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Chris Santero
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add materializer for mapping entities to DTOs
1 parent 4d0de76 commit bf14fe0

4 files changed

Lines changed: 243 additions & 1 deletion

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‎JSONAPI.EntityFramework/Http/EntityFrameworkDocumentMaterializer.cs‎

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@@ -63,6 +63,12 @@ public virtual Task<IResourceCollectionDocument> GetRecords(HttpRequestMessage r
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return _queryableResourceCollectionDocumentBuilder.BuildDocument(query, request, cancellationToken);
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}
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public Task<IResourceCollectionDocument> GetRecordsMatchingExpression(Expression<Func<T, bool>> filter, HttpRequestMessage request, CancellationToken cancellationToken)
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{
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var query = _dbContext.Set<T>().AsQueryable().Where(filter);
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return _queryableResourceCollectionDocumentBuilder.BuildDocument(query, request, cancellationToken);
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}
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public virtual async Task<ISingleResourceDocument> GetRecordById(string id, HttpRequestMessage request, CancellationToken cancellationToken)
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{
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var apiBaseUrl = GetBaseUrlFromRequest(request);

‎JSONAPI/Http/IDocumentMaterializer.cs‎

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@@ -1,4 +1,6 @@
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using System.Net.Http;
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using System;
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using System.Linq.Expressions;
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using System.Net.Http;
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using System.Threading;
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using System.Threading.Tasks;
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using JSONAPI.Documents;
@@ -16,6 +18,11 @@ public interface IDocumentMaterializer<T> where T : class
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/// </summary>
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Task<IResourceCollectionDocument> GetRecords(HttpRequestMessage request, CancellationToken cancellationToken);
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/// <summary>
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/// Returns a document containing records matching the provided lambda expression.
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/// </summary>
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Task<IResourceCollectionDocument> GetRecordsMatchingExpression(Expression<Func<T, bool>> filter, HttpRequestMessage request, CancellationToken cancellationToken);
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/// <summary>
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/// Returns a document with the resource identified by the given ID.
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/// </summary>

‎JSONAPI/Http/MappedDocumentMaterializer.cs‎

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@@ -0,0 +1,228 @@
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using System;
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using System.Collections.Concurrent;
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using System.Collections.Generic;
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using System.Linq;
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using System.Linq.Expressions;
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using System.Net.Http;
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using System.Reflection;
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using System.Threading;
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using System.Threading.Tasks;
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using JSONAPI.Core;
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using JSONAPI.Documents;
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using JSONAPI.Documents.Builders;
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using JSONAPI.QueryableTransformers;
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namespace JSONAPI.Http
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{
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/// <summary>
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/// Document materializer for mapping from a database entity to a data transfer object.
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/// </summary>
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/// <typeparam name="TEntity"></typeparam>
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/// <typeparam name="TDto"></typeparam>
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public abstract class MappedDocumentMaterializer<TEntity, TDto> : IDocumentMaterializer<TDto> where TDto : class
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{
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/// <summary>
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/// Materializes a document for the resources found on the other side of the to-many relationship belonging to the resource.
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/// </summary>
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protected delegate Task<IResourceCollectionDocument> MaterializeDocumentForToManyRelationship(
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TDto resource, HttpRequestMessage request, CancellationToken cancellationToken);
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/// <summary>
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/// Materializes a document for the resources found on the other side of the to-one relationship belonging to the resource.
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/// </summary>
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protected delegate Task<ISingleResourceDocument> MaterializeDocumentForToOneRelationship(
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TDto resource, HttpRequestMessage request, CancellationToken cancellationToken);
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private readonly IQueryableResourceCollectionDocumentBuilder _queryableResourceCollectionDocumentBuilder;
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private readonly IBaseUrlService _baseUrlService;
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private readonly ISingleResourceDocumentBuilder _singleResourceDocumentBuilder;
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private readonly IQueryableEnumerationTransformer _queryableEnumerationTransformer;
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private readonly IResourceTypeRegistry _resourceTypeRegistry;
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private readonly IDictionary<ResourceTypeRelationship, MaterializeDocumentForToManyRelationship> _toManyRelatedResourceMaterializers;
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private readonly IDictionary<ResourceTypeRelationship, MaterializeDocumentForToOneRelationship> _toOneRelatedResourceMaterializers;
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/// <summary>
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/// Gets a query returning all entities for this endpoint
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/// </summary>
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/// <returns></returns>
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protected abstract IQueryable<TEntity> GetQuery();
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protected abstract IQueryable<TEntity> GetByIdQuery(string id);
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protected abstract IQueryable<TDto> GetMappedQuery(IQueryable<TEntity> entityQuery, Expression<Func<TDto, object>>[] propertiesToInclude);
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protected MappedDocumentMaterializer(
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IQueryableResourceCollectionDocumentBuilder queryableResourceCollectionDocumentBuilder,
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IBaseUrlService baseUrlService,
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ISingleResourceDocumentBuilder singleResourceDocumentBuilder,
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IQueryableEnumerationTransformer queryableEnumerationTransformer,
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IResourceTypeRegistry resourceTypeRegistry)
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{
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_queryableResourceCollectionDocumentBuilder = queryableResourceCollectionDocumentBuilder;
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_baseUrlService = baseUrlService;
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_singleResourceDocumentBuilder = singleResourceDocumentBuilder;
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_queryableEnumerationTransformer = queryableEnumerationTransformer;
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_resourceTypeRegistry = resourceTypeRegistry;
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_toManyRelatedResourceMaterializers =
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new ConcurrentDictionary<ResourceTypeRelationship, MaterializeDocumentForToManyRelationship>();
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_toOneRelatedResourceMaterializers =
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new ConcurrentDictionary<ResourceTypeRelationship, MaterializeDocumentForToOneRelationship>();
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}
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public async Task<IResourceCollectionDocument> GetRecords(HttpRequestMessage request, CancellationToken cancellationToken)
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{
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return await GetRecordsMatchingExpression(m => true, request, cancellationToken);
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}
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public async Task<IResourceCollectionDocument> GetRecordsMatchingExpression(Expression<Func<TDto, bool>> filter, HttpRequestMessage request, CancellationToken cancellationToken)
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{
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var entityQuery = GetQuery();
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var includePaths = GetIncludePathsForQuery() ?? new Expression<Func<TDto, object>>[] { };
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var jsonApiPaths = includePaths.Select(ConvertToJsonKeyPath).ToArray();
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var mappedQuery = GetMappedQuery(entityQuery, includePaths);
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return await _queryableResourceCollectionDocumentBuilder.BuildDocument(mappedQuery, request, cancellationToken, jsonApiPaths);
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}
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public async Task<ISingleResourceDocument> GetRecordById(string id, HttpRequestMessage request, CancellationToken cancellationToken)
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{
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var entityQuery = GetByIdQuery(id);
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var includePaths = GetIncludePathsForSingleResource() ?? new Expression<Func<TDto, object>>[] { };
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var jsonApiPaths = includePaths.Select(ConvertToJsonKeyPath).ToArray();
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var mappedQuery = GetMappedQuery(entityQuery, includePaths);
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var primaryResource = await _queryableEnumerationTransformer.FirstOrDefault(mappedQuery, cancellationToken);
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if (primaryResource == null) throw JsonApiException.CreateForNotFound(string.Format("No record exists with ID {0} for the requested type.", id));
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var baseUrl = _baseUrlService.GetBaseUrl(request);
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return _singleResourceDocumentBuilder.BuildDocument(primaryResource, baseUrl, jsonApiPaths);
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}
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public async Task<IJsonApiDocument> GetRelated(string id, string relationshipKey, HttpRequestMessage request, CancellationToken cancellationToken)
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{
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var registration = _resourceTypeRegistry.GetRegistrationForType(typeof(TDto));
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var primaryEntityQuery = GetByIdQuery(id);
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var mappedQuery = GetMappedQuery(primaryEntityQuery, null);
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var primaryResource = await _queryableEnumerationTransformer.FirstOrDefault(mappedQuery, cancellationToken);
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if (primaryResource == null)
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{
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var dtoRegistration = _resourceTypeRegistry.GetRegistrationForType(typeof(TDto));
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throw JsonApiException.CreateForNotFound(string.Format(
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"No resource of type `{0}` exists with id `{1}`.",
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dtoRegistration.ResourceTypeName, id));
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}
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var relationship = (ResourceTypeRelationship)registration.GetFieldByName(relationshipKey);
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if (relationship == null)
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throw JsonApiException.CreateForNotFound(string.Format("No relationship `{0}` exists for the resource with type `{1}` and id `{2}`.",
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relationshipKey, registration.ResourceTypeName, id));
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if (relationship.IsToMany)
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{
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MaterializeDocumentForToManyRelationship documentFactory;
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if (!_toManyRelatedResourceMaterializers.TryGetValue(relationship, out documentFactory))
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{
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documentFactory = GetMaterializerForToManyRelatedResource(relationship);
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_toManyRelatedResourceMaterializers.Add(relationship, documentFactory);
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}
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return await documentFactory(primaryResource, request, cancellationToken);
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}
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else
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{
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MaterializeDocumentForToOneRelationship relatedResourceMaterializer;
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if (!_toOneRelatedResourceMaterializers.TryGetValue(relationship, out relatedResourceMaterializer))
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{
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relatedResourceMaterializer = GetMaterializerForToOneRelatedResource(relationship);
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_toOneRelatedResourceMaterializers.Add(relationship, relatedResourceMaterializer);
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}
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return await relatedResourceMaterializer(primaryResource, request, cancellationToken);
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}
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}
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public Task<ISingleResourceDocument> CreateRecord(ISingleResourceDocument requestDocument, HttpRequestMessage request,
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CancellationToken cancellationToken)
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{
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throw new NotImplementedException();
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}
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public Task<ISingleResourceDocument> UpdateRecord(string id, ISingleResourceDocument requestDocument, HttpRequestMessage request,
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CancellationToken cancellationToken)
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{
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throw new NotImplementedException();
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}
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public Task<IJsonApiDocument> DeleteRecord(string id, CancellationToken cancellationToken)
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{
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throw new NotImplementedException();
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}
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/// <summary>
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/// Returns a list of property paths to be included when constructing a query for this resource type
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/// </summary>
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protected virtual Expression<Func<TDto, object>>[] GetIncludePathsForQuery()
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{
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return null;
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}
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/// <summary>
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/// Returns a list of property paths to be included when returning a single resource of this resource type
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/// </summary>
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protected virtual Expression<Func<TDto, object>>[] GetIncludePathsForSingleResource()
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{
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return null;
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}
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/// <summary>
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/// Returns a materialization delegate to handle related resource requests for a to-many relationship
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/// </summary>
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protected abstract MaterializeDocumentForToManyRelationship GetMaterializerForToManyRelatedResource(ResourceTypeRelationship relationship);
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/// <summary>
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/// Returns a materialization delegate to handle related resource requests for a to-one relationship
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/// </summary>
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protected abstract MaterializeDocumentForToOneRelationship GetMaterializerForToOneRelatedResource(ResourceTypeRelationship relationship);
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private string ConvertToJsonKeyPath(Expression<Func<TDto, object>> expression)
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{
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var visitor = new PathVisitor(_resourceTypeRegistry);
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visitor.Visit(expression);
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return visitor.Path;
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}
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private class PathVisitor : ExpressionVisitor
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{
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private readonly IResourceTypeRegistry _resourceTypeRegistry;
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public PathVisitor(IResourceTypeRegistry resourceTypeRegistry)
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{
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_resourceTypeRegistry = resourceTypeRegistry;
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}
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private readonly Stack<string> _segments = new Stack<string>();
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public string Path { get { return string.Join(".", _segments.ToArray()); } }
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protected override Expression VisitMethodCall(MethodCallExpression node)
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{
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if (node.Method.Name == "Select")
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{
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Visit(node.Arguments[1]);
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Visit(node.Arguments[0]);
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}
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return node;
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}
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protected override Expression VisitMember(MemberExpression node)
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{
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var property = node.Member as PropertyInfo;
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if (property == null) return node;
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var registration = _resourceTypeRegistry.GetRegistrationForType(property.DeclaringType);
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if (registration == null || registration.Relationships == null) return node;
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var relationship = registration.Relationships.FirstOrDefault(r => r.Property == property);
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if (relationship == null) return node;
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_segments.Push(relationship.JsonKey);
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return base.VisitMember(node);
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}
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}
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}
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}

‎JSONAPI/JSONAPI.csproj‎

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<Reference Include="System.Xml" />
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</ItemGroup>
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<ItemGroup>
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<Compile Include="Http\MappedDocumentMaterializer.cs" />
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<Compile Include="QueryableTransformers\DefaultFilteringTransformer.cs" />
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<Compile Include="QueryableTransformers\DefaultPaginationTransformer.cs" />
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<Compile Include="QueryableTransformers\DefaultPaginationTransformResult.cs" />

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