4e69153e3e
git-subtree-dir: packages/graphql git-subtree-mainline:ac29392d7fgit-subtree-split:33e2f86ba7
80 lines
2.8 KiB
Dart
80 lines
2.8 KiB
Dart
import 'dart:async';
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import 'dart:io';
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import 'package:angel_framework/angel_framework.dart';
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import 'package:angel_framework/http.dart';
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import 'package:graphql_schema/graphql_schema.dart';
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import 'package:graphql_server/graphql_server.dart';
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import 'package:graphql_server/subscriptions_transport_ws.dart' as stw;
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import 'package:web_socket_channel/io.dart';
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/// A [RequestHandler] that serves a spec-compliant GraphQL backend, over WebSockets.
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/// This endpoint only supports WebSockets, and can be used to deliver subscription events.
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///
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/// `graphQLWS` uses the Apollo WebSocket protocol, for the sake of compatibility with
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/// existing tooling.
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///
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/// See:
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/// * https://github.com/apollographql/subscriptions-transport-ws
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RequestHandler graphQLWS(GraphQL graphQL, {Duration keepAliveInterval}) {
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return (req, res) async {
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if (req is HttpRequestContext) {
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if (WebSocketTransformer.isUpgradeRequest(req.rawRequest)) {
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await res.detach();
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var socket = await WebSocketTransformer.upgrade(req.rawRequest,
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protocolSelector: (protocols) {
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if (protocols.contains('graphql-ws')) {
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return 'graphql-ws';
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} else {
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throw AngelHttpException.badRequest(
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message: 'Only the "graphql-ws" protocol is allowed.');
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}
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});
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var channel = IOWebSocketChannel(socket);
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var client = stw.RemoteClient(channel.cast<String>());
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var server =
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_GraphQLWSServer(client, graphQL, req, res, keepAliveInterval);
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await server.done;
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} else {
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throw AngelHttpException.badRequest(
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message: 'The `graphQLWS` endpoint only accepts WebSockets.');
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}
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} else {
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throw AngelHttpException.badRequest(
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message: 'The `graphQLWS` endpoint only accepts HTTP/1.1 requests.');
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}
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};
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}
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class _GraphQLWSServer extends stw.Server {
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final GraphQL graphQL;
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final RequestContext req;
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final ResponseContext res;
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_GraphQLWSServer(stw.RemoteClient client, this.graphQL, this.req, this.res,
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Duration keepAliveInterval)
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: super(client, keepAliveInterval: keepAliveInterval);
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@override
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bool onConnect(stw.RemoteClient client, [Map connectionParams]) => true;
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@override
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Future<stw.GraphQLResult> onOperation(String id, String query,
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[Map<String, dynamic> variables, String operationName]) async {
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try {
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var globalVariables = <String, dynamic>{
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'__requestctx': req,
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'__responsectx': res,
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};
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var data = await graphQL.parseAndExecute(
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query,
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operationName: operationName,
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sourceUrl: 'input',
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globalVariables: globalVariables,
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variableValues: variables,
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);
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return stw.GraphQLResult(data);
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} on GraphQLException catch (e) {
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return stw.GraphQLResult(null, errors: e.errors);
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}
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}
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}
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