platform/lib/src/http/server.dart
2016-12-21 15:27:07 -05:00

433 lines
14 KiB
Dart

library angel_framework.http.server;
import 'dart:async';
import 'dart:io';
import 'dart:math' show Random;
import 'dart:mirrors';
import 'package:angel_route/angel_route.dart';
import 'package:json_god/json_god.dart' as god;
import 'angel_base.dart';
import 'angel_http_exception.dart';
import 'controller.dart';
import 'fatal_error.dart';
import 'request_context.dart';
import 'response_context.dart';
import 'routable.dart';
import 'service.dart';
export 'package:container/container.dart';
final RegExp _straySlashes = new RegExp(r'(^/+)|(/+$)');
/// A function that binds an [Angel] server to an Internet address and port.
typedef Future<HttpServer> ServerGenerator(InternetAddress address, int port);
/// Handles an [AngelHttpException].
typedef Future AngelErrorHandler(
AngelHttpException err, RequestContext req, ResponseContext res);
/// A function that configures an [AngelBase] server in some way.
typedef Future AngelConfigurer(AngelBase app);
/// A powerful real-time/REST/MVC server class.
class Angel extends AngelBase {
StreamController<HttpRequest> _afterProcessed =
new StreamController<HttpRequest>.broadcast();
StreamController<HttpRequest> _beforeProcessed =
new StreamController<HttpRequest>.broadcast();
StreamController<AngelFatalError> _fatalErrorStream =
new StreamController<AngelFatalError>.broadcast();
StreamController<Controller> _onController =
new StreamController<Controller>.broadcast();
final List<Angel> _children = [];
Angel _parent;
final Random _rand = new Random.secure();
ServerGenerator _serverGenerator = HttpServer.bind;
/// Fired after a request is processed. Always runs.
Stream<HttpRequest> get afterProcessed => _afterProcessed.stream;
/// Fired before a request is processed. Always runs.
Stream<HttpRequest> get beforeProcessed => _beforeProcessed.stream;
/// All child application mounted on this instance.
List<Angel> get children => new List<Angel>.unmodifiable(_children);
/// Fired on fatal errors.
Stream<AngelFatalError> get fatalErrorStream => _fatalErrorStream.stream;
/// Indicates whether the application is running in a production environment.
///
/// The criteria for this is the `ANGEL_ENV` environment variable being set to
/// `'production'`.
bool get isProduction => Platform.environment['ANGEL_ENV'] == 'production';
/// Fired whenever a controller is added to this instance.
///
/// **NOTE**: This is a broadcast stream.
Stream<Controller> get onController => _onController.stream;
/// Returns the parent instance of this application, if any.
Angel get parent => _parent;
/// Always run before responses are sent.
///
/// These will only not run if an [AngelFatalError] occurs.
final List<RequestHandler> responseFinalizers = [];
/// Default error handler, show HTML error page
AngelErrorHandler _errorHandler =
(AngelHttpException e, req, ResponseContext res) {
res.headers[HttpHeaders.CONTENT_TYPE] = ContentType.HTML.toString();
res.statusCode = e.statusCode;
res.write("<!DOCTYPE html><html><head><title>${e.message}</title>");
res.write("</head><body><h1>${e.message}</h1><ul>");
for (String error in e.errors) {
res.write("<li>$error</li>");
}
res.write("</ul></body></html>");
res.end();
};
/// The handler currently configured to run on [AngelHttpException]s.
AngelErrorHandler get errorHandler => _errorHandler;
/// [RequestMiddleware] to be run before all requests.
final List before = [];
/// [RequestMiddleware] to be run after all requests.
final List after = [];
/// The native HttpServer running this instancce.
HttpServer httpServer;
/// Handles a server error.
_onError(e, [StackTrace st]) {
_fatalErrorStream.add(new AngelFatalError(error: e, stack: st));
}
void _printDebug(x) {
if (debug) print(x);
}
String _randomString(int length) {
var codeUnits = new List.generate(length, (index) {
return _rand.nextInt(33) + 89;
});
return new String.fromCharCodes(codeUnits);
}
/// Starts the server.
///
/// Returns false on failure; otherwise, returns the HttpServer.
Future<HttpServer> startServer([InternetAddress address, int port]) async {
final host = address ?? InternetAddress.LOOPBACK_IP_V4;
this.httpServer = await _serverGenerator(host, port ?? 0);
return httpServer..listen(handleRequest);
}
/// Loads some base dependencies into the service container.
void bootstrapContainer() {
container.singleton(this, as: AngelBase);
container.singleton(this, as: Routable);
container.singleton(this, as: Router);
container.singleton(this);
if (runtimeType != Angel) container.singleton(this, as: Angel);
}
Future<bool> executeHandler(
handler, RequestContext req, ResponseContext res) async {
if (handler is RequestMiddleware) {
var result = await handler(req, res);
if (result is bool)
return result == true;
else if (result != null) {
res.json(result);
return false;
} else
return res.isOpen;
}
if (handler is RequestHandler) {
await handler(req, res);
return res.isOpen;
}
if (handler is Future) {
var result = await handler;
if (result is bool)
return result == true;
else if (result != null) {
res.json(result);
return false;
} else
return true;
}
if (handler is Function) {
var result = await runContained(handler, req, res);
if (result is bool)
return result == true;
else if (result != null) {
res.json(result);
return false;
} else
return true;
}
if (requestMiddleware.containsKey(handler)) {
return await executeHandler(requestMiddleware[handler], req, res);
}
// res.willCloseItself = true;
res.write(god.serialize(handler));
// await res.io.close();
return false;
}
Future handleRequest(HttpRequest request) async {
_beforeProcessed.add(request);
final req = await RequestContext.from(request, this);
final res = new ResponseContext(request.response, this);
String requestedUrl = request.uri.path.replaceAll(_straySlashes, '');
if (requestedUrl.isEmpty) requestedUrl = '/';
final resolved =
resolveAll(requestedUrl, requestedUrl, method: request.method);
for (final result in resolved) req.params.addAll(result.allParams);
if (resolved.isNotEmpty) {
final route = resolved.first.route;
req.inject(Match, route.match(requestedUrl));
}
final m = new MiddlewarePipeline(resolved);
req.inject(MiddlewarePipeline, m);
final pipeline = []..addAll(before)..addAll(m.handlers)..addAll(after);
_printDebug('Handler sequence on $requestedUrl: $pipeline');
for (final handler in pipeline) {
try {
_printDebug('Executing handler: $handler');
final result = await executeHandler(handler, req, res);
_printDebug('Result: $result');
if (!result) {
_printDebug('Last executed handler: $handler');
break;
} else {
_printDebug(
'Handler completed successfully, did not terminate response: $handler');
}
} catch (e, st) {
_printDebug('Caught error in handler $handler: $e');
_printDebug(st);
if (e is AngelHttpException) {
// Special handling for AngelHttpExceptions :)
try {
res.statusCode = e.statusCode;
String accept = request.headers.value(HttpHeaders.ACCEPT);
if (accept == "*/*" ||
accept.contains(ContentType.JSON.mimeType) ||
accept.contains("application/javascript")) {
res.json(e.toMap());
} else {
await _errorHandler(e, req, res);
}
// _finalizeResponse(request, res);
} catch (e, st) {
_fatalErrorStream.add(
new AngelFatalError(request: request, error: e, stack: st));
}
} else {
_fatalErrorStream
.add(new AngelFatalError(request: request, error: e, stack: st));
}
break;
}
}
try {
_afterProcessed.add(request);
if (!res.willCloseItself) {
for (var finalizer in responseFinalizers) {
await finalizer(req, res);
}
for (var key in res.headers.keys) {
request.response.headers.set(key, res.headers[key]);
}
request.response.headers.chunkedTransferEncoding = res.chunked ?? true;
request.response
..statusCode = res.statusCode
..cookies.addAll(res.cookies)
..add(res.buffer.takeBytes());
await request.response.close();
}
} catch (e) {
failSilently(request, res);
}
}
// Run a function after injecting from service container
Future runContained(Function handler, RequestContext req, ResponseContext res,
{Map<String, dynamic> namedParameters}) async {
ClosureMirror closureMirror = reflect(handler);
List args = [];
for (ParameterMirror parameter in closureMirror.function.parameters) {
if (parameter.type.reflectedType == RequestContext)
args.add(req);
else if (parameter.type.reflectedType == ResponseContext)
args.add(res);
else {
// First, search to see if we can map this to a type
if (req.injections.containsKey(parameter.type.reflectedType)) {
args.add(req.injections[parameter.type.reflectedType]);
continue;
} else {
String name = MirrorSystem.getName(parameter.simpleName);
if (req.params.containsKey(name))
args.add(req.params[name]);
else if (name == "req")
args.add(req);
else if (name == "res")
args.add(res);
else if (req.injections.containsKey(name))
args.add(req.injections[name]);
else if (parameter.type.reflectedType != dynamic) {
args.add(container.make(parameter.type.reflectedType,
injecting: req.injections));
} else {
throw new Exception(
"Cannot resolve parameter '$name' within handler.");
}
}
}
}
return await closureMirror.apply(args).reflectee;
}
/// Applies an [AngelConfigurer] to this instance.
Future configure(AngelConfigurer configurer) async {
await configurer(this);
if (configurer is Controller)
_onController.add(controllers[configurer.exposeDecl.path] = configurer);
}
/// Fallback when an error is thrown while handling a request.
void failSilently(HttpRequest request, ResponseContext res) {}
/// Starts the server.
void listen({InternetAddress address, int port: 3000}) {
runZoned(() async {
await startServer(address, port);
}, onError: _onError);
}
/// Mounts the child on this router.
///
/// If the router is an [Angel] instance, all controllers
/// will be copied, as well as services and response finalizers.
///
/// [before] and [after] will be preserved.
///
/// NOTE: The above will not be properly copied if [path] is
/// a [RegExp].
@override
use(Pattern path, Routable routable,
{bool hooked: true, String namespace: null}) {
final head = path.toString().replaceAll(_straySlashes, '');
if (routable is Angel) {
_children.add(routable.._parent = this);
if (routable.before.isNotEmpty) {
all(path, (req, res) {
return true;
}, middleware: routable.before);
}
if (routable.after.isNotEmpty) {
all(path, (req, res) {
return true;
}, middleware: routable.after);
}
if (routable.responseFinalizers.isNotEmpty) {
responseFinalizers.add((req, res) async {
if (req.path.replaceAll(_straySlashes, '').startsWith(head)) {
for (var finalizer in routable.responseFinalizers)
await finalizer(req, res);
}
return true;
});
}
routable.controllers.forEach((k, v) {
final tail = k.toString().replaceAll(_straySlashes, '');
controllers['$head/$tail'.replaceAll(_straySlashes, '')] = v;
});
routable.services.forEach((k, v) {
final tail = k.toString().replaceAll(_straySlashes, '');
services['$head/$tail'.replaceAll(_straySlashes, '')] = v;
});
}
if (routable is Service) {
routable.app = this;
}
return super.use(path, routable, hooked: hooked, namespace: namespace);
}
/// Registers a callback to run upon errors.
onError(AngelErrorHandler handler) {
_errorHandler = handler;
}
Angel({bool debug: false}) : super(debug: debug) {
bootstrapContainer();
}
/// Creates an HTTPS server.
/// Provide paths to a certificate chain and server key (both .pem).
/// If no password is provided, a random one will be generated upon running
/// the server.
factory Angel.secure(String certificateChainPath, String serverKeyPath,
{bool debug: false, String password}) {
final app = new Angel(debug: debug);
app._serverGenerator = (InternetAddress address, int port) async {
var certificateChain =
Platform.script.resolve(certificateChainPath).toFilePath();
var serverKey = Platform.script.resolve(serverKeyPath).toFilePath();
var serverContext = new SecurityContext();
serverContext.useCertificateChain(certificateChain);
serverContext.usePrivateKey(serverKey,
password: password ?? app._randomString(8));
return await HttpServer.bindSecure(address, port, serverContext);
};
return app;
}
}