Add custom encoders support for router

README.md

@@ -108,7 +108,11 @@ In your `configure.swift` file call the `register(graphQLSchema: Schema<YourReso
 
 ```Swift
 // Register the schema and it's resolver.
-app.register(graphQLSchema: todoSchema, withResolver: TodoAPI())
+app.register(
+  graphQLSchema: todoSchema,
+  withResolver: TodoAPI(),
+  customEncoder: GraphQLJSONEncoder()
+)
 ```
 
 ## License

Sources/GraphQLKit/Graphiti+Router.swift

@@ -3,18 +3,36 @@ import Graphiti
 import GraphQL
 
 extension RoutesBuilder {
-    public func register<RootType>(graphQLSchema schema: Schema<RootType, Request>, withResolver rootAPI: RootType, at path: PathComponent="graphql", postBodyStreamStrategy: HTTPBodyStreamStrategy = .collect) {
+    public func register<RootType>(
+        graphQLSchema schema: Schema<RootType, Request>,
+        withResolver rootAPI: RootType,
+        at path: PathComponent="graphql",
+        postBodyStreamStrategy: HTTPBodyStreamStrategy = .collect,
+        customEncoder: ContentEncoder? = nil
+    ) {
         self.on(.POST, path, body: postBodyStreamStrategy) { (request) -> EventLoopFuture<Response> in
-            try request.resolveByBody(graphQLSchema: schema, with: rootAPI)
-                .flatMap({
-                    $0.encodeResponse(status: .ok, for: request)
-                })
+            try request.resolveByBody(
+                graphQLSchema: schema,
+                with: rootAPI
+            ).flatMap { result in
+                result.encodeResponse(
+                    status: .ok,
+                    for: request,
+                    using: customEncoder
+                )
+            }
         }
         self.get(path) { (request) -> EventLoopFuture<Response> in
-            try request.resolveByQueryParameters(graphQLSchema: schema, with: rootAPI)
-                .flatMap({
-                    $0.encodeResponse(status: .ok, for: request)
-                })
+            try request.resolveByQueryParameters(
+                graphQLSchema: schema,
+                with: rootAPI
+            ).flatMap { result in
+                result.encodeResponse(
+                    status: .ok,
+                    for: request,
+                    using: customEncoder
+                )
+            }
         }
     }
 }
@@ -23,4 +41,49 @@ enum GraphQLResolveError: Swift.Error {
     case noQueryFound
 }
 
-extension GraphQLResult: Content { }
+extension GraphQLResult: Content {
+    func encodeResponse(
+        status: HTTPStatus,
+        headers: HTTPHeaders = [:],
+        for request: Request,
+        using encoder: ContentEncoder?
+    ) -> EventLoopFuture<Response> {
+        if let encoder = encoder {
+            let response = Response()
+            do {
+                var body = ByteBufferAllocator().buffer(capacity: 0)
+                try encoder.encode(self, to: &body, headers: &response.headers)
+                response.body = Response.Body(buffer: body)
+
+                for (name, value) in headers {
+                    response.headers.replaceOrAdd(
+                        name: name,
+                        value: value
+                    )
+                }
+
+                response.status = status
+            } catch {
+                return request.eventLoop.makeFailedFuture(error)
+            }
+            return request.eventLoop.makeSucceededFuture(response)
+        } else {
+            return self.encodeResponse(
+                status: status,
+                headers: headers,
+                for: request
+            )
+        }
+    }
+}
+
+extension GraphQLJSONEncoder: ContentEncoder {
+    public func encode<E>(
+        _ encodable: E,
+        to body: inout ByteBuffer,
+        headers: inout HTTPHeaders
+    ) throws where E: Encodable {
+        headers.contentType = .json
+        try body.writeBytes(self.encode(encodable))
+    }
+}