BTCPayServerPlugins/Plugins/BTCPayServer.Plugins.Prism/Components/ValidationMessage2.razor

@using System.Linq.Expressions
@typeparam TValue
@implements IDisposable

@foreach (var message in EditContext.GetValidationMessages(_fieldIdentifier))
{
    <div @attributes="InputAttributes">
        @message
    </div>
}

@code {

    [CascadingParameter]
    private EditContext EditContext { get; set; }

    [Parameter]
    public Expression<Func<TValue>> For { get; set; }
    
    [Parameter(CaptureUnmatchedValues = true)]
    public Dictionary<string, object>? InputAttributes { get; set; }

    private FieldIdentifier _fieldIdentifier;

    protected override void OnInitialized()
    {
        _fieldIdentifier = FieldIdentifier.Create(For);
        EditContext.OnValidationStateChanged += HandleValidationStateChanged;
    }

    private void HandleValidationStateChanged(object o, ValidationStateChangedEventArgs args) => StateHasChanged();

    public void Dispose()
    {
        EditContext.OnValidationStateChanged -= HandleValidationStateChanged;
    }

}