[BUG] A custom dropdown options provider is not working

[jayachandra21]

Description

A custom dropdown options provider is not working.

Steps to Reproduce

1. Detailed Steps:

• Class with VehicleUIHandler which inherits from DropDownOptionsProviderBase.

public class VehicleUIHandler : DropDownOptionsProviderBase
{
    private readonly Random _random = new();

    protected override ValueTask<ICollection<SelectListItem>> GetItemsAsync(PropertyInfo propertyInfo, object? context, CancellationToken cancellationToken)
    {
        var items = new List<SelectListItem>
        {
            new("BMW", "1"),
            new("Tesla", "2"),
            new("Peugeot", "3"),
            new(_random.Next(100).ToString(), "4")
        };

        return new(items);
    }
}

• Configures the specified property to refresh the UI when the property value changes.

public class RefreshUIHandler : IPropertyUIHandler
{
    public ValueTask<IDictionary<string, object>> GetUIPropertiesAsync(PropertyInfo propertyInfo, object? context, CancellationToken cancellationToken = default)
    {
        IDictionary<string, object> result = new Dictionary<string, object>
        {
            { "Refresh", true }
        };
        return ValueTask.FromResult(result);
    }
}

• Register in the UI handler.

builder.Services.AddSingleton<VehicleUIHandler>();

• Custom Activity VehicleActivity

public class VehicleActivity : Activity<string>
{
    [Input(
        Description = "The content type to use when sending the request.",
        UIHint = InputUIHints.DropDown,
        UIHandlers = [typeof(VehicleUIHandler), typeof(RefreshUIHandler)]
    )]
    public Input<string> Brand { get; set; } = default!;
}

• In the activity Input property is shows the empty list

2. Reproduction Rate: every time

3. Additional Configuration:

   • Used the sample application as reference
     https://github.com/elsa-workflows/elsa-samples/tree/main/src/aspnet/Elsa.Samples.AspNet.CustomUIHandler

Expected Behavior

The Vehicle activity suppose to show the list items mentioned in the VehicleUIHandler.

Actual Behavior

It not listing the items. It means dropdown is empty.

Environment

• Elsa Package Version: Elsa 3.3.0 RC3
• Operating System: Windows
• Browser and Version: Chrome

Troubleshooting Attempts

• Tried to debug the VehicleUIHandler class but debugger is not hitting the same class.

[sfmskywalker]

Turned out that the sample project registered the handler incorrectly. Here's how to do it correctly:

builder.Services.AddScoped<IPropertyUIHandler, VehicleUIHandler>();
builder.Services.AddScoped<IPropertyUIHandler, RefreshUIHandler>();

After doing that, it will work.
The sample project has been updated.

Thanks for reporting!

[Suchiman]

Huh indeed, that fixed it, in 3.1 it was not necessary to register them with DI at all but in 3.3 it doesn't work without it being registered.