QueryExtensions helper for dynamic build LINQ queries using Extensions and dynamic LINQ

QueryExtensions.cs

using KindergartenApp.Core.Extensions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Dynamic;
using System.Linq.Expressions;
using System.Reflection;
using KindergartenApp.Core.Filtering;

namespace KindergartenApp.Core.Extensions
{
    public static class QueryableExtensions
    {
        public static IQueryable<T> SortIQueryable<T>(this IQueryable<T> data, string fieldName, string sortOrder)
        {
            if (string.IsNullOrWhiteSpace(fieldName)) return data;
            if (string.IsNullOrWhiteSpace(sortOrder)) return data;

            var param = Expression.Parameter(typeof(T), "i");

            MemberExpression property = null;
            string[] fieldNames = fieldName.Split('.');
            foreach (string filed in fieldNames)
            {
                property = property == null ? Expression.Property(param, filed) : Expression.Property(property, filed);
            }
            
            if (property.Type.IsValueType)
            {
                Expression valConvertion = Expression.ConvertChecked(property, property.Type);

                if (property.Type == typeof(int))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, int>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(double))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, double>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(long))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, long>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(byte))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, byte>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(bool))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, bool>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(bool?))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, bool?>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
                if (property.Type == typeof(DateTime))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, DateTime>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }

                if (property.Type == typeof(DateTime?))
                {
                    var myValSortExpression = Expression.Lambda<Func<T, DateTime?>>(valConvertion, param);

                    return (sortOrder == "desc") ? data.OrderByDescending(myValSortExpression)
                    : data.OrderBy(myValSortExpression);
                }
            }

            Expression conversion = Expression.ConvertChecked(property, property.Type);
            var mySortExpression = Expression.Lambda<Func<T, object>>(conversion, param);

            return (sortOrder == "desc") ? data.OrderByDescending(mySortExpression)
                : data.OrderBy(mySortExpression);
        }

        public static IQueryable<T> WhereQueryable<T>(this IQueryable<T> data, IList<FilterModel> filters)
        {
            var separator = " || ";

            var itemstType = typeof(T);
            var containsPredicate = new List<string>();
            var numbersPredicate = new List<string>();
            var dateTimePredicate = new List<string>();

            foreach (var filter in filters)
            {
                var isNested = filter.Name.Contains(".");

                if (isNested)
                {
                    containsPredicate.Add($"{filter.Name}.Contains(\"{filter.Term}\")");
                    continue;
                }

                var propertyType = itemstType.GetProperty(filter.Name);
                if (propertyType != null)
                {
                    var filterType = propertyType.PropertyType;

                    if (filterType == typeof(string))
                    {
                        containsPredicate.Add($"{filter.Name}.Contains(\"{filter.Term}\")");
                    }

                    if (filterType == typeof(long) || filterType == typeof(int) || filterType == typeof(byte))
                    {
                        numbersPredicate.Add($"{filter.Name} = {filter.Term}");
                    }

                    if (filterType == typeof(DateTime))
                    {
                     //   itmes = items.Where(string.Format("{0} > @0", searchField),
                     //DateTime.Parse(searchString));

                        var dt = DateTime.Parse(filter.Term);
                        //dateTimePredicate.Add($"{filter.Name} = Date({dt.Date.Year}, {dt.Date.Month}, {dt.Date.Day})");
                        //dateTimePredicate.Add($"{filter.Name} == DateTime.Parse(\"{filter.Term}\")");
                        //dateTimePredicate.Add($"DbFunctions.TruncateTime({filter.Name}) == {dt}");
                    }
                }
            }

            var predicate = string.Join(separator, containsPredicate);

            if (!string.IsNullOrEmpty(predicate))
                data = data.Where(predicate);

            var numPredicate = string.Join(separator, numbersPredicate);

            if(!string.IsNullOrEmpty(numPredicate))
                data = data.Where(numPredicate);

            var dtPredicate = string.Join(separator, dateTimePredicate);

            if (!string.IsNullOrEmpty(dtPredicate))
                data = data.Where(dtPredicate);

            return data;
        }

        public static Expression<Func<T, bool>> False<T>() { return f => false; }

        public static Expression<Func<T, bool>> In<T, TValue>(this Expression<Func<T, bool>> predicate, string propertyName, List<TValue> values)
        {
            var param = predicate.Parameters.Single();
            MemberExpression property = Expression.PropertyOrField(param, propertyName);
            var micontain = typeof(List<TValue>).GetMethod("Contains");
            var mc = Expression.Call(Expression.Constant(values), micontain, property);
            return Expression.Lambda<Func<T, bool>>(mc, param);
        }
    }
}