inabox/InABox.DynamicGrid/FormDesigner/Controls/Fields/DFLookupControl.cs

using InABox.Clients;
using InABox.Core;
using NPOI.SS.Formula.Functions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace InABox.DynamicGrid
{
    public class DFLookupControl : DynamicFormFieldControl<DFLayoutLookupField, DFLayoutLookupFieldProperties, string>
    {
        private ComboBox Combo = null!; // late-initialising

        protected override FrameworkElement Create()
        {
            Combo = new ComboBox();
            var type = CoreUtils.GetEntity(Field.Properties.LookupType);
            if (type != null)
            {
                var client = ClientFactory.CreateClient(type);
                //Task.Run(() =>
                //{
                var table = client.Query(
                    LookupFactory.DefineFilter(type),
                    LookupFactory.DefineColumns(type),
                    LookupFactory.DefineSort(type)
                );
                var lookups = new Dictionary<Guid, string>();
                foreach (var row in table.Rows)
                {
                    var id = row.Get<Guid>("ID");
                    Dictionary<string, object> values = row.ToDictionary(new[] { "ID" });
                    var display = LookupFactory.FormatLookup(type, values, new string[] { });
                    lookups[id] = display;
                }
                //Dispatcher.Invoke(() =>
                //{

                Combo.DisplayMemberPath = "Value";
                Combo.SelectedValuePath = "Key";
                Combo.ItemsSource = lookups;
                Combo.VerticalContentAlignment = VerticalAlignment.Center;
                Combo.SelectionChanged += (sender, e) => ChangeField();
                //});

                //});
            }

            return Combo;
        }

        public override object? GetEntityValue()
        {
            return (Guid?)Combo.SelectedValue ?? Guid.Empty;
        }

        public override void SetEntityValue(object? value)
        {
            Combo.SelectedValue = value;
        }

        public override string GetValue() => ((KeyValuePair<Guid, string>?)Combo.SelectedItem)?.Value ?? "";

        public override void SetValue(string? value)
        {
            var lookups = Combo.ItemsSource as Dictionary<Guid, string>;
            if (lookups is null)
                return;
            var lookup = lookups!.FirstOrDefault(x => x.Value == value);
            Combo.SelectedItem = lookup;
        }
        protected override bool IsEmpty() => Combo.SelectedValue == null || (Guid)Combo.SelectedValue == Guid.Empty;
    }
}