log(output-formatter): add basic logging

Author: jaredcnance

README.md

@@ -1,32 +1,5 @@
 [![build status](https://gitlab.cmh.edu/jcnance/JsonApiDotnetCore/badges/master/build.svg)](https://gitlab.cmh.edu/jcnance/JsonApiDotnetCore/commits/master)
 
-# Task List 
-
-- [x] Add inbound serialization formatting
-- [x] Add POST
-- [x] Add PATCH
-- [x] Add DELETE
-- [x] Add Relationships
-- [x] Add support for authorization/context-scoping middleware
-- [x] Filtering
-- [x] Sorting
-- [x] Fetching relationships
-- [x] Creating relationships
-- [x] Refactor relationships links to use an POCO that contains data and links objects
-- [x] Include Entities
-- [x] BadRequest should be 422 in POST
-- [x] Dasherized route support
-- [x] Contributing Guide
-- [ ] Pagination
-- [ ] Add integration tests to example project
-- [ ] Add logging
-- [ ] Configure Different Repositories
-- [ ] Build definitions
-- [ ] Tests
-- [ ] Allow for presenters with mappings
-- [ ] Ability to disable dasherization of names
-- [ ] Rename ContextEntity ?? 
-
 # Generators
 
 - TODO: Document usage of the yeoman jadn generator

src/JsonApiDotNetCore/Data/DefaultEntityRepository.cs

@@ -128,7 +128,7 @@ public virtual IQueryable<TEntity> Include(IQueryable<TEntity> entities, string
             var entity = _jsonApiContext.RequestEntity;
             if(entity.Relationships.Any(r => r.RelationshipName == relationshipName))
                 return entities.Include(relationshipName);
-
+            
             throw new JsonApiException("400", "Invalid relationship",
                 $"{entity.EntityName} does not have a relationship named {relationshipName}");
         }

src/JsonApiDotNetCore/Formatters/JsonApiOutputFormatter.cs

@@ -1,12 +1,12 @@
 using System;
-using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Serialization;
 using JsonApiDotNetCore.Services;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
 
 namespace JsonApiDotNetCore.Formatters
@@ -28,22 +28,31 @@ public async Task WriteAsync(OutputFormatterWriteContext context)
             if (context == null)
                 throw new ArgumentNullException(nameof(context));
 
+            var logger = GetService<ILoggerFactory>(context)?
+                .CreateLogger<JsonApiOutputFormatter>();
+
+            logger?.LogInformation("Formatting response as JSONAPI");
+
             var response = context.HttpContext.Response;
 
             using (var writer = context.WriterFactory(response.Body, Encoding.UTF8))
             {
-                var jsonApiContext = context.HttpContext.RequestServices.GetService<IJsonApiContext>();
+                var jsonApiContext = GetService<IJsonApiContext>(context);
 
                 string responseContent;
                 try
                 {
                     if(context.Object.GetType() == typeof(Error))
+                    {
+                        logger?.LogInformation("Response was type <Error>. Serializing as plain JSON.");
                         responseContent = JsonConvert.SerializeObject(context.Object);
+                    }
                     else
                         responseContent = JsonApiSerializer.Serialize(context.Object, jsonApiContext);
                 }
                 catch(Exception e)
                 {
+                    logger?.LogError("An error ocurred while formatting the response.", e);
                     responseContent = new Error("400", e.Message).GetJson();
                     response.StatusCode = 400;
                 }
@@ -52,5 +61,10 @@ public async Task WriteAsync(OutputFormatterWriteContext context)
                 await writer.FlushAsync();       
             }
         }
+
+        private T GetService<T>(OutputFormatterWriteContext context)
+        {
+            return context.HttpContext.RequestServices.GetService<T>();
+        }
     }
 }

src/JsonApiDotNetCore/Middleware/JsonApiExceptionFilter.cs

@@ -17,7 +17,7 @@ public JsonApiExceptionFilter(ILoggerFactory loggerFactory)
 
         public void OnException(ExceptionContext context)
         {
-            _logger.LogError(new EventId(), context.Exception, "An unhandled exception occurred during the request");
+            _logger?.LogError(new EventId(), context.Exception, "An unhandled exception occurred during the request");
 
             var jsonApiException = context.Exception as JsonApiException;