Merge pull request #38 from Research-Institute/meta-objects

Meta objects

Author: jaredcnance

README.md

@@ -24,6 +24,7 @@ JsonApiDotnetCore provides a framework for building [json:api](http://jsonapi.or
 	- [Pagination](#pagination)
 	- [Filtering](#filtering)
 	- [Sorting](#sorting)
+    - [Meta](#meta)
 - [Tests](#tests)
 
 ## Installation
@@ -240,6 +241,18 @@ when setting up the services:
      opt => opt.DefaultPageSize = 10);
 ```
 
+**Total Record Count**
+
+The total number of records can be added to the document meta by setting it in the options:
+
+```
+services.AddJsonApi<AppDbContext>(opt =>
+{
+    opt.DefaultPageSize = 5;
+    opt.IncludeTotalRecordCount = true;
+});
+```
+
 ### Filtering
 
 You can filter resources by attributes using the `filter` query parameter. 
@@ -270,6 +283,25 @@ Resources can be sorted by an attribute:
 ?sort=-attribute // descending
 ```
 
+### Meta
+
+Resource meta can be defined by implementing `IHasMeta` on the model class:
+
+```
+public class Person : Identifiable<int>, IHasMeta
+{
+    // ...
+
+    public Dictionary<string, object> GetMeta(IJsonApiContext context)
+    {
+        return new Dictionary<string, object> {
+            { "copyright", "Copyright 2015 Example Corp." },
+            { "authors", new string[] { "Jared Nance" } }
+        };
+    }
+}
+```
+
 ## Tests
 
 I am using DotNetCoreDocs to generate sample requests and documentation.

src/JsonApiDotNetCore/Builders/DocumentBuilder.cs

@@ -1,5 +1,6 @@
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Models;
@@ -24,7 +25,8 @@ public Document Build(IIdentifiable entity)
 
             var document = new Document
             {
-                Data = _getData(contextEntity, entity)
+                Data = _getData(contextEntity, entity),
+                Meta = _getMeta(entity)
             };
 
             document.Included = _appendIncludedObject(document.Included, contextEntity, entity);
@@ -42,7 +44,8 @@ public Documents Build(IEnumerable<IIdentifiable> entities)
 
             var documents = new Documents
             {
-                Data = new List<DocumentData>()
+                Data = new List<DocumentData>(),
+                Meta = _getMeta(entities.FirstOrDefault())
             };
 
             foreach (var entity in entities)
@@ -54,6 +57,23 @@ public Documents Build(IEnumerable<IIdentifiable> entities)
             return documents;
         }
 
+        private Dictionary<string, object> _getMeta(IIdentifiable entity)
+        {
+            if (entity == null) return null;
+
+            var meta = new Dictionary<string, object>();
+            var metaEntity = entity as IHasMeta;
+            
+            if(metaEntity != null)
+                meta = metaEntity.GetMeta(_jsonApiContext);
+
+            if(_jsonApiContext.Options.IncludeTotalRecordCount)
+                meta["total-records"] = _jsonApiContext.TotalRecords;
+            
+            if(meta.Count > 0) return meta;
+            return null;
+        }
+
         private List<DocumentData> _appendIncludedObject(List<DocumentData> includedObject, ContextEntity contextEntity, IIdentifiable entity)
         {
             var includedEntities = _getIncludedEntities(contextEntity, entity);

src/JsonApiDotNetCore/Configuration/JsonApiOptions.cs

@@ -4,5 +4,6 @@ public class JsonApiOptions
     {
         public string Namespace { get; set; }
         public int DefaultPageSize { get; set; }
+        public bool IncludeTotalRecordCount { get; set; }
     }
 }

src/JsonApiDotNetCore/Controllers/JsonApiController.cs

@@ -64,6 +64,9 @@ public virtual async Task<IActionResult> GetAsync()
             if (_jsonApiContext.QuerySet != null && _jsonApiContext.QuerySet.IncludedRelationships != null && _jsonApiContext.QuerySet.IncludedRelationships.Count > 0)
                 entities = IncludeRelationships(entities, _jsonApiContext.QuerySet.IncludedRelationships);
 
+            if (_jsonApiContext.Options.IncludeTotalRecordCount)
+                _jsonApiContext.TotalRecords = await entities.CountAsync();
+
             // pagination should be done last since it will execute the query
             var pagedEntities = await ApplyPageQueryAsync(entities);
 

src/JsonApiDotNetCore/Models/Document.cs

@@ -1,14 +1,10 @@
-using System.Collections.Generic;
 using Newtonsoft.Json;
 
 namespace JsonApiDotNetCore.Models
 {
-    public class Document
+    public class Document : DocumentBase
     {
         [JsonProperty("data")]
         public DocumentData Data { get; set; }
-        
-        [JsonProperty("included")]
-        public List<DocumentData> Included { get; set; }
     }
 }

src/JsonApiDotNetCore/Models/DocumentBase.cs

@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace JsonApiDotNetCore.Models
+{
+    public class DocumentBase
+    {        
+        [JsonProperty("included")]
+        public List<DocumentData> Included { get; set; }
+        public Dictionary<string, object> Meta { get; set; }
+    }
+}

src/JsonApiDotNetCore/Models/Documents.cs

@@ -3,12 +3,9 @@
 
 namespace JsonApiDotNetCore.Models
 {
-    public class Documents
+    public class Documents : DocumentBase
     {
         [JsonProperty("data")]
         public List<DocumentData> Data { get; set; }
-
-        [JsonProperty("included")]
-        public List<DocumentData> Included { get; set; }
     }
 }

src/JsonApiDotNetCore/Models/IHasMeta.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using JsonApiDotNetCore.Services;
+
+namespace JsonApiDotNetCore.Models
+{
+    public interface IHasMeta
+    {
+        Dictionary<string, object> GetMeta(IJsonApiContext context);
+    }
+}

src/JsonApiDotNetCore/Services/IJsonApiContext.cs

@@ -15,5 +15,6 @@ public interface IJsonApiContext
         QuerySet QuerySet { get; set; }
         bool IsRelationshipData { get; set; }
         List<string> IncludedRelationships { get; set; }
+        int TotalRecords { get; set; }
     }
 }

src/JsonApiDotNetCore/Services/JsonApiContext.cs

@@ -20,13 +20,15 @@ public JsonApiContext(
             _httpContextAccessor = httpContextAccessor;
             Options = options;
         }
+
         public JsonApiOptions Options { get; set; }
         public IContextGraph ContextGraph { get; set; }
         public ContextEntity RequestEntity { get; set; }
         public string BasePath { get; set; }
         public QuerySet QuerySet { get; set; }
         public bool IsRelationshipData { get; set; }
         public List<string> IncludedRelationships { get; set; }
+        public int TotalRecords { get; set; }
 
         public IJsonApiContext ApplyContext<T>()
         {