Finalize subscriptions

angel_graphql/example/subscription.dart

@@ -0,0 +1,99 @@
+// Inspired by:
+// https://www.apollographql.com/docs/apollo-server/features/subscriptions/#subscriptions-example
+
+import 'package:angel_file_service/angel_file_service.dart';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_framework/http.dart';
+import 'package:angel_graphql/angel_graphql.dart';
+import 'package:angel_serialize/angel_serialize.dart';
+import 'package:file/local.dart';
+import 'package:graphql_schema/graphql_schema.dart';
+import 'package:graphql_server/graphql_server.dart';
+import 'package:graphql_server/mirrors.dart';
+import 'package:http/io_client.dart';
+import 'package:logging/logging.dart';
+
+main() async {
+  var logger = Logger('angel_graphql');
+  var app = Angel(logger: logger);
+  var http = AngelHttp(app);
+  app.logger.onRecord.listen((rec) {
+    print(rec);
+    if (rec.error != null) print(rec.error);
+    if (rec.stackTrace != null) print(rec.stackTrace);
+  });
+
+  // Create an in-memory service.
+  var fs = LocalFileSystem();
+  var postService =
+      app.use('/api/posts', JsonFileService(fs.file('posts.json')));
+
+  // Also get a [Stream] of item creation events.
+  var postAdded = postService.afterCreated
+      .asStream()
+      .map((e) => {'postAdded': e.result})
+      .asBroadcastStream();
+
+  // GraphQL setup.
+  var postType = objectType('Post', fields: [
+    field('author', graphQLString),
+    field('comment', graphQLString),
+  ]);
+
+  var schema = graphQLSchema(
+    // Hooked up to the postService:
+    // type Query { posts: [Post] }
+    queryType: objectType(
+      'Query',
+      fields: [
+        field(
+          'posts',
+          listOf(postType),
+          resolve: resolveViaServiceIndex(postService),
+        ),
+      ],
+    ),
+
+    // Hooked up to the postService:
+    // type Mutation {
+    //  addPost(author: String!, comment: String!): Post
+    // }
+    mutationType: objectType(
+      'Mutation',
+      fields: [
+        field(
+          'addPost',
+          postType,
+          inputs: [
+            GraphQLFieldInput(
+                'data', postType.toInputObject('PostInput').nonNullable()),
+          ],
+          resolve: resolveViaServiceCreate(postService),
+        ),
+      ],
+    ),
+
+    // Hooked up to `postAdded`:
+    // type Subscription { postAdded: Post }
+    subscriptionType: objectType(
+      'Subscription',
+      fields: [
+        field('postAdded', postType, resolve: (_, __) => postAdded),
+      ],
+    ),
+  );
+
+  // Mount GraphQL routes; we'll support HTTP and WebSockets transports.
+  app.get('/graphql', graphQLHttp(GraphQL(schema)));
+  app.get('/graphql/subscriptions', graphQLWS(GraphQL(schema)));
+  app.get('/graphiql', graphiQL());
+
+  var server = await http.startServer('127.0.0.1', 3000);
+  var uri =
+      Uri(scheme: 'http', host: server.address.address, port: server.port);
+  var graphiqlUri = uri.replace(path: 'graphiql');
+  var postsUri = uri.replace(pathSegments: ['api', 'posts']);
+  print('Listening at $uri');
+  print('Access graphiql at $graphiqlUri');
+  print('Access posts service at $postsUri');
+}

angel_graphql/lib/angel_graphql.dart

@@ -1,3 +1,4 @@
 export 'src/graphiql.dart';
 export 'src/graphql_http.dart';
+export 'src/graphql_ws.dart';
 export 'src/resolvers.dart';

angel_graphql/lib/src/graphql_ws.dart

@@ -0,0 +1,36 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_framework/http.dart';
+import 'package:angel_validate/server.dart';
+import 'package:graphql_parser/graphql_parser.dart';
+import 'package:graphql_schema/graphql_schema.dart';
+import 'package:graphql_server/graphql_server.dart';
+
+/// A [RequestHandler] that serves a spec-compliant GraphQL backend, over WebSockets.
+/// This endpoint only supports WebSockets, and can be used to deliver subscription events.
+///
+/// `graphQLWS` uses the Apollo WebSocket protocol, for the sake of compatibility with
+/// existing tooling.
+///
+/// See:
+/// * https://github.com/apollographql/subscriptions-transport-ws
+RequestHandler graphQLWS(GraphQL graphQL) {
+  return (req, res) async {
+    if (req is HttpRequestContext) {
+      if (WebSocketTransformer.isUpgradeRequest(req.rawRequest)) {
+        await res.detach();
+        var socket = await WebSocketTransformer.upgrade(req.rawRequest);
+        // TODO: Apollo protocol
+        throw UnimplementedError('Apollo protocol not yet implemented.');
+      } else {
+        throw AngelHttpException.badRequest(
+            message: 'The `graphQLWS` endpoint only accepts WebSockets.');
+      }
+    } else {
+      throw AngelHttpException.badRequest(
+          message: 'The `graphQLWS` endpoint only accepts HTTP/1.1 requests.');
+    }
+  };
+}

angel_graphql/lib/src/resolvers.dart

@@ -62,6 +62,24 @@ GraphQLFieldResolver<Value, Serialized>
   };
 }
 
+/// A GraphQL resolver that `creates` a single value in an Angel service.
+///
+/// This resolver should be used on a field with at least the following input:
+/// * `data`: a [GraphQLObjectType] corresponding to the format of `data` to be passed to `create`
+///
+/// The arguments passed to the resolver will be forwarded to the service, and the
+/// service will receive [Providers.graphql].
+GraphQLFieldResolver<Value, Serialized>
+    resolveViaServiceCreate<Value, Serialized>(
+        Service<dynamic, Value> service) {
+  return (_, arguments) async {
+    var _requestInfo = _fetchRequestInfo(arguments);
+    var params = {'query': _getQuery(arguments), 'provider': Providers.graphQL}
+      ..addAll(_requestInfo);
+    return await service.create(arguments['data'] as Value, params);
+  };
+}
+
 /// A GraphQL resolver that `modifies` a single value from an Angel service.
 ///
 /// This resolver should be used on a field with at least the following inputs:
@@ -77,7 +95,6 @@ GraphQLFieldResolver<Value, Serialized>
     var _requestInfo = _fetchRequestInfo(arguments);
     var params = {'query': _getQuery(arguments), 'provider': Providers.graphQL}
       ..addAll(_requestInfo);
-    print(params);
     var id = arguments.remove(idField);
     return await service.modify(id, arguments['data'] as Value, params);
   };

angel_graphql/posts.json

@@ -0,0 +1 @@
+[]

angel_graphql/pubspec.yaml

@@ -6,6 +6,7 @@ author: Tobe O <thosakwe@gmail.com>
 environment:
   sdk: ">=2.0.0-dev <3.0.0"
 dependencies:
+  angel_file_service: ^2.0.0
   angel_framework: ^2.0.0-alpha
   angel_websocket: ^2.0.0
   angel_validate: ^2.0.0-alpha
@@ -16,6 +17,6 @@ dependencies:
 dev_dependencies:
   angel_serialize: ^2.0.0
   logging: ^0.11.0
-# dependency_overrides:
-#   graphql_server:
-#     path: ../graphql_server
+dependency_overrides:
+  graphql_server:
+    path: ../graphql_server

graphql_server/CHANGELOG.md

@@ -1,3 +1,6 @@
+# 1.0.0-beta.3
+* Introspection on subscription types (if any).
+
 # 1.0.0-beta.2
 * Fix bug where field aliases would not be resolved.
 

graphql_server/lib/graphql_server.dart

@@ -47,6 +47,8 @@ class GraphQL {
     if (_schema.queryType != null) this.customTypes.add(_schema.queryType);
     if (_schema.mutationType != null)
       this.customTypes.add(_schema.mutationType);
+    if (_schema.subscriptionType != null)
+      this.customTypes.add(_schema.subscriptionType);
   }
 
   GraphQLType convertType(TypeContext ctx) {
@@ -269,7 +271,7 @@ class GraphQL {
   ) async* {
     await for (var event in sourceStream) {
       yield await executeSubscriptionEvent(document, subscription, schema,
-          initialValue, variableValues, globalVariables, event);
+          event, variableValues, globalVariables);
     }
   }
 
@@ -279,8 +281,7 @@ class GraphQL {
       GraphQLSchema schema,
       initialValue,
       Map<String, dynamic> variableValues,
-      Map<String, dynamic> globalVariables,
-      event) async {
+      Map<String, dynamic> globalVariables) async {
     var selectionSet = subscription.selectionSet;
     var subscriptionType = schema.subscriptionType;
     if (subscriptionType == null)
@@ -290,7 +291,7 @@ class GraphQL {
     try {
       var data = await executeSelectionSet(document, selectionSet,
           subscriptionType, initialValue, variableValues, globalVariables);
-      return {'data': data, 'errors': []};
+      return {'data': data};
     } on GraphQLException catch (e) {
       return {
         'data': null,
@@ -384,7 +385,9 @@ class GraphQL {
     var argumentValues = field.field.arguments;
     var fieldName =
         field.field.fieldName.alias?.name ?? field.field.fieldName.name;
-    var desiredField = objectType.fields.firstWhere((f) => f.name == fieldName);
+    var desiredField = objectType.fields.firstWhere((f) => f.name == fieldName,
+        orElse: () => throw FormatException(
+            '${objectType.name} has no field named "$fieldName".'));
     var argumentDefinitions = desiredField.inputs;
 
     for (var argumentDefinition in argumentDefinitions) {
@@ -480,15 +483,13 @@ class GraphQL {
       String fieldName, Map<String, dynamic> argumentValues) async {
     var field = objectType.fields.firstWhere((f) => f.name == fieldName);
 
-    if (field.resolve == null) {
+    if (objectValue is Map) {
+      return objectValue[fieldName] as T;
+    } else if (field.resolve == null) {
       if (defaultFieldResolver != null)
         return await defaultFieldResolver(
             objectValue, fieldName, argumentValues);
 
-      if (objectValue is Map) {
-        return objectValue[fieldName] as T;
-      }
-
       return null;
     } else {
       return await field.resolve(objectValue, argumentValues) as T;
@@ -505,7 +506,7 @@ class GraphQL {
       Map<String, dynamic> globalVariables) async {
     if (fieldType is GraphQLNonNullableType) {
       var innerType = fieldType.ofType;
-      var completedResult = completeValue(document, fieldName, innerType,
+      var completedResult = await completeValue(document, fieldName, innerType,
           fields, result, variableValues, globalVariables);
 
       if (completedResult == null) {

graphql_server/lib/introspection.dart

@@ -89,6 +89,7 @@ GraphQLSchema reflectSchema(GraphQLSchema schema, List<GraphQLType> allTypes) {
   return new GraphQLSchema(
     queryType: objectType(schema.queryType.name, fields: fields),
     mutationType: schema.mutationType,
+    subscriptionType: schema.subscriptionType,
   );
 }
 
@@ -436,6 +437,10 @@ List<GraphQLType> fetchAllTypes(
     types.addAll(_fetchAllTypesFromObject(schema.mutationType));
   }
 
+  if (schema.subscriptionType != null) {
+    types.addAll(_fetchAllTypesFromObject(schema.subscriptionType));
+  }
+
   return types;
 }