Umbraco Forms - to populate the prevalues with a data-source from a Contentment data-editor

ContentmentDataSourcePreValueSource.cs

/* Copyright © 2021 Lee Kelleher.
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json.Linq;
using Umbraco.Community.Contentment.DataEditors;
using Umbraco.Core.Services;
using Umbraco.Forms.Core.Models;
using Umbraco.Forms.Core.Providers.PreValues;

namespace Umbraco.Community.Contentment.Forms.PreValueSources
{
    internal sealed class ContentmentDataSourcePreValueSource : UmbracoPreValuesReadOnly
    {
        private readonly ConfigurationEditorUtility _configurationEditorUtility;
        private readonly IDataTypeService _dataTypeService;
        private readonly Dictionary<string, string> _dataSourceKeys;

        public ContentmentDataSourcePreValueSource(ConfigurationEditorUtility configurationEditorUtility, IDataTypeService dataTypeService)
        {
            _configurationEditorUtility = configurationEditorUtility;
            _dataTypeService = dataTypeService;
            _dataSourceKeys = new Dictionary<string, string>()
            {
                { "DataList", "dataSource" },
                { "TextInput", "items" },
            };

            Id = new Guid("44578A69-9F9D-443F-8DC7-2512B0877F98");
            Name = "[Contentment] Data Source";
            Description = "Populates the prevalues with a data-source from a Contentment data-editor.";
        }

        public override List<PreValue> GetPreValues(Field field, Form form)
        {
            if (int.TryParse(DataTypeId, out var dataTypeId) == true && dataTypeId > 0)
            {
                var dataType = _dataTypeService.GetDataType(dataTypeId);
                if (dataType != null && _dataSourceKeys.TryGetValue(dataType.EditorAlias, out var dataSourceKey) == true)
                {
                    if (dataType.Configuration is Dictionary<string, object> config &&
                        config.TryGetValue(dataSourceKey, out var obj1) == true &&
                        obj1 is JArray array1 &&
                        array1.Count > 0 &&
                        array1[0] is JObject item1)
                    {
                        var source = _configurationEditorUtility.GetConfigurationEditor<IDataListSource>(item1.Value<string>("key"));
                        if (source != null)
                        {
                            var sourceConfig = item1["value"].ToObject<Dictionary<string, object>>();
                            var items = source?.GetItems(sourceConfig);
                            if (items?.Any() == true)
                            {
                                return items.Select(x => new PreValue { Id = x.Value, Value = x.Name, }).ToList();
                            }
                        }

                    }
                }
            }

            // Fallback on the base method from `UmbracoPreValuesReadOnly`. ¯\_(ツ)_/¯
            return base.GetPreValues(field, form);
        }
    }
}