Blazor OnPropertyChanged and Custom AddBusinessRules

[jhuerta3]

Hello all,

Im have been trying to figure this out. I cant seem to call the database from the BusinessEdit object OnPropertyChange method and also from AddBusinessRules method. I keep getting the following error, "Synchronous data access is not supported on this runtime. Please use async data access methods" I tried several things but no luck. I tried to change the OnPropertyChange to async but I could not find any methods to convert them to async. This works fine from the razor pages since they are all async. So basically the question is how do I access the database from the server side/business objects. Im not sure if the ApplicationContext.GetRequiredService is the correct way to do it.

I will keep doing some research. Thank you.

    protected override void OnPropertyChanged(IPropertyInfo propertyInfo)
    {
        base.OnPropertyChanged(propertyInfo);
        if (propertyInfo == StatusIDProperty)
        {
            if (StatusID.ToString() != null && StatusID.ToString() != "00000000-0000-0000-0000-000000000000")
            {
                LookUpTableInfoPortal = ApplicationContext.GetRequiredService<IDataPortal<LookUpTableInfo>>();
                LookUpTableFactory objLookFactory = new LookUpTableFactory(LookUpTableInfoPortal);
                LookUpTableInfo objStatus = objLookFactory.GetkLookUpInfo(StatusID);

                if (objStatus.LookUpName.Equals(SystemEnums.EquipmentStatusEnum.Obsolete) || 
                    objStatus.LookUpName.Equals(SystemEnums.EquipmentStatusEnum.Damaged))
                    ActiveFlag = false;
                else
                    ActiveFlag = true;
            }
        }
    }

and

    protected override void AddBusinessRules()
    {
        LookUpTableInfoPortal = ApplicationContext.GetRequiredService<IDataPortal<LookUpTableInfo>>();
        base.AddBusinessRules();
        BusinessRules.AddRule(new CheckStatusChange(StatusIDProperty, ActiveFlag, LookUpTableInfoPortal));
    }

and

public class CheckStatusChange : BusinessRule
{
    Csla.IDataPortal<AssetMgmtSystem.Shared.LookUpTableInfo> LookUpTableInfoPortal;
    public bool ActiveFlagStatus { get; set; }

    public CheckStatusChange(Csla.Core.IPropertyInfo primaryProperty, 
                             bool activeflagstatus, 
                             Csla.IDataPortal<App.Shared.LookUpTableInfo> lookuttableinfoportal)
      : base(primaryProperty)
    {
        ActiveFlagStatus = activeflagstatus;
        LookUpTableInfoPortal = lookuttableinfoportal;
    }

    protected override void Execute(IRuleContext context)
    {
        var StatusIDValue = (Guid)ReadProperty(context.Target, PrimaryProperty);

            if (StatusIDValue.ToString() != null && StatusIDValue.ToString() != "00000000-0000-0000-0000-000000000000")
            {
                LookUpTableFactory objLookFactory = new LookUpTableFactory(LookUpTableInfoPortal);
                LookUpTableInfo objStatus = objLookFactory.GetkLookUpInfo(StatusIDValue);

                if ((objStatus.LookUpName.Equals(SystemEnums.EquipmentStatusEnum.Obsolete) || objStatus.LookUpName.Equals(SystemEnums.EquipmentStatusEnum.Damaged)) && ActiveFlagStatus == true)
                    context.AddWarningResult("Check avilability. Active flag should be false for status.");
            }
        return;
    }
}

[Chicagoan2016]

I didn't understand your 'use case' : ) but here is something I have done in the past (no DI back then)
In my business rule class (inside Execute method) I called either a command object or readonly collection object to get values I needed.

[rockfordlhotka]

The exception is telling you that your code is running in a .NET runtime environment where synchronous server calls aren't supported, so your data portal calls need to be async. It isn't about your calling code (what you are showing here), it is about the called code - specifically where you are actually using the data portal.

Your GetkLookUpInfo method must be doing a Fetch instead of FetchAsync - or something like that.

[jhuerta3]

Hello Both, I see what you mean. Yes my GetLookUpInfo was using the following

    public LookUpTableInfo GetkLookUpInfo(Guid LookUpID)
    {
        return Portal.Fetch(LookUpID);
    }

I changed it to the following.

    public async Task<LookUpTableInfo> GetkLookUpInfoAsync(Guid LookUpID)
    {
        return await Portal.FetchAsync(LookUpID);
    }

I will run some test and get back to you.
Thank you for your help.

[jhuerta3]

After doing some research I found the issue it was a combination of two things. First, I had to correct my code to the following which still needs some work:

    protected override async void OnPropertyChanged(IPropertyInfo propertyInfo)
    {
        base.OnPropertyChanged(propertyInfo);
        if (propertyInfo == StatusIDProperty)
        {
            if (StatusID != Guid.Parse("00000000-0000-0000-0000-000000000000"))
            {
                LookUpTableInfoPortal = ApplicationContext.GetRequiredService<IDataPortal<LookUpTableInfo>>();
                LookUpTableFactory objLookFactory = new LookUpTableFactory(LookUpTableInfoPortal);
                Task<LookUpTableInfo> objStatusTask = objLookFactory.GetkLookUpInfoAsync(StatusID);
                LookUpTableInfo objStatus = await objStatusTask;

                ActiveFlag = !objStatus.LookUpName.ToLower().Equals("Obsolete".ToLower()) &&
                                !objStatus.LookUpName.ToLower().Equals("Damaged".ToLower());
            }
        }
    }

Then I realized that when I debug on a break point my IDE would freeze. I thought the code wasn’t working. After I removed all the break points it ran without any issues. I got another problem but I will ask another question, so it has its own topic.

[rockfordlhotka]

I've had my share of issues with debugging in Blazor projects too. No good solution to offer, just my empathy.