add overridable controllers

Author: jaredcnance

JsonApiDotNetCore/Configuration/IJsonApiModelConfiguration.cs

@@ -1,13 +1,39 @@
 using System;
 using System.Collections.Generic;
-using AutoMapper;
+using JsonApiDotNetCore.Abstractions;
 
 namespace JsonApiDotNetCore.Configuration
 {
   public interface IJsonApiModelConfiguration
   {
+    /// <summary>
+    /// The database context to use
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    /// <exception cref="ArgumentException"></exception>
     void UseContext<T>();
+
+    /// <summary>
+    /// The request namespace.
+    /// </summary>
+    /// <param name="ns"></param>
+    /// <example>api/v1</example>
     void SetDefaultNamespace(string ns);
-    void DefineResourceMapping(Action<Dictionary<Type,Type>> mapping);
+
+    /// <summary>
+    /// Define explicit mapping of a model to a class that implements IJsonApiResource
+    /// </summary>
+    /// <param name="modelType"></param>
+    /// <param name="resourceType"></param>
+    /// <exception cref="ArgumentException"></exception>
+    void AddResourceMapping(Type modelType, Type resourceType);
+
+    /// <summary>
+    /// Specifies a controller override class for a particular model type.
+    /// </summary>
+    /// <param name="modelType"></param>
+    /// <param name="controllerType"></param>
+    /// <exception cref="ArgumentException"></exception>
+    void UseController(Type modelType, Type controllerType);
   }
 }

JsonApiDotNetCore/Configuration/JsonApiConfigurationBuilder.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Reflection;
+using JsonApiDotNetCore.Routing;
+using Microsoft.EntityFrameworkCore;
+using System.Linq;
+using AutoMapper;
+using JsonApiDotNetCore.Abstractions;
+using JsonApiDotNetCore.Attributes;
+
+namespace JsonApiDotNetCore.Configuration
+{
+  public class JsonApiConfigurationBuilder
+  {
+    private readonly Action<IJsonApiModelConfiguration> _configurationAction;
+    private JsonApiModelConfiguration Config { get; set; }
+
+    public JsonApiConfigurationBuilder(Action<IJsonApiModelConfiguration> configurationAction)
+    {
+      Config = new JsonApiModelConfiguration();
+      _configurationAction = configurationAction;
+    }
+
+    public JsonApiModelConfiguration Build()
+    {
+      Config = new JsonApiModelConfiguration();
+      _configurationAction.Invoke(Config);
+      CheckIsValidConfiguration();
+      LoadModelRoutesFromContext();
+      SetupResourceMaps();
+      return Config;
+    }
+
+    private void CheckIsValidConfiguration()
+    {
+      if (Config.ContextType == null)
+        throw new NullReferenceException("DbContext is not specified");
+    }
+
+    private void LoadModelRoutesFromContext()
+    {
+      // Assumption: all DbSet<> types should be included in the route list
+      var properties = Config.ContextType.GetProperties().ToList();
+
+      properties.ForEach(property =>
+      {
+        if (property.PropertyType.GetTypeInfo().IsGenericType &&
+          property.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>))
+        {
+
+          var modelType = property.PropertyType.GetGenericArguments()[0];
+
+          var route = new RouteDefinition
+          {
+            ModelType = modelType,
+            PathString = RouteBuilder.BuildRoute(Config.Namespace, property.Name),
+            ContextPropertyName = property.Name
+          };
+
+          Config.Routes.Add(route);
+        }
+      });
+    }
+
+    private void SetupResourceMaps()
+    {
+      LoadDefaultResourceMaps();
+      var mapConfiguration = new MapperConfiguration(cfg =>
+      {
+        foreach (var definition in Config.ResourceMapDefinitions)
+        {
+          cfg.CreateMap(definition.Key, definition.Value);
+        }
+      });
+
+      Config.ResourceMapper = mapConfiguration.CreateMapper();
+    }
+
+    private void LoadDefaultResourceMaps()
+    {
+      var resourceAttribute = typeof(JsonApiResourceAttribute);
+      var modelTypes = Assembly.GetEntryAssembly().DefinedTypes.Where(t => t.GetCustomAttributes(resourceAttribute).Count() == 1);
+
+      foreach (var modelType in modelTypes)
+      {
+        var resourceType = ((JsonApiResourceAttribute)modelType.GetCustomAttribute(resourceAttribute)).JsonApiResourceType;
+
+        // do not overwrite custom definitions
+        if(!Config.ResourceMapDefinitions.ContainsKey(modelType.UnderlyingSystemType))
+        {
+          Config.ResourceMapDefinitions.Add(modelType.UnderlyingSystemType, resourceType);
+        }
+      }
+    }
+  }
+}

JsonApiDotNetCore/Configuration/JsonApiModelConfiguration.cs

@@ -3,6 +3,8 @@
 using System.Linq;
 using System.Reflection;
 using AutoMapper;
+using JsonApiDotNetCore.Abstractions;
+using JsonApiDotNetCore.Controllers;
 using JsonApiDotNetCore.JsonApi;
 using JsonApiDotNetCore.Routing;
 using Microsoft.AspNetCore.Http;
@@ -17,58 +19,36 @@ public class JsonApiModelConfiguration : IJsonApiModelConfiguration
     public Type ContextType { get; set; }
     public List<RouteDefinition> Routes = new List<RouteDefinition>();
     public Dictionary<Type, Type>  ResourceMapDefinitions = new Dictionary<Type, Type>();
+    public Dictionary<Type, Type> ControllerOverrides = new Dictionary<Type, Type>();
 
     public void SetDefaultNamespace(string ns)
     {
       Namespace = ns;
     }
 
-    public void DefineResourceMapping(Action<Dictionary<Type,Type>> mapping)
+    // TODO: change to AddResourceMapping(Type, Type)
+    public void AddResourceMapping(Type modelType, Type resourceType)
     {
-      mapping.Invoke(ResourceMapDefinitions);
+      if (!resourceType.GetInterfaces().Contains(typeof(IJsonApiResource)))
+        throw new ArgumentException("Specified type does not implement IJsonApiResource", nameof(resourceType));
 
-      var mapConfiguration = new MapperConfiguration(cfg =>
-      {
-        foreach (var definition in ResourceMapDefinitions)
-        {
-          cfg.CreateMap(definition.Key, definition.Value);
-        }
-      });
-
-      ResourceMapper = mapConfiguration.CreateMapper();
+      ResourceMapDefinitions.Add(modelType, resourceType);
     }
 
-    public void UseContext<T>()
+    public void UseController(Type modelType, Type controllerType)
     {
-      // TODO: assert the context is of type DbContext
-      ContextType = typeof(T);
-      LoadModelRoutesFromContext();
+      if(!controllerType.GetInterfaces().Contains(typeof(IJsonApiController)))
+        throw new ArgumentException("Specified type does not implement IJsonApiController", nameof(controllerType));
+
+      ControllerOverrides[modelType] = controllerType;
     }
 
-    private void LoadModelRoutesFromContext()
+    public void UseContext<T>()
     {
-      // Assumption: all DbSet<> types should be included in the route list
-      var properties = ContextType.GetProperties().ToList();
-
-      properties.ForEach(property =>
-      {
-        if (property.PropertyType.GetTypeInfo().IsGenericType &&
-          property.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>))
-        {
-
-          var modelType = property.PropertyType.GetGenericArguments()[0];
-
-          var route = new RouteDefinition
-          {
-            ModelType = modelType,
-            PathString = RouteBuilder.BuildRoute(Namespace, property.Name),
-            ContextPropertyName = property.Name
-          };
+      ContextType = typeof(T);
 
-          Routes.Add(route);
-        }
-      });
+      if (!typeof(DbContext).IsAssignableFrom(ContextType))
+        throw new ArgumentException("Context Type must derive from DbContext", nameof(T));
     }
-
   }
 }

JsonApiDotNetCore/Controllers/ControllerBuilder.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
 using JsonApiDotNetCore.Abstractions;
 using JsonApiDotNetCore.Data;
 
@@ -13,9 +16,36 @@ public ControllerBuilder(JsonApiContext context)
       _context = context;
     }
 
-    public JsonApiController BuildController()
+    public IJsonApiController BuildController()
     {
-      return new JsonApiController(_context, new ResourceRepository(_context));
+      var overrideController = GetOverrideController();
+      return overrideController ?? new JsonApiController(_context, new ResourceRepository(_context));
+    }
+
+    public IJsonApiController GetOverrideController()
+    {
+      Type controllerType;
+      return _context.Configuration.ControllerOverrides.TryGetValue(_context.GetEntityType(), out controllerType) ?
+        InstantiateController(controllerType) : null;
+    }
+
+    private IJsonApiController InstantiateController(Type controllerType)
+    {
+      var constructor = controllerType.GetConstructors()[0];
+      var parameters = constructor.GetParameters();
+      var services =
+        parameters.Select(param => GetService(param.ParameterType)).ToArray();
+      return (IJsonApiController) Activator.CreateInstance(controllerType, services);
+    }
+
+    private object GetService(Type serviceType)
+    {
+      if(serviceType == typeof(ResourceRepository))
+          return new ResourceRepository(_context);
+      if (serviceType == typeof(JsonApiContext))
+          return _context;
+
+      return _context.HttpContext.RequestServices.GetService(serviceType);
     }
   }
 }

JsonApiDotNetCore/Controllers/IJsonApiController.cs

@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+using System.Reflection;
+using Microsoft.AspNetCore.Mvc;
+
+namespace JsonApiDotNetCore.Controllers
+{
+  public interface IJsonApiController
+  {
+    ObjectResult Delete(string id);
+    ObjectResult Get();
+    ObjectResult Get(string id);
+    ObjectResult Patch(string id, Dictionary<PropertyInfo, object> entityPatch);
+    ObjectResult Post(object entity);
+  }
+}

JsonApiDotNetCore/Controllers/JsonApiController.cs

@@ -6,7 +6,7 @@
 
 namespace JsonApiDotNetCore.Controllers
 {
-  public class JsonApiController
+  public class JsonApiController : IJsonApiController
   {
     protected readonly JsonApiContext JsonApiContext;
     private readonly ResourceRepository _resourceRepository;
@@ -17,16 +17,16 @@ public JsonApiController(JsonApiContext jsonApiContext, ResourceRepository resou
       _resourceRepository = resourceRepository;
     }
 
-    public ObjectResult Get()
+    public virtual ObjectResult Get()
     {
       var entities = _resourceRepository.Get();
-      if(entities == null || entities.Count == 0) {
+      if(entities == null) {
         return new NotFoundObjectResult(null);
       }
       return new OkObjectResult(entities);
     }
 
-    public ObjectResult Get(string id)
+    public virtual ObjectResult Get(string id)
     {
       var entity = _resourceRepository.Get(id);
       if(entity == null) {
@@ -35,14 +35,14 @@ public ObjectResult Get(string id)
       return new OkObjectResult(entity);
     }
 
-    public ObjectResult Post(object entity)
+    public virtual ObjectResult Post(object entity)
     {
       _resourceRepository.Add(entity);
       _resourceRepository.SaveChanges();
       return new CreatedResult(JsonApiContext.HttpContext.Request.Path, entity);
     }
 
-    public ObjectResult Patch(string id, Dictionary<PropertyInfo, object> entityPatch)
+    public virtual ObjectResult Patch(string id, Dictionary<PropertyInfo, object> entityPatch)
     {
       var entity = _resourceRepository.Get(id);
       if(entity == null) {
@@ -55,7 +55,7 @@ public ObjectResult Patch(string id, Dictionary<PropertyInfo, object> entityPatc
       return new OkObjectResult(entity);
     }
 
-    public ObjectResult Delete(string id)
+    public virtual ObjectResult Delete(string id)
     {
       _resourceRepository.Delete(id);
       _resourceRepository.SaveChanges();

JsonApiDotNetCore/Extensions/IServiceCollectionExtensions.cs

@@ -10,14 +10,10 @@ public static class IServiceCollectionExtensions
   {
     public static void AddJsonApi(this IServiceCollection services, Action<IJsonApiModelConfiguration> configurationAction)
     {
-      var config = new JsonApiModelConfiguration();
-      configurationAction.Invoke(config);
-
-      if (config.ResourceMapper == null)
-      {
-        config.ResourceMapper = new MapperConfiguration(cfg => {}).CreateMapper();
-      }
-      services.AddSingleton(_ => new Router(config));
+      var configBuilder = new JsonApiConfigurationBuilder(configurationAction);
+      var config = configBuilder.Build();
+      IRouter router = new Router(config);
+      services.AddSingleton(_ => router);
     }
   }
 }

JsonApiDotNetCore/Routing/Router.cs

@@ -48,7 +48,7 @@ private void CallController()
       SendResponse(result);
     }
 
-    private ObjectResult ActivateControllerMethod(JsonApiController controller)
+    private ObjectResult ActivateControllerMethod(IJsonApiController controller)
     {
       var route = _jsonApiContext.Route;
       switch (route.RequestMethod)

JsonApiDotNetCoreExample/Controllers/TodoItemsController.cs

@@ -0,0 +1,24 @@
+using JsonApiDotNetCore.Controllers;
+using JsonApiDotNetCore.Abstractions;
+using JsonApiDotNetCore.Data;
+using JsonApiDotNetCoreExample.Data;
+using Microsoft.AspNetCore.Mvc;
+using System.Linq;
+
+namespace JsonApiDotNetCoreExample.Controllers
+{
+  public class TodoItemsController : JsonApiController, IJsonApiController
+  {
+    private readonly ApplicationDbContext _dbContext;
+
+    public TodoItemsController(JsonApiContext jsonApiContext, ResourceRepository resourceRepository, ApplicationDbContext applicationDbContext) : base(jsonApiContext, resourceRepository)
+    {
+      _dbContext = applicationDbContext;
+    }
+
+    public override ObjectResult Get()
+    {
+      return new OkObjectResult(_dbContext.TodoItems.ToList());
+    }
+  }
+}