Resource inheritance: write endpoints

Author: Bart Koelman

Diff for: benchmarks/Serialization/SerializationBenchmarkBase.cs

@@ -180,9 +180,9 @@ public Task OnSetToManyRelationshipAsync<TResource>(TResource leftResource, HasM
             return Task.CompletedTask;
         }
 
-        public Task OnAddToRelationshipAsync<TResource, TId>(TId leftResourceId, HasManyAttribute hasManyRelationship, ISet<IIdentifiable> rightResourceIds,
+        public Task OnAddToRelationshipAsync<TResource>(TResource leftResource, HasManyAttribute hasManyRelationship, ISet<IIdentifiable> rightResourceIds,
             CancellationToken cancellationToken)
-            where TResource : class, IIdentifiable<TId>
+            where TResource : class, IIdentifiable
         {
             return Task.CompletedTask;
         }

Diff for: src/JsonApiDotNetCore.Annotations/Configuration/ResourceType.cs

@@ -206,6 +206,43 @@ public IReadOnlySet<ResourceType> GetAllConcreteDerivedTypes()
         return _lazyAllConcreteDerivedTypes.Value;
     }
 
+    /// <summary>
+    /// Searches the tree of derived types to find a match for the specified <paramref name="clrType" />.
+    /// </summary>
+    public ResourceType GetTypeOrDerived(Type clrType)
+    {
+        ArgumentGuard.NotNull(clrType, nameof(clrType));
+
+        ResourceType? derivedType = FindTypeOrDerived(this, clrType);
+
+        if (derivedType == null)
+        {
+            throw new InvalidOperationException($"Resource type '{PublicName}' is not a base type of '{clrType}'.");
+        }
+
+        return derivedType;
+    }
+
+    private static ResourceType? FindTypeOrDerived(ResourceType type, Type clrType)
+    {
+        if (type.ClrType == clrType)
+        {
+            return type;
+        }
+
+        foreach (ResourceType derivedType in type.DirectlyDerivedTypes)
+        {
+            ResourceType? matchingType = FindTypeOrDerived(derivedType, clrType);
+
+            if (matchingType != null)
+            {
+                return matchingType;
+            }
+        }
+
+        return null;
+    }
+
     internal IReadOnlySet<AttrAttribute> GetAttributesInTypeOrDerived(string publicName)
     {
         return GetAttributesInTypeOrDerived(this, publicName);
@@ -261,6 +298,11 @@ private static IReadOnlySet<RelationshipAttribute> GetRelationshipsInTypeOrDeriv
         return relationshipsInDerivedTypes;
     }
 
+    internal bool IsPartOfTypeHierarchy()
+    {
+        return BaseType != null || DirectlyDerivedTypes.Any();
+    }
+
     public override string ToString()
     {
         return PublicName;

Diff for: src/JsonApiDotNetCore/Queries/Internal/QueryLayerComposer.cs

@@ -422,7 +422,7 @@ public QueryLayer ComposeForGetRelationshipRightIds(RelationshipAttribute relati
 
         AttrAttribute rightIdAttribute = GetIdAttribute(relationship.RightType);
 
-        object[] typedIds = rightResourceIds.Select(resource => resource.GetTypedId()).ToArray();
+        HashSet<object> typedIds = rightResourceIds.Select(resource => resource.GetTypedId()).ToHashSet();
 
         FilterExpression? baseFilter = GetFilter(Array.Empty<QueryExpression>(), relationship.RightType);
         FilterExpression? filter = CreateFilterByIds(typedIds, rightIdAttribute, baseFilter);
@@ -447,7 +447,7 @@ public QueryLayer ComposeForHasMany<TId>(HasManyAttribute hasManyRelationship, T
 
         AttrAttribute leftIdAttribute = GetIdAttribute(hasManyRelationship.LeftType);
         AttrAttribute rightIdAttribute = GetIdAttribute(hasManyRelationship.RightType);
-        object[] rightTypedIds = rightResourceIds.Select(resource => resource.GetTypedId()).ToArray();
+        HashSet<object> rightTypedIds = rightResourceIds.Select(resource => resource.GetTypedId()).ToHashSet();
 
         FilterExpression? leftFilter = CreateFilterByIds(leftId.AsArray(), leftIdAttribute, null);
         FilterExpression? rightFilter = CreateFilterByIds(rightTypedIds, rightIdAttribute, null);

Diff for: src/JsonApiDotNetCore/Repositories/EntityFrameworkCoreRepository.cs

@@ -155,14 +155,15 @@ protected virtual IQueryable<TResource> GetAll()
     }
 
     /// <inheritdoc />
-    public virtual Task<TResource> GetForCreateAsync(TId id, CancellationToken cancellationToken)
+    public virtual Task<TResource> GetForCreateAsync(Type resourceClrType, TId id, CancellationToken cancellationToken)
     {
         _traceWriter.LogMethodStart(new
         {
+            resourceClrType,
             id
         });
 
-        var resource = _resourceFactory.CreateInstance<TResource>();
+        var resource = (TResource)_resourceFactory.CreateInstance(resourceClrType);
         resource.Id = id;
 
         return Task.FromResult(resource);
@@ -305,18 +306,19 @@ protected void AssertIsNotClearingRequiredToOneRelationship(RelationshipAttribut
     }
 
     /// <inheritdoc />
-    public virtual async Task DeleteAsync(TId id, CancellationToken cancellationToken)
+    public virtual async Task DeleteAsync(TResource? resourceFromDatabase, TId id, CancellationToken cancellationToken)
     {
         _traceWriter.LogMethodStart(new
         {
+            resourceFromDatabase,
             id
         });
 
         using IDisposable _ = CodeTimingSessionManager.Current.Measure("Repository - Delete resource");
 
         // This enables OnWritingAsync() to fetch the resource, which adds it to the change tracker.
         // If so, we'll reuse the tracked resource instead of this placeholder resource.
-        var placeholderResource = _resourceFactory.CreateInstance<TResource>();
+        TResource placeholderResource = resourceFromDatabase ?? _resourceFactory.CreateInstance<TResource>();
         placeholderResource.Id = id;
 
         await _resourceDefinitionAccessor.OnWritingAsync(placeholderResource, WriteOperationKind.DeleteResource, cancellationToken);
@@ -413,10 +415,12 @@ public virtual async Task SetRelationshipAsync(TResource leftResource, object? r
     }
 
     /// <inheritdoc />
-    public virtual async Task AddToToManyRelationshipAsync(TId leftId, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken)
+    public virtual async Task AddToToManyRelationshipAsync(TResource? leftResource, TId leftId, ISet<IIdentifiable> rightResourceIds,
+        CancellationToken cancellationToken)
     {
         _traceWriter.LogMethodStart(new
         {
+            leftResource,
             leftId,
             rightResourceIds
         });
@@ -427,25 +431,53 @@ public virtual async Task AddToToManyRelationshipAsync(TId leftId, ISet<IIdentif
 
         var relationship = (HasManyAttribute)_targetedFields.Relationships.Single();
 
-        await _resourceDefinitionAccessor.OnAddToRelationshipAsync<TResource, TId>(leftId, relationship, rightResourceIds, cancellationToken);
+        // This enables OnAddToRelationshipAsync() or OnWritingAsync() to fetch the resource, which adds it to the change tracker.
+        // If so, we'll reuse the tracked resource instead of this placeholder resource.
+        TResource leftPlaceholderResource = leftResource ?? _resourceFactory.CreateInstance<TResource>();
+        leftPlaceholderResource.Id = leftId;
+
+        await _resourceDefinitionAccessor.OnAddToRelationshipAsync(leftPlaceholderResource, relationship, rightResourceIds, cancellationToken);
 
         if (rightResourceIds.Any())
         {
-            var leftPlaceholderResource = _resourceFactory.CreateInstance<TResource>();
-            leftPlaceholderResource.Id = leftId;
-
             var leftResourceTracked = (TResource)_dbContext.GetTrackedOrAttach(leftPlaceholderResource);
+            IEnumerable rightValueToStore = GetRightValueToStoreForAddToToMany(leftResourceTracked, relationship, rightResourceIds);
 
-            await UpdateRelationshipAsync(relationship, leftResourceTracked, rightResourceIds, cancellationToken);
+            await UpdateRelationshipAsync(relationship, leftResourceTracked, rightValueToStore, cancellationToken);
 
             await _resourceDefinitionAccessor.OnWritingAsync(leftResourceTracked, WriteOperationKind.AddToRelationship, cancellationToken);
+            leftResourceTracked = (TResource)_dbContext.GetTrackedOrAttach(leftResourceTracked);
 
             await SaveChangesAsync(cancellationToken);
 
             await _resourceDefinitionAccessor.OnWriteSucceededAsync(leftResourceTracked, WriteOperationKind.AddToRelationship, cancellationToken);
         }
     }
 
+    private IEnumerable GetRightValueToStoreForAddToToMany(TResource leftResource, HasManyAttribute relationship, ISet<IIdentifiable> rightResourceIdsToAdd)
+    {
+        object? rightValueStored = relationship.GetValue(leftResource);
+
+        // @formatter:wrap_chained_method_calls chop_always
+        // @formatter:keep_existing_linebreaks true
+
+        HashSet<IIdentifiable> rightResourceIdsStored = _collectionConverter
+            .ExtractResources(rightValueStored)
+            .Select(rightResource => _dbContext.GetTrackedOrAttach(rightResource))
+            .ToHashSet(IdentifiableComparer.Instance);
+
+        // @formatter:keep_existing_linebreaks restore
+        // @formatter:wrap_chained_method_calls restore
+
+        if (rightResourceIdsStored.Any())
+        {
+            rightResourceIdsStored.AddRange(rightResourceIdsToAdd);
+            return rightResourceIdsStored;
+        }
+
+        return rightResourceIdsToAdd;
+    }
+
     /// <inheritdoc />
     public virtual async Task RemoveFromToManyRelationshipAsync(TResource leftResource, ISet<IIdentifiable> rightResourceIds,
         CancellationToken cancellationToken)
@@ -473,7 +505,7 @@ public virtual async Task RemoveFromToManyRelationshipAsync(TResource leftResour
             // Make Entity Framework Core believe any additional resources added from ResourceDefinition already exist in database.
             IIdentifiable[] extraResourceIdsToRemove = rightResourceIdsToRemove.Where(rightId => !rightResourceIds.Contains(rightId)).ToArray();
 
-            object? rightValueStored = relationship.GetValue(leftResource);
+            object? rightValueStored = relationship.GetValue(leftResourceTracked);
 
             // @formatter:wrap_chained_method_calls chop_always
             // @formatter:keep_existing_linebreaks true
@@ -488,9 +520,9 @@ public virtual async Task RemoveFromToManyRelationshipAsync(TResource leftResour
             // @formatter:wrap_chained_method_calls restore
 
             rightValueStored = _collectionConverter.CopyToTypedCollection(rightResourceIdsStored, relationship.Property.PropertyType);
-            relationship.SetValue(leftResource, rightValueStored);
+            relationship.SetValue(leftResourceTracked, rightValueStored);
 
-            MarkRelationshipAsLoaded(leftResource, relationship);
+            MarkRelationshipAsLoaded(leftResourceTracked, relationship);
 
             HashSet<IIdentifiable> rightResourceIdsToStore = rightResourceIdsStored.ToHashSet(IdentifiableComparer.Instance);
             rightResourceIdsToStore.ExceptWith(rightResourceIdsToRemove);

Diff for: src/JsonApiDotNetCore/Repositories/IResourceRepositoryAccessor.cs

@@ -11,7 +11,7 @@ namespace JsonApiDotNetCore.Repositories;
 public interface IResourceRepositoryAccessor
 {
     /// <summary>
-    /// Invokes <see cref="IResourceReadRepository{TResource,TId}.GetAsync" />.
+    /// Invokes <see cref="IResourceReadRepository{TResource,TId}.GetAsync" /> for the specified resource type.
     /// </summary>
     Task<IReadOnlyCollection<TResource>> GetAsync<TResource>(QueryLayer queryLayer, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;
@@ -27,49 +27,50 @@ Task<IReadOnlyCollection<TResource>> GetAsync<TResource>(QueryLayer queryLayer,
     Task<int> CountAsync(ResourceType resourceType, FilterExpression? filter, CancellationToken cancellationToken);
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.GetForCreateAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.GetForCreateAsync" /> for the specified resource type.
     /// </summary>
-    Task<TResource> GetForCreateAsync<TResource, TId>(TId id, CancellationToken cancellationToken)
+    Task<TResource> GetForCreateAsync<TResource, TId>(Type resourceClrType, TId id, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>;
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.CreateAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.CreateAsync" /> for the specified resource type.
     /// </summary>
     Task CreateAsync<TResource>(TResource resourceFromRequest, TResource resourceForDatabase, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.GetForUpdateAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.GetForUpdateAsync" /> for the specified resource type.
     /// </summary>
     Task<TResource?> GetForUpdateAsync<TResource>(QueryLayer queryLayer, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.UpdateAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.UpdateAsync" /> for the specified resource type.
     /// </summary>
     Task UpdateAsync<TResource>(TResource resourceFromRequest, TResource resourceFromDatabase, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;
 
     /// <summary>
     /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.DeleteAsync" /> for the specified resource type.
     /// </summary>
-    Task DeleteAsync<TResource, TId>(TId id, CancellationToken cancellationToken)
+    Task DeleteAsync<TResource, TId>(TResource? resourceFromDatabase, TId id, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>;
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.SetRelationshipAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.SetRelationshipAsync" /> for the specified resource type.
     /// </summary>
     Task SetRelationshipAsync<TResource>(TResource leftResource, object? rightValue, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;
 
     /// <summary>
     /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.AddToToManyRelationshipAsync" /> for the specified resource type.
     /// </summary>
-    Task AddToToManyRelationshipAsync<TResource, TId>(TId leftId, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken)
+    Task AddToToManyRelationshipAsync<TResource, TId>(TResource? leftResource, TId leftId, ISet<IIdentifiable> rightResourceIds,
+        CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>;
 
     /// <summary>
-    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.RemoveFromToManyRelationshipAsync" />.
+    /// Invokes <see cref="IResourceWriteRepository{TResource,TId}.RemoveFromToManyRelationshipAsync" /> for the specified resource type.
     /// </summary>
     Task RemoveFromToManyRelationshipAsync<TResource>(TResource leftResource, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable;

Diff for: src/JsonApiDotNetCore/Repositories/IResourceWriteRepository.cs

@@ -23,7 +23,7 @@ public interface IResourceWriteRepository<TResource, in TId>
     /// <remarks>
     /// This method can be overridden to assign resource-specific required relationships.
     /// </remarks>
-    Task<TResource> GetForCreateAsync(TId id, CancellationToken cancellationToken);
+    Task<TResource> GetForCreateAsync(Type resourceClrType, TId id, CancellationToken cancellationToken);
 
     /// <summary>
     /// Creates a new resource in the underlying data store.
@@ -43,7 +43,7 @@ public interface IResourceWriteRepository<TResource, in TId>
     /// <summary>
     /// Deletes an existing resource from the underlying data store.
     /// </summary>
-    Task DeleteAsync(TId id, CancellationToken cancellationToken);
+    Task DeleteAsync(TResource? resourceFromDatabase, TId id, CancellationToken cancellationToken);
 
     /// <summary>
     /// Performs a complete replacement of the relationship in the underlying data store.
@@ -53,7 +53,7 @@ public interface IResourceWriteRepository<TResource, in TId>
     /// <summary>
     /// Adds resources to a to-many relationship in the underlying data store.
     /// </summary>
-    Task AddToToManyRelationshipAsync(TId leftId, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken);
+    Task AddToToManyRelationshipAsync(TResource? leftResource, TId leftId, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken);
 
     /// <summary>
     /// Removes resources from a to-many relationship in the underlying data store.

Diff for: src/JsonApiDotNetCore/Repositories/ResourceRepositoryAccessor.cs

@@ -53,11 +53,11 @@ public async Task<int> CountAsync(ResourceType resourceType, FilterExpression? f
     }
 
     /// <inheritdoc />
-    public async Task<TResource> GetForCreateAsync<TResource, TId>(TId id, CancellationToken cancellationToken)
+    public async Task<TResource> GetForCreateAsync<TResource, TId>(Type resourceClrType, TId id, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>
     {
         dynamic repository = GetWriteRepository(typeof(TResource));
-        return await repository.GetForCreateAsync(id, cancellationToken);
+        return await repository.GetForCreateAsync(resourceClrType, id, cancellationToken);
     }
 
     /// <inheritdoc />
@@ -85,11 +85,11 @@ public async Task UpdateAsync<TResource>(TResource resourceFromRequest, TResourc
     }
 
     /// <inheritdoc />
-    public async Task DeleteAsync<TResource, TId>(TId id, CancellationToken cancellationToken)
+    public async Task DeleteAsync<TResource, TId>(TResource? resourceFromDatabase, TId id, CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>
     {
         dynamic repository = GetWriteRepository(typeof(TResource));
-        await repository.DeleteAsync(id, cancellationToken);
+        await repository.DeleteAsync(resourceFromDatabase, id, cancellationToken);
     }
 
     /// <inheritdoc />
@@ -101,11 +101,12 @@ public async Task SetRelationshipAsync<TResource>(TResource leftResource, object
     }
 
     /// <inheritdoc />
-    public async Task AddToToManyRelationshipAsync<TResource, TId>(TId leftId, ISet<IIdentifiable> rightResourceIds, CancellationToken cancellationToken)
+    public async Task AddToToManyRelationshipAsync<TResource, TId>(TResource? leftResource, TId leftId, ISet<IIdentifiable> rightResourceIds,
+        CancellationToken cancellationToken)
         where TResource : class, IIdentifiable<TId>
     {
         dynamic repository = GetWriteRepository(typeof(TResource));
-        await repository.AddToToManyRelationshipAsync(leftId, rightResourceIds, cancellationToken);
+        await repository.AddToToManyRelationshipAsync(leftResource, leftId, rightResourceIds, cancellationToken);
     }
 
     /// <inheritdoc />

Diff for: src/JsonApiDotNetCore/Resources/AbstractResourceWrapper.cs

@@ -0,0 +1,15 @@
+namespace JsonApiDotNetCore.Resources;
+
+/// <inheritdoc cref="IAbstractResourceWrapper" />
+internal sealed class AbstractResourceWrapper<TId> : Identifiable<TId>, IAbstractResourceWrapper
+{
+    /// <inheritdoc />
+    public Type AbstractType { get; }
+
+    public AbstractResourceWrapper(Type abstractType)
+    {
+        ArgumentGuard.NotNull(abstractType, nameof(abstractType));
+
+        AbstractType = abstractType;
+    }
+}

Diff for: src/JsonApiDotNetCore/Resources/IAbstractResourceWrapper.cs

@@ -0,0 +1,12 @@
+namespace JsonApiDotNetCore.Resources;
+
+/// <summary>
+/// Because an instance cannot be created from an abstract resource type, this wrapper is used to preserve that information.
+/// </summary>
+internal interface IAbstractResourceWrapper : IIdentifiable
+{
+    /// <summary>
+    /// The abstract resource type.
+    /// </summary>
+    Type AbstractType { get; }
+}