luticate2-api/Luticate2.Utils/Dbo/OrderBy/LuOrderByBinder.cs

using System.Collections.Generic;
using System.Threading.Tasks;
using Luticate2.Utils.Dbo.Result;
using Microsoft.AspNetCore.Mvc.ModelBinding;

namespace Luticate2.Utils.Dbo.OrderBy
{
    public class LuOrderByBinder : IModelBinder
    {
        public static LuResult<LuOrderByDbo> FromString(string data)
        {
            if (data == null)
            {
                data = "";
            }
            data = data.Trim();
            if (data != "")
            {
                var dbo = new LuOrderByDbo {Fields = new List<LuOrderByFieldDbo>()};
                var fields = data.Split(',');
                foreach (var field in fields)
                {
                    if (field == "")
                    {
                        return LuResult<LuOrderByDbo>.Error(LuStatus.InputError,
                            string.Format("LuOrderByBinder: {0}", data), "Empty order by field");
                    }
                    var value = new LuOrderByFieldDbo();
                    var split = field.Split(':');
                    if (split.Length > 2 || split.Length == 0)
                    {
                        return LuResult<LuOrderByDbo>.Error(LuStatus.InputError,
                            string.Format("LuOrderByBinder: {0}", data), "Invalid field syntax");
                    }
                    value.Name = split[0];
                    var order = split.Length == 2 ? split[1].ToLower() : "asc";
                    if (order == "asc")
                    {
                        value.Asc = true;
                    }
                    else if (order == "desc")
                    {
                        value.Asc = false;
                    }
                    else
                    {
                        return LuResult<LuOrderByDbo>.Error(LuStatus.InputError,
                            string.Format("LuOrderByBinder: {0}", data), "Empty order by field order");
                    }
                    dbo.Fields.Add(value);
                }
                return LuResult<LuOrderByDbo>.Ok(dbo);
            }
            return LuResult<LuOrderByDbo>.Error(LuStatus.InputError, "Order by is empty or missing", "");
        }

        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            var messageTypeResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
            var res = FromString(messageTypeResult.FirstValue);
            if (res)
            {
                bindingContext.Result = ModelBindingResult.Success(res.Data);
            }
            else
            {
                bindingContext.Result = ModelBindingResult.Failed();
            }
            return Task.FromResult(0);
        }
    }

    public class LuOrderByBinderProvider : IModelBinderProvider
    {
        public IModelBinder GetBinder(ModelBinderProviderContext context)
        {
            if (context.Metadata.ModelType == typeof(LuOrderByDbo))
            {
                return new LuOrderByBinder();
            }
            return null;
        }
    }
}