C# 8

Pattern matching

using UIDef.Lists.Data.Core;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using UIDef.Core.Domain;
using System;
using UIDef.Lists.Data.Core.Domain;
using CSharpFunctionalExtensions;
using UIDef.Lists.Requests.GetFromatters;
using UIDef.Core.MediatR.CRUDHandlers.GetList;

namespace UIDef.Lists.Domain.Requests.Formatters.GetFromatters
{

    public class GetFormattersHandler : GetListHandler<GetFormattersRequest, Formatter, GetFormattersResultItem, GetFormattersFilterDTO, SortFieldsDTO>
    {
        private readonly IUnitOfWork _unitOfWork;

        public GetFormattersHandler(IUnitOfWork unitOfWork, ICheckProjectPermission checkProjectPermission)
            : base(checkProjectPermission)
        {
            _unitOfWork = unitOfWork;
        }


        protected override IQueryable<Formatter> OnGetQuery(int projectId) =>
            _unitOfWork.Formatters.GetAll().Where(p => p.ProjectId == projectId);

        protected override Func<Formatter, dynamic> OnOrder(SortFieldsDTO sort) => sort switch
        {
            SortFieldsDTO.Name => x => x.Name,
            SortFieldsDTO.ValueType => x => x.ValueType,
            { } => throw new ArgumentOutOfRangeException()
        };

        protected override IQueryable<Formatter> OnFilter(IQueryable<Formatter> q, GetFormattersFilterDTO filter) => filter switch
        {
            { Name: var name } when name != null => q.Where(p => EF.Functions.Like(p.Name, $"%{name}%")),
            _ => q
        };

        protected override GetFormattersResultItem OnMapItem(Formatter item) => new GetFormattersResultItem(
                item.Id,
                item.Name,
                item.ValueType,
                item.Description
                );
    }
}