Get proper generic type in RunSubquery method

Author: ddidgdimitrov-infragistics

QueryExecutor.cs

@@ -1,16 +1,17 @@
-using AutoMapper;
-using AutoMapper.Internal;
-using AutoMapper.QueryableExtensions;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Swashbuckle.AspNetCore.SwaggerGen;
+using System.Collections.Generic;
 using System.Globalization;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Reflection.Emit;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
+using AutoMapper;
+using AutoMapper.Internal;
+using AutoMapper.QueryableExtensions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Swashbuckle.AspNetCore.SwaggerGen;
 
 namespace Infragistics.QueryBuilder.Executor
 {
@@ -33,6 +34,15 @@ public static object[] Run<TSource, TTarget>(this IQueryable<TSource> source, Qu
             return db is not null ? BuildQuery<TSource, TTarget>(db, source, query, mapper).ToArray() : Array.Empty<object>();
         }
 
+        public static MethodInfo? GetGenericMethod(Type executorType, int attributeCount, Type[] genericArgs)
+        {
+            var method = executorType
+                .GetMethods(BindingFlags.Static | BindingFlags.Public)
+                .FirstOrDefault(m => m.CustomAttributes.Count() == attributeCount);
+
+            return method?.MakeGenericMethod(genericArgs);
+        }
+
         private static IQueryable<object> BuildQuery<TSource, TTarget>(DbContext db, IQueryable<TSource> source, Query? query, IMapper? mapper = null)
         {
             if (query is null)
@@ -224,7 +234,21 @@ private static IEnumerable<dynamic> RunSubquery(DbContext db, Query? query)
         {
             var t = query?.Entity.ToLower(CultureInfo.InvariantCulture) ?? string.Empty;
             var p = db.GetType().GetProperty(t, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance) ?? throw new InvalidOperationException($"Property '{t}' not found on type '{db.GetType()}'");
-            return p.GetValue(db) is not IQueryable<dynamic> q ? Array.Empty<dynamic>() : [.. q.Run(query)];
+
+            var methods = typeof(QueryExecutor).GetMethods(BindingFlags.Static | BindingFlags.Public);
+            var method = methods?.FirstOrDefault(m => m.CustomAttributes.Count() == 1);
+            var dbSet = p.GetValue(db);
+            var genericType = p.PropertyType.GetGenericArguments().FirstOrDefault();
+
+            if (dbSet != null && genericType != null)
+            {
+
+                var genericMethod = GetGenericMethod(typeof(QueryExecutor), 1, [genericType]);
+
+                var queryable = dbSet?.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null);
+                return genericMethod?.Invoke(null, [queryable, query]) as IEnumerable<dynamic> ?? Array.Empty<dynamic>();
+            }
+            return Enumerable.Empty<dynamic>();
         }
 
         private static dynamic? ProjectField(object? obj, string field)
@@ -242,13 +266,18 @@ private static Expression GetSearchValue(JsonValue? jsonVal, Type targetType)
             }
 
             var nonNullableType = Nullable.GetUnderlyingType(targetType) ?? targetType;
-            var value = jsonVal.Deserialize(targetType);
 
-            if (nonNullableType.IsEnum && value is string)
+            if (nonNullableType.IsEnum)
             {
-                return Expression.Constant(Enum.Parse(nonNullableType, (string)value));
+                var enumValue = jsonVal.Deserialize<string>();
+                if (enumValue != null)
+                {
+                    return Expression.Constant(Enum.Parse(nonNullableType, enumValue));
+                }
             }
 
+            var value = jsonVal.Deserialize(targetType);
+
             var convertedValue = Convert.ChangeType(value, nonNullableType, CultureInfo.InvariantCulture);
             return Expression.Constant(convertedValue, targetType);
         }

Services/QueryBuilderService.cs

@@ -18,27 +18,18 @@ public Dictionary<string, object[]> RunQuery(Query query)
                 .FirstOrDefault(p => p.PropertyType.IsGenericType && p.Name.ToLower(CultureInfo.InvariantCulture) == t && p.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>));
             if (propInfo != null)
             {
-                var methods = typeof(QueryExecutor).GetMethods(BindingFlags.Static | BindingFlags.Public);
-                var method = methods?.FirstOrDefault(m => m.CustomAttributes.Count() == 2);
-
                 var dbSet = propInfo.GetValue(db);
                 var dbGenericType = dbSet?.GetType()?.GenericTypeArguments.FirstOrDefault();
-                if (dbGenericType != null && dbSet != null)
+                var dtoGenericType = typeof(TResults).GetProperty(propInfo.Name)?.PropertyType.GetElementType();
+
+                if (dbSet != null && dbGenericType != null && dtoGenericType != null)
                 {
-                    var dtoGenericType = typeof(TResults).GetProperty(propInfo.Name)?.PropertyType.GetElementType();
-                    if (dtoGenericType != null)
-                    {
-                        var genericMethod = method?.MakeGenericMethod(dbGenericType, dtoGenericType);
+                    var genericMethod = QueryExecutor.GetGenericMethod(typeof(QueryExecutor), 2, [dbGenericType, dtoGenericType]);
 
-                        var asQueryableMethod = dbSet.GetType().GetMethod("AsQueryable");
-                        var queryable = asQueryableMethod?.Invoke(dbSet, null);
-                        if (queryable != null)
-                        {
-                            if (genericMethod?.Invoke(null, [queryable, query, mapper]) is object[] propRes)
-                            {
-                                return new Dictionary<string, object[]> { { propInfo.Name, propRes } };
-                            }
-                        }
+                    var queryable = dbSet.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null);
+                    if (queryable != null && genericMethod?.Invoke(null, [queryable, query, mapper]) is object[] propRes)
+                    {
+                        return new Dictionary<string, object[]> { { propInfo.Name.ToLowerInvariant(), propRes } };
                     }
                 }
             }