place the combobox in a component I get the error below when changing data. I only get this error if a CSLA validator is on my page. If I remove the CSLA validator the error goes away. My guess is the validator is looking for a property I'm not exposing in the component.

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.ArgumentException: Model does not implement required interface ICheckRules
   at Csla.Blazor.EditContextCslaExtensions.ValidateField(EditContext editContext, ValidationMessageStore messages, FieldIdentifier& fieldIdentifier)
   at Csla.Blazor.EditContextCslaExtensions.<>c__DisplayClass0_0.<AddCslaValidation>b__1(Object sender, FieldChangedEventArgs eventArgs)
   at Microsoft.AspNetCore.Components.Forms.EditContext.NotifyFieldChanged(FieldIdentifier& fieldIdentifier)
   at DevExpress.Blazor.Internal.DxEditorBase`2.OnValueChangedInternal()
   at DevExpress.Blazor.ComboBox.Internal.ComboBoxState`2.<>c__DisplayClass38_0.<set_ValueChanged>b__0(TData item)
   at DevExpress.Blazor.Internal.Rx.EmitterObserver`1.OnNext(T value)
   at DevExpress.Blazor.Internal.Rx.ObservableBase`1.NotifySubscriber(T& data, IObserver`1& observersSnapshot)
   at DevExpress.Blazor.Internal.Rx.ObservableStrategy`3.NotifySubscribers(T data)
   at DevExpress.Blazor.Internal.Grid.DataGridSelectionService`1.SetRowSelectedCore(T dataItem, Boolean value, DataGridSelectionMode mode, Boolean raiseChangedEvent)
   at DevExpress.Blazor.Internal.Grid.DataGridSelectionService`1.SetRowSelected(T dataItem, Boolean value, DataGridSelectionMode mode)
   at DevExpress.Blazor.Internal.Grid.DataGridDataItemSelectionState`1.<>c__DisplayClass3_0.<.ctor>b__2(Boolean selected)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at DevExpress.Blazor.Internal.Rx.ActionObserver`2.<>c.<.cctor>b__11_0(T v, TDelegate d)
   at DevExpress.Blazor.Internal.Rx.ActionObserver`2.DispatchNewValue(T& value)
   at DevExpress.Blazor.Internal.Rx.ObserverStrategy`1.OnNext(T value)
   at DevExpress.Blazor.Internal.Rx.ObservableBase`1.NotifySubscriber(T& data, IObserver`1& observersSnapshot)
   at DevExpress.Blazor.Internal.Rx.ObservableStrategy`3.NotifySubscribers(T data)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Delegate.DynamicInvokeImpl(Object[] args)
   at DevExpress.Blazor.Internal.Rx.ActionObserver`2.<>c.<.cctor>b__11_0(T v, TDelegate d)
   at DevExpress.Blazor.Internal.Rx.ActionObserver`2.DispatchNewValue(T& value)
   at DevExpress.Blazor.Internal.Rx.ObserverStrategy`1.OnNext(T value)
   at DevExpress.Blazor.Internal.ComboBoxDataRow`1.OnSingleSelectedRowClick(MouseEventArgs args)
   at DevExpress.Blazor.Internal.ListBoxDataRowBase`1.OnClick(MouseEventArgs args)
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

[rockfordlhotka]

Are you following the coding pattern from the ProjectTracker sample and/or my CSLA Blazor book when creating the component?

Can you share your component code?

[mikeclimbs23]

CO_StatesBase.zip

Within the page, here is the code using the component. <EzComboBox @bind-BindingValue="@vm.Model.Status">

The component code is below I also attached my business object. The component is bound to the status field.

Thanks,

Mike

@using System.Linq.Expressions
<DxComboBox TextFieldName="@nameof(StatusField.StatusName)"
            ValueFieldName="@nameof(StatusField.StatusLetter)"
            DropDownWidthMode="DropDownWidthMode.ContentWidth"
            CssClass="cmbStatus cmbStatusWidth"
            ValueExpression="@(() => BindingValue )"
            ValueChanged="@BindingValueChanged"
            Data="StatusTypes.Statuses"
            Value="@BindingValue">
</DxComboBox>

@code { private string _value;
    [Parameter]
    public string BindingValue
    {
        get =>
_value;
        set
        {
            if (_value == value) return;
            _value = value;
            BindingValueChanged.InvokeAsync(value);
        }
    }

    [Parameter]
    public EventCallback<string>
        BindingValueChanged
    { get; set; }

    public class StatusField
    {
        public string StatusName { get; set; }
        public string StatusLetter { get; set; }
    }

    public static class StatusTypes
    {
        private static readonly Lazy<List<StatusField>> statuses = new Lazy<List<StatusField>>(() =>
        {
            return new List<StatusField>()
                        {
                    new StatusField() {StatusName = "Active", StatusLetter = "A"},
                    new StatusField() {StatusName = "Inactive", StatusLetter = "I"},
                    new StatusField() {StatusName = "Xiscontinued", StatusLetter = "D"},
                  };
        });
        public static List<StatusField> Statuses { get { return statuses.Value; } }

    }

My object isn't an exact match to the example, but I think it's close. I have the code split across 2 units so I attached them both.

Thanks

Mike

[rockfordlhotka]

The thing is, the CSLA validation (and other features) require access to a Csla.Blazor.IPropertyInfo that comes in via a parameter.

https://github.com/MarimerLLC/csla/blob/main/Samples/ProjectTracker/ProjectTracker.Ui.Blazor/Shared/TextInput.razor

If you want access to the CSLA helpers and behaviors in your component you'll need that property info instance, through which you gain access to its Value and other properties.

[mikeclimbs23]

After lots of playing I confirmed the cslavalidator gets upset when it can't resolve the bind-Value of a control. If I place a devexpress dxComboBox directly on my page and set bind-Value to a string variable I get the same error pointing at IcheckRules.

Is it possible to tell the validator to skip certain fields?

Mike

[mikeclimbs23]

I should add the error only occurs if I change the field that's not bound to a csla object. It doesn't happen on load or save.

[mikeclimbs23]

Everyday I get a little closer. I put a stop in editcontext on fieldnamechanged. e.FieldIdentifier.FieldName is returning the variable name I'm bound to "TextValue" if I change the variable name to match the property name "Status" everything works. The gotcha is my component will be bound to different fields so I would need multiple versions defeating the purpose of creating a component.

Mike

[rockfordlhotka]

It does sound like the CSLA validator should ignore non CSLA source objects.

[MarkOverstreet]

Mike, the way we got around this was to simply copy the CSLAValidator class into our project, renamed it (ex: CSLAValidatorExtended) and added code to eat the exception and then we used that tag in place of the original. Not the cleanest but we had to get our project done and this worked perfectly for us.

[rockfordlhotka]

@MarkOverstreet btw, if you have tested code that you can share, that'd make it safer/easier to change the CSLA code 😉

[rockfordlhotka]

Added to backlog: #2462