Generic resource definitions

docs/usage/meta.md

@@ -1,43 +1,60 @@
 # Metadata
 
-Non-standard metadata can be added to your API responses in two ways: Resource and Request Meta. In the event of a key collision, the Request Meta will take precendence.
+Top-level custom metadata can be added to your API responses in two ways: globally and per resource type. In the event of a key collision, the resource meta will take precendence.
 
-## Resource Meta
+## Global Meta
 
-Resource Meta is metadata defined on the resource itself by implementing the `IHasMeta` interface.
+Global metadata can be added by injecting a service that implements `IResponseMeta`.
+This is useful if you need access to other injected services to build the meta object.
 
 ```c#
-public class Person : Identifiable, IHasMeta
+public class ResponseMetaService : IResponseMeta
 {
+    public ResponseMetaService(/*...other dependencies here */) {
+        // ...
+    }
+
     public Dictionary<string, object> GetMeta()
     {
         return new Dictionary<string, object>
         {
             {"copyright", "Copyright 2018 Example Corp."},
-            {"authors", new[] {"John Doe"}}
+            {"authors", new string[] {"John Doe"}}
         };
     }
 }
 ```
 
-## Request Meta
+```json
+{
+  "meta": {
+    "copyright": "Copyright 2018 Example Corp.",
+    "authors": [
+      "John Doe"
+    ]
+  },
+  "data": {
+    // ...
+  }
+}
+```
 
-Request Meta can be added by injecting a service that implements `IRequestMeta`.
-This is useful if you need access to other injected services to build the meta object.
+## Resource Meta
+
+Resource-specific metadata can be added by implementing `IResourceDefinition<TResource, TId>.GetMeta` (or overriding it on `JsonApiResourceDefinition`):
 
 ```c#
-public class RequestMetaService : IRequestMeta
+public class PersonDefinition : JsonApiResourceDefinition<Person>
 {
-    public RequestMetaService(/*...other dependencies here */) {
-        // ...
+    public PersonDefinition(IResourceGraph resourceGraph) : base(resourceGraph)
+    {
     }
 
-    public Dictionary<string, object> GetMeta()
+    public override IReadOnlyDictionary<string, object> GetMeta()
     {
         return new Dictionary<string, object>
         {
-            {"copyright", "Copyright 2018 Example Corp."},
-            {"authors", new string[] {"John Doe"}}
+            ["notice"] = "Check our intranet at http://www.example.com for personal details."
         };
     }
 }
@@ -46,10 +63,7 @@ public class RequestMetaService : IRequestMeta
 ```json
 {
   "meta": {
-    "copyright": "Copyright 2018 Example Corp.",
-    "authors": [
-      "John Doe"
-    ]
+    "notice": "Check our intranet at http://www.example.com for personal details."
   },
   "data": {
     // ...

src/JsonApiDotNetCore/Serialization/Building/MetaBuilder.cs

@@ -13,16 +13,16 @@ public class MetaBuilder<TResource> : IMetaBuilder<TResource> where TResource :
         private readonly IPaginationContext _paginationContext;
         private readonly IJsonApiOptions _options;
         private readonly IResourceDefinitionAccessor _resourceDefinitionAccessor;
-        private readonly IRequestMeta _requestMeta;
+        private readonly IResponseMeta _responseMeta;
 
         private Dictionary<string, object> _meta = new Dictionary<string, object>();
 
-        public MetaBuilder(IPaginationContext paginationContext, IJsonApiOptions options, IResourceDefinitionAccessor resourceDefinitionAccessor, IRequestMeta requestMeta = null)
+        public MetaBuilder(IPaginationContext paginationContext, IJsonApiOptions options, IResourceDefinitionAccessor resourceDefinitionAccessor, IResponseMeta responseMeta = null)
         {
             _paginationContext = paginationContext ?? throw new ArgumentNullException(nameof(paginationContext));
             _options = options ?? throw new ArgumentNullException(nameof(options));
             _resourceDefinitionAccessor = resourceDefinitionAccessor ?? throw new ArgumentNullException(nameof(resourceDefinitionAccessor));
-            _requestMeta = requestMeta;
+            _responseMeta = responseMeta;
         }
 
         /// <inheritdoc />
@@ -54,13 +54,11 @@ public IDictionary<string, object> GetMeta()
                 _meta.Add(key, _paginationContext.TotalResourceCount);
             }
 
-            if (_requestMeta != null)
+            if (_responseMeta != null)
             {
-                Add(_requestMeta.GetMeta());
+                Add(_responseMeta.GetMeta());
             }
 
-            // TODO: This looks wrong. We should be adding resource-level meta to each individual resource, instead of once at the top.
-
             var resourceMeta = _resourceDefinitionAccessor.GetMeta(typeof(TResource));
             if (resourceMeta != null)
             {

src/JsonApiDotNetCore/Serialization/IRequestMeta.cs → src/JsonApiDotNetCore/Serialization/IResponseMeta.cs

@@ -5,10 +5,10 @@
 namespace JsonApiDotNetCore.Serialization
 {
     /// <summary>
-    /// Service to add global top-level metadata to a <see cref="Document"/>.
+    /// Service to add global top-level json:api meta to a response <see cref="Document"/>.
     /// Use <see cref="IResourceDefinition{TResource,TId}.GetMeta"/> to specify top-level metadata per resource type.
     /// </summary>
-    public interface IRequestMeta
+    public interface IResponseMeta
     {
         IReadOnlyDictionary<string, object> GetMeta();
     }

test/JsonApiDotNetCoreExampleTests/Acceptance/Extensibility/RequestMetaTests.cs

@@ -21,12 +21,12 @@ public RequestMetaTests(IntegrationTestContext<Startup, AppDbContext> testContex
 
             testContext.ConfigureServicesBeforeStartup(services =>
             {
-                services.AddScoped<IRequestMeta, TestRequestMeta>();
+                services.AddScoped<IResponseMeta, TestResponseMeta>();
             });
         }
 
         [Fact]
-        public async Task Injecting_IRequestMeta_Adds_Meta_Data()
+        public async Task Injecting_IResponseMeta_Adds_Meta_Data()
         {
             // Arrange
             var route = "/api/v1/people";
@@ -43,7 +43,7 @@ public async Task Injecting_IRequestMeta_Adds_Meta_Data()
         }
     }
 
-    public sealed class TestRequestMeta : IRequestMeta
+    public sealed class TestResponseMeta : IResponseMeta
     {
         public IReadOnlyDictionary<string, object> GetMeta()
         {