分页排序和多条件查询

src/HelloShop.ServiceDefaults/Extensions/QueryableExtensions.cs

@@ -0,0 +1,78 @@
+using HelloShop.ServiceDefaults.Constants;
+using HelloShop.ServiceDefaults.Models.Paging;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace HelloShop.ServiceDefaults.Extensions;
+
+public static class QueryableExtensions
+{
+    public static IQueryable<TEntity> SortBy<TEntity>(this IQueryable<TEntity> query, string? orderBy = null)
+    {
+        PropertyInfo[] properties = typeof(TEntity).GetProperties();
+
+        IOrderedQueryable<TEntity>? orderedQueryable = null;
+
+        if (!string.IsNullOrWhiteSpace(orderBy))
+        {
+            // Convert expressions of the form field1 desc,field2 asc
+
+            string[] orderBySubs = orderBy.Split(',');
+
+            foreach (var orderBySub in orderBySubs)
+            {
+                string[] orderByParts = orderBySub.Trim().Split(' ');
+
+                if (orderByParts.Length >= 1)
+                {
+                    string propertyName = PascalCaseNamingPolicy.PascalCase.ConvertName(orderByParts[0]);
+
+                    bool ascending = orderByParts.Length == 1 || (orderByParts.Length == 2 && orderByParts[1].Equals("asc", StringComparison.OrdinalIgnoreCase));
+
+                    if (properties.Any(x => x.Name == propertyName))
+                    {
+                        if (ascending)
+                        {
+                            orderedQueryable = orderedQueryable is null ? query.OrderBy(propertyName) : orderedQueryable.ThenBy(propertyName);
+                        }
+                        else
+                        {
+                            orderedQueryable = orderedQueryable is null ? query.OrderByDescending(propertyName) : orderedQueryable.ThenByDescending(propertyName);
+                        }
+                    }
+                }
+            }
+        }
+
+        if (orderedQueryable is null)
+        {
+            string defaultPropertyName = properties.Any(x => x.Name == EntityConnstants.DefaultKey) ? EntityConnstants.DefaultKey : properties.First().Name;
+
+            orderedQueryable = query.OrderByDescending(defaultPropertyName);
+        }
+
+        return orderedQueryable;
+    }
+
+    public static IQueryable<TEntity> PageBy<TEntity>(this IQueryable<TEntity> query, PagedRequest pagedRequest)
+    {
+        return query.Skip((pagedRequest.PageNumber - 1) * pagedRequest.PageSize).Take(pagedRequest.PageSize);
+    }
+
+    public static IQueryable<TEntity> SortAndPageBy<TEntity>(this IQueryable<TEntity> query, PagedAndSortedRequest? pagedAndSortedRequest = null)
+    {
+        pagedAndSortedRequest ??= new PagedAndSortedRequest { PageNumber = 1, PageSize = PagingConstants.DefaultPageSize };
+
+        return query.SortBy(pagedAndSortedRequest.OrderBy).PageBy(pagedAndSortedRequest);
+    }
+
+    public static IQueryable<TSource> WhereIf<TSource>(this IQueryable<TSource> source, bool condition, Expression<Func<TSource, bool>> predicate)
+    {
+        return condition ? source.Where(predicate) : source;
+    }
+
+    public static IQueryable<TSource> WhereIf<TSource>(this IQueryable<TSource> source, bool condition, Expression<Func<TSource, int, bool>> predicate)
+    {
+        return condition ? source.Where(predicate) : source;
+    }
+}

src/HelloShop.ServiceDefaults/Extensions/QueryableOrderByExtensions.cs

@@ -0,0 +1,44 @@
+using System.Collections.Concurrent;
+using System.Linq.Expressions;
+
+namespace HelloShop.ServiceDefaults.Extensions;
+
+public static class QueryableOrderByExtensions
+{
+    public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string propertyName) => OrderingHelper<T>.OrderBy(source, propertyName);
+
+    public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string propertyName) => OrderingHelper<T>.OrderByDescending(source, propertyName);
+
+    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string propertyName) => OrderingHelper<T>.ThenBy(source, propertyName);
+
+    public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string propertyName) => OrderingHelper<T>.ThenByDescending(source, propertyName);
+
+    private static class OrderingHelper<TSource>
+    {
+        private static readonly ConcurrentDictionary<string, LambdaExpression> cached = new();
+
+        public static IOrderedQueryable<TSource> OrderBy(IQueryable<TSource> source, string propertyName) => Queryable.OrderBy(source, (dynamic)CreateLambdaExpression(propertyName));
+
+        public static IOrderedQueryable<TSource> OrderByDescending(IQueryable<TSource> source, string propertyName) => Queryable.OrderByDescending(source, (dynamic)CreateLambdaExpression(propertyName));
+
+        public static IOrderedQueryable<TSource> ThenBy(IOrderedQueryable<TSource> source, string propertyName) => Queryable.ThenBy(source, (dynamic)CreateLambdaExpression(propertyName));
+
+        public static IOrderedQueryable<TSource> ThenByDescending(IOrderedQueryable<TSource> source, string propertyName) => Queryable.ThenByDescending(source, (dynamic)CreateLambdaExpression(propertyName));
+
+        private static LambdaExpression CreateLambdaExpression(string propertyName)
+        {
+            if (cached.TryGetValue(propertyName, out LambdaExpression? value))
+            {
+                return value;
+            }
+
+            var parameter = Expression.Parameter(typeof(TSource));
+            var body = Expression.Property(parameter, propertyName);
+            var keySelector = Expression.Lambda(body, parameter);
+
+            cached[propertyName] = keySelector;
+
+            return keySelector;
+        }
+    }
+}

src/HelloShop.ServiceDefaults/Infrastructure/PascalCaseNamingPolicy.cs

@@ -0,0 +1,10 @@
+using System.Text.Json;
+
+namespace HelloShop.ServiceDefaults;
+
+public class PascalCaseNamingPolicy : JsonNamingPolicy
+{
+    public static PascalCaseNamingPolicy PascalCase { get; } = new PascalCaseNamingPolicy();
+
+    public override string ConvertName(string name) => string.Concat(char.ToUpper(name[0]), name[1..]);
+}

src/HelloShop.ServiceDefaults/Models/Paging/PagedAndSortedRequest.cs

@@ -2,5 +2,5 @@
 
 public class PagedAndSortedRequest : PagedRequest
 {
-    public IEnumerable<SortingOrder>? Sorts { get; init; }
-}
+    public string? OrderBy { get; init; }
+}

src/HelloShop.ServiceDefaults/Models/Paging/SortingOrder.cs

@@ -1,8 +0,0 @@
-namespace HelloShop.ServiceDefaults.Models.Paging;
-
-public class SortingOrder
-{
-    public required string PropertyName { get; init; }
-
-    public bool Ascending { get; init; }
-}