| | | 1 | | using Microsoft.EntityFrameworkCore.Query; |
| | | 2 | | using System.Diagnostics; |
| | | 3 | | using System.Reflection; |
| | | 4 | | |
| | | 5 | | namespace Pozitron.QuerySpecification; |
| | | 6 | | |
| | | 7 | | public class IncludeEvaluator : IEvaluator |
| | | 8 | | { |
| | 1 | 9 | | private static readonly MethodInfo _includeMethodInfo = typeof(EntityFrameworkQueryableExtensions) |
| | 1 | 10 | | .GetTypeInfo().GetDeclaredMethods(nameof(EntityFrameworkQueryableExtensions.Include)) |
| | 3 | 11 | | .Single(mi => mi.IsPublic && mi.GetGenericArguments().Length == 2 |
| | 3 | 12 | | && mi.GetParameters()[0].ParameterType.GetGenericTypeDefinition() == typeof(IQueryable<>) |
| | 3 | 13 | | && mi.GetParameters()[1].ParameterType.GetGenericTypeDefinition() == typeof(Expression<>)); |
| | | 14 | | |
| | 1 | 15 | | private static readonly MethodInfo _thenIncludeAfterReferenceMethodInfo |
| | 1 | 16 | | = typeof(EntityFrameworkQueryableExtensions) |
| | 1 | 17 | | .GetTypeInfo().GetDeclaredMethods(nameof(EntityFrameworkQueryableExtensions.ThenInclude)) |
| | 3 | 18 | | .Single(mi => mi.IsPublic && mi.GetGenericArguments().Length == 3 |
| | 3 | 19 | | && mi.GetParameters()[0].ParameterType.GenericTypeArguments[1].IsGenericParameter |
| | 3 | 20 | | && mi.GetParameters()[0].ParameterType.GetGenericTypeDefinition() == typeof(IIncludableQueryable<,>) |
| | 3 | 21 | | && mi.GetParameters()[1].ParameterType.GetGenericTypeDefinition() == typeof(Expression<>)); |
| | | 22 | | |
| | 1 | 23 | | private static readonly MethodInfo _thenIncludeAfterEnumerableMethodInfo |
| | 1 | 24 | | = typeof(EntityFrameworkQueryableExtensions) |
| | 1 | 25 | | .GetTypeInfo().GetDeclaredMethods(nameof(EntityFrameworkQueryableExtensions.ThenInclude)) |
| | 3 | 26 | | .Single(mi => mi.IsPublic && mi.GetGenericArguments().Length == 3 |
| | 3 | 27 | | && !mi.GetParameters()[0].ParameterType.GenericTypeArguments[1].IsGenericParameter |
| | 3 | 28 | | && mi.GetParameters()[0].ParameterType.GetGenericTypeDefinition() == typeof(IIncludableQueryable<,>) |
| | 3 | 29 | | && mi.GetParameters()[1].ParameterType.GetGenericTypeDefinition() == typeof(Expression<>)); |
| | | 30 | | |
| | 2 | 31 | | private IncludeEvaluator() { } |
| | 1 | 32 | | public static IncludeEvaluator Instance = new(); |
| | | 33 | | |
| | | 34 | | public IQueryable<T> Evaluate<T>(IQueryable<T> source, Specification<T> specification) where T : class |
| | | 35 | | { |
| | 120 | 36 | | foreach (var includeString in specification.IncludeStrings) |
| | | 37 | | { |
| | 9 | 38 | | source = source.Include(includeString); |
| | | 39 | | } |
| | | 40 | | |
| | 220 | 41 | | foreach (var includeExpression in specification.IncludeExpressions) |
| | | 42 | | { |
| | 59 | 43 | | if (includeExpression.Type == IncludeTypeEnum.Include) |
| | | 44 | | { |
| | 27 | 45 | | source = BuildInclude<T>(source, includeExpression); |
| | | 46 | | } |
| | 32 | 47 | | else if (includeExpression.Type == IncludeTypeEnum.ThenInclude) |
| | | 48 | | { |
| | 32 | 49 | | source = BuildThenInclude<T>(source, includeExpression); |
| | | 50 | | } |
| | | 51 | | } |
| | | 52 | | |
| | 51 | 53 | | return source; |
| | | 54 | | } |
| | | 55 | | |
| | | 56 | | private static IQueryable<T> BuildInclude<T>(IQueryable source, IncludeExpression includeExpression) |
| | | 57 | | { |
| | | 58 | | Debug.Assert(includeExpression is not null); |
| | | 59 | | |
| | 27 | 60 | | var result = _includeMethodInfo |
| | 27 | 61 | | .MakeGenericMethod(includeExpression.EntityType, includeExpression.PropertyType) |
| | 27 | 62 | | .Invoke(null, [source, includeExpression.LambdaExpression]); |
| | | 63 | | |
| | | 64 | | Debug.Assert(result is not null); |
| | | 65 | | |
| | 27 | 66 | | return (IQueryable<T>)result; |
| | | 67 | | } |
| | | 68 | | |
| | | 69 | | private static IQueryable<T> BuildThenInclude<T>(IQueryable source, IncludeExpression includeExpression) |
| | | 70 | | { |
| | | 71 | | Debug.Assert(includeExpression is not null); |
| | | 72 | | Debug.Assert(includeExpression.PreviousPropertyType is not null); |
| | | 73 | | |
| | 32 | 74 | | var result = (IsGenericEnumerable(includeExpression.PreviousPropertyType, out var previousPropertyType) |
| | 32 | 75 | | ? _thenIncludeAfterEnumerableMethodInfo |
| | 32 | 76 | | : _thenIncludeAfterReferenceMethodInfo) |
| | 32 | 77 | | .MakeGenericMethod(includeExpression.EntityType, previousPropertyType, includeExpression.PropertyType) |
| | 32 | 78 | | .Invoke(null, [source, includeExpression.LambdaExpression]); |
| | | 79 | | |
| | | 80 | | Debug.Assert(result is not null); |
| | | 81 | | |
| | 32 | 82 | | return (IQueryable<T>)result; |
| | | 83 | | } |
| | | 84 | | |
| | | 85 | | private static bool IsGenericEnumerable(Type type, out Type propertyType) |
| | | 86 | | { |
| | 32 | 87 | | if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IEnumerable<>)) |
| | | 88 | | { |
| | 17 | 89 | | propertyType = type.GenericTypeArguments[0]; |
| | 17 | 90 | | return true; |
| | | 91 | | } |
| | | 92 | | |
| | 15 | 93 | | propertyType = type; |
| | 15 | 94 | | return false; |
| | | 95 | | } |
| | | 96 | | } |