Removed dead code, cleaned up ResourceGraph and reduced collection copying

Author: Bart Koelman

src/JsonApiDotNetCore/Configuration/IResourceGraph.cs

@@ -18,62 +18,38 @@ public interface IResourceGraph : IResourceContextProvider
         /// all exposed fields are returned.
         /// </summary>
         /// <typeparam name="TResource">
-        /// The resource for which to retrieve fields.
+        /// The resource type for which to retrieve fields.
         /// </typeparam>
         /// <param name="selector">
-        /// Should be of the form: (TResource e) => new { e.Field1, e.Field2 }
+        /// Should be of the form: (TResource r) => new { r.Field1, r.Field2 }
         /// </param>
-        IReadOnlyCollection<ResourceFieldAttribute> GetFields<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        IReadOnlyCollection<ResourceFieldAttribute> GetFields<TResource>(Expression<Func<TResource, dynamic>> selector)
             where TResource : class, IIdentifiable;
 
         /// <summary>
-        /// Gets all attributes for <typeparamref name="TResource" /> that are targeted by the selector. If no selector is provided, all exposed fields are
+        /// Gets all attributes for <typeparamref name="TResource" /> that are targeted by the selector. If no selector is provided, all exposed attributes are
         /// returned.
         /// </summary>
         /// <typeparam name="TResource">
-        /// The resource for which to retrieve attributes.
+        /// The resource type for which to retrieve attributes.
         /// </typeparam>
         /// <param name="selector">
-        /// Should be of the form: (TResource e) => new { e.Attribute1, e.Attribute2 }
+        /// Should be of the form: (TResource r) => new { r.Attribute1, r.Attribute2 }
         /// </param>
-        IReadOnlyCollection<AttrAttribute> GetAttributes<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        IReadOnlyCollection<AttrAttribute> GetAttributes<TResource>(Expression<Func<TResource, dynamic>> selector)
             where TResource : class, IIdentifiable;
 
         /// <summary>
-        /// Gets all relationships for <typeparamref name="TResource" /> that are targeted by the selector. If no selector is provided, all exposed fields are
-        /// returned.
+        /// Gets all relationships for <typeparamref name="TResource" /> that are targeted by the selector. If no selector is provided, all exposed relationships
+        /// are returned.
         /// </summary>
         /// <typeparam name="TResource">
-        /// The resource for which to retrieve relationships.
+        /// The resource type for which to retrieve relationships.
         /// </typeparam>
         /// <param name="selector">
-        /// Should be of the form: (TResource e) => new { e.Relationship1, e.Relationship2 }
+        /// Should be of the form: (TResource r) => new { r.Relationship1, r.Relationship2 }
         /// </param>
-        IReadOnlyCollection<RelationshipAttribute> GetRelationships<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        IReadOnlyCollection<RelationshipAttribute> GetRelationships<TResource>(Expression<Func<TResource, dynamic>> selector)
             where TResource : class, IIdentifiable;
-
-        /// <summary>
-        /// Gets all exposed fields (attributes and relationships) for the specified type.
-        /// </summary>
-        /// <param name="type">
-        /// The resource type. Must implement <see cref="IIdentifiable" />.
-        /// </param>
-        IReadOnlyCollection<ResourceFieldAttribute> GetFields(Type type);
-
-        /// <summary>
-        /// Gets all exposed attributes for the specified type.
-        /// </summary>
-        /// <param name="type">
-        /// The resource type. Must implement <see cref="IIdentifiable" />.
-        /// </param>
-        IReadOnlyCollection<AttrAttribute> GetAttributes(Type type);
-
-        /// <summary>
-        /// Gets all exposed relationships for the specified type.
-        /// </summary>
-        /// <param name="type">
-        /// The resource type. Must implement <see cref="IIdentifiable" />.
-        /// </param>
-        IReadOnlyCollection<RelationshipAttribute> GetRelationships(Type type);
     }
 }

src/JsonApiDotNetCore/Configuration/JsonApiApplicationBuilder.cs

@@ -51,7 +51,7 @@ public JsonApiApplicationBuilder(IServiceCollection services, IMvcCoreBuilder mv
             var loggerFactory = _intermediateProvider.GetRequiredService<ILoggerFactory>();
 
             _resourceGraphBuilder = new ResourceGraphBuilder(_options, loggerFactory);
-            _serviceDiscoveryFacade = new ServiceDiscoveryFacade(_services, _resourceGraphBuilder, _options, loggerFactory);
+            _serviceDiscoveryFacade = new ServiceDiscoveryFacade(_services, _resourceGraphBuilder, loggerFactory);
         }
 
         /// <summary>

src/JsonApiDotNetCore/Configuration/ResourceGraph.cs

@@ -47,133 +47,110 @@ public ResourceContext GetResourceContext(Type resourceType)
                 : _resources.SingleOrDefault(resourceContext => resourceContext.ResourceType == resourceType);
         }
 
-        /// <inheritdoc />
-        public ResourceContext GetResourceContext<TResource>()
-            where TResource : class, IIdentifiable
+        private bool IsLazyLoadingProxyForResourceType(Type resourceType)
         {
-            return GetResourceContext(typeof(TResource));
+            return ProxyTargetAccessorType?.IsAssignableFrom(resourceType) ?? false;
         }
 
         /// <inheritdoc />
-        public IReadOnlyCollection<ResourceFieldAttribute> GetFields<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        public ResourceContext GetResourceContext<TResource>()
             where TResource : class, IIdentifiable
         {
-            return Getter(selector);
+            return GetResourceContext(typeof(TResource));
         }
 
         /// <inheritdoc />
-        public IReadOnlyCollection<AttrAttribute> GetAttributes<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        public IReadOnlyCollection<ResourceFieldAttribute> GetFields<TResource>(Expression<Func<TResource, dynamic>> selector)
             where TResource : class, IIdentifiable
         {
-            return Getter(selector, FieldFilterType.Attribute).Cast<AttrAttribute>().ToArray();
+            ArgumentGuard.NotNull(selector, nameof(selector));
+
+            return FilterFields<TResource, ResourceFieldAttribute>(selector);
         }
 
         /// <inheritdoc />
-        public IReadOnlyCollection<RelationshipAttribute> GetRelationships<TResource>(Expression<Func<TResource, dynamic>> selector = null)
+        public IReadOnlyCollection<AttrAttribute> GetAttributes<TResource>(Expression<Func<TResource, dynamic>> selector)
             where TResource : class, IIdentifiable
         {
-            return Getter(selector, FieldFilterType.Relationship).Cast<RelationshipAttribute>().ToArray();
+            ArgumentGuard.NotNull(selector, nameof(selector));
+
+            return FilterFields<TResource, AttrAttribute>(selector);
         }
 
         /// <inheritdoc />
-        public IReadOnlyCollection<ResourceFieldAttribute> GetFields(Type type)
+        public IReadOnlyCollection<RelationshipAttribute> GetRelationships<TResource>(Expression<Func<TResource, dynamic>> selector)
+            where TResource : class, IIdentifiable
         {
-            ArgumentGuard.NotNull(type, nameof(type));
+            ArgumentGuard.NotNull(selector, nameof(selector));
 
-            return GetResourceContext(type).Fields;
+            return FilterFields<TResource, RelationshipAttribute>(selector);
         }
 
-        /// <inheritdoc />
-        public IReadOnlyCollection<AttrAttribute> GetAttributes(Type type)
+        private IReadOnlyCollection<TField> FilterFields<TResource, TField>(Expression<Func<TResource, dynamic>> selector)
+            where TResource : class, IIdentifiable
+            where TField : ResourceFieldAttribute
         {
-            ArgumentGuard.NotNull(type, nameof(type));
+            IReadOnlyCollection<TField> source = GetFieldsOfType<TResource, TField>();
+            var matches = new List<TField>();
 
-            return GetResourceContext(type).Attributes;
-        }
+            foreach (string memberName in ToMemberNames(selector))
+            {
+                TField matchingField = source.FirstOrDefault(field => field.Property.Name == memberName);
 
-        /// <inheritdoc />
-        public IReadOnlyCollection<RelationshipAttribute> GetRelationships(Type type)
-        {
-            ArgumentGuard.NotNull(type, nameof(type));
+                if (matchingField == null)
+                {
+                    throw new ArgumentException($"Member '{memberName}' is not exposed as a JSON:API field.");
+                }
 
-            return GetResourceContext(type).Relationships;
+                matches.Add(matchingField);
+            }
+
+            return matches;
         }
 
-        private IReadOnlyCollection<ResourceFieldAttribute> Getter<TResource>(Expression<Func<TResource, dynamic>> selector = null,
-            FieldFilterType type = FieldFilterType.None)
-            where TResource : class, IIdentifiable
+        private IReadOnlyCollection<TKind> GetFieldsOfType<TResource, TKind>()
+            where TKind : ResourceFieldAttribute
         {
-            IReadOnlyCollection<ResourceFieldAttribute> available;
+            ResourceContext resourceContext = GetResourceContext(typeof(TResource));
 
-            if (type == FieldFilterType.Attribute)
-            {
-                available = GetResourceContext(typeof(TResource)).Attributes;
-            }
-            else if (type == FieldFilterType.Relationship)
-            {
-                available = GetResourceContext(typeof(TResource)).Relationships;
-            }
-            else
+            if (typeof(TKind) == typeof(AttrAttribute))
             {
-                available = GetResourceContext(typeof(TResource)).Fields;
+                return (IReadOnlyCollection<TKind>)resourceContext.Attributes;
             }
 
-            if (selector == null)
+            if (typeof(TKind) == typeof(RelationshipAttribute))
             {
-                return available;
+                return (IReadOnlyCollection<TKind>)resourceContext.Relationships;
             }
 
-            var targeted = new List<ResourceFieldAttribute>();
+            return (IReadOnlyCollection<TKind>)resourceContext.Fields;
+        }
 
+        private IEnumerable<string> ToMemberNames<TResource>(Expression<Func<TResource, dynamic>> selector)
+        {
             Expression selectorBody = RemoveConvert(selector.Body);
 
             if (selectorBody is MemberExpression memberExpression)
             {
                 // model => model.Field1
-                try
-                {
-                    targeted.Add(available.Single(field => field.Property.Name == memberExpression.Member.Name));
-                    return targeted;
-                }
-                catch (InvalidOperationException)
-                {
-                    ThrowNotExposedError(memberExpression.Member.Name, type);
-                }
-            }
 
-            if (selectorBody is NewExpression newExpression)
+                yield return memberExpression.Member.Name;
+            }
+            else if (selectorBody is NewExpression newExpression)
             {
                 // model => new { model.Field1, model.Field2 }
-                string memberName = null;
 
-                try
-                {
-                    if (newExpression.Members == null)
-                    {
-                        return targeted;
-                    }
-
-                    foreach (MemberInfo member in newExpression.Members)
-                    {
-                        memberName = member.Name;
-                        targeted.Add(available.Single(field => field.Property.Name == memberName));
-                    }
-
-                    return targeted;
-                }
-                catch (InvalidOperationException)
+                foreach (MemberInfo member in newExpression.Members ?? Enumerable.Empty<MemberInfo>())
                 {
-                    ThrowNotExposedError(memberName, type);
+                    yield return member.Name;
                 }
             }
-
-            throw new ArgumentException($"The expression '{selector}' should select a single property or select multiple properties into an anonymous type. " +
-                "For example: 'article => article.Title' or 'article => new { article.Title, article.PageCount }'.");
-        }
-
-        private bool IsLazyLoadingProxyForResourceType(Type resourceType)
-        {
-            return ProxyTargetAccessorType?.IsAssignableFrom(resourceType) ?? false;
+            else
+            {
+                throw new ArgumentException(
+                    $"The expression '{selector}' should select a single property or select multiple properties into an anonymous type. " +
+                    "For example: 'article => article.Title' or 'article => new { article.Title, article.PageCount }'.");
+            }
         }
 
         private static Expression RemoveConvert(Expression expression)
@@ -192,17 +169,5 @@ private static Expression RemoveConvert(Expression expression)
                 }
             }
         }
-
-        private void ThrowNotExposedError(string memberName, FieldFilterType type)
-        {
-            throw new ArgumentException($"{memberName} is not a JSON:API exposed {type:g}.");
-        }
-
-        private enum FieldFilterType
-        {
-            None,
-            Attribute,
-            Relationship
-        }
     }
 }

src/JsonApiDotNetCore/Configuration/ResourceGraphBuilder.cs

@@ -202,26 +202,6 @@ private IReadOnlyCollection<RelationshipAttribute> GetRelationships(Type resourc
             return attributes;
         }
 
-        private Type TryGetThroughType(PropertyInfo throughProperty)
-        {
-            if (throughProperty.PropertyType.IsGenericType)
-            {
-                Type[] typeArguments = throughProperty.PropertyType.GetGenericArguments();
-
-                if (typeArguments.Length == 1)
-                {
-                    Type constructedThroughType = typeof(ICollection<>).MakeGenericType(typeArguments[0]);
-
-                    if (throughProperty.PropertyType.IsOrImplementsInterface(constructedThroughType))
-                    {
-                        return typeArguments[0];
-                    }
-                }
-            }
-
-            return null;
-        }
-
         private Type GetRelationshipType(RelationshipAttribute relationship, PropertyInfo property)
         {
             ArgumentGuard.NotNull(relationship, nameof(relationship));

src/JsonApiDotNetCore/Configuration/ServiceDiscoveryFacade.cs

@@ -66,22 +66,18 @@ public class ServiceDiscoveryFacade
         private readonly ILogger<ServiceDiscoveryFacade> _logger;
         private readonly IServiceCollection _services;
         private readonly ResourceGraphBuilder _resourceGraphBuilder;
-        private readonly IJsonApiOptions _options;
         private readonly ResourceDescriptorAssemblyCache _assemblyCache = new();
         private readonly TypeLocator _typeLocator = new();
 
-        public ServiceDiscoveryFacade(IServiceCollection services, ResourceGraphBuilder resourceGraphBuilder, IJsonApiOptions options,
-            ILoggerFactory loggerFactory)
+        public ServiceDiscoveryFacade(IServiceCollection services, ResourceGraphBuilder resourceGraphBuilder, ILoggerFactory loggerFactory)
         {
             ArgumentGuard.NotNull(services, nameof(services));
             ArgumentGuard.NotNull(resourceGraphBuilder, nameof(resourceGraphBuilder));
             ArgumentGuard.NotNull(loggerFactory, nameof(loggerFactory));
-            ArgumentGuard.NotNull(options, nameof(options));
 
             _logger = loggerFactory.CreateLogger<ServiceDiscoveryFacade>();
             _services = services;
             _resourceGraphBuilder = resourceGraphBuilder;
-            _options = options;
         }
 
         /// <summary>

src/JsonApiDotNetCore/Repositories/EntityFrameworkCoreRepository.cs

@@ -314,7 +314,7 @@ public virtual async Task DeleteAsync(TId id, CancellationToken cancellationToke
             using var collector = new PlaceholderResourceCollector(_resourceFactory, _dbContext);
             TResource resource = collector.CreateForId<TResource, TId>(id);
 
-            foreach (RelationshipAttribute relationship in _resourceGraph.GetRelationships<TResource>())
+            foreach (RelationshipAttribute relationship in _resourceGraph.GetResourceContext<TResource>().Relationships)
             {
                 // Loads the data of the relationship, if in EF Core it is configured in such a way that loading the related
                 // entities into memory is required for successfully executing the selected deletion behavior.

src/JsonApiDotNetCore/Resources/Annotations/RelationshipAttribute.cs

@@ -70,7 +70,7 @@ public abstract class RelationshipAttribute : ResourceFieldAttribute
         /// <summary>
         /// Gets the value of the resource property this attribute was declared on.
         /// </summary>
-        public virtual object GetValue(object resource)
+        public object GetValue(object resource)
         {
             ArgumentGuard.NotNull(resource, nameof(resource));
 
@@ -80,7 +80,7 @@ public virtual object GetValue(object resource)
         /// <summary>
         /// Sets the value of the resource property this attribute was declared on.
         /// </summary>
-        public virtual void SetValue(object resource, object newValue)
+        public void SetValue(object resource, object newValue)
         {
             ArgumentGuard.NotNull(resource, nameof(resource));
 

src/JsonApiDotNetCore/Serialization/Client/Internal/IRequestSerializer.cs

@@ -13,14 +13,14 @@ namespace JsonApiDotNetCore.Serialization.Client.Internal
     public interface IRequestSerializer
     {
         /// <summary>
-        /// Sets the attributes that will be included in the serialized request body. You can use <see cref="IResourceGraph.GetAttributes{TResource}" /> to
-        /// conveniently access the desired <see cref="AttrAttribute" /> instances.
+        /// Sets the attributes that will be included in the serialized request body. You can use <see cref="IResourceContextProvider.GetResourceContext{T}()" />
+        /// to conveniently access the desired <see cref="AttrAttribute" /> instances.
         /// </summary>
         public IReadOnlyCollection<AttrAttribute> AttributesToSerialize { get; set; }
 
         /// <summary>
-        /// Sets the relationships that will be included in the serialized request body. You can use <see cref="IResourceGraph.GetRelationships" /> to
-        /// conveniently access the desired <see cref="RelationshipAttribute" /> instances.
+        /// Sets the relationships that will be included in the serialized request body. You can use
+        /// <see cref="IResourceContextProvider.GetResourceContext{T}()" /> to conveniently access the desired <see cref="RelationshipAttribute" /> instances.
         /// </summary>
         public IReadOnlyCollection<RelationshipAttribute> RelationshipsToSerialize { get; set; }
 

src/JsonApiDotNetCore/Serialization/Client/Internal/RequestSerializer.cs

@@ -93,7 +93,8 @@ private IReadOnlyCollection<AttrAttribute> GetAttributesToSerialize(IIdentifiabl
 
             if (AttributesToSerialize == null)
             {
-                return _resourceGraph.GetAttributes(currentResourceType);
+                ResourceContext resourceContext = _resourceGraph.GetResourceContext(currentResourceType);
+                return resourceContext.Attributes;
             }
 
             return AttributesToSerialize;