Hostnamerouter done

example/hostname.dart

@@ -0,0 +1,43 @@
+import 'dart:async';
+import 'package:angel_framework/angel_framework.dart';
+import 'package:angel_framework/http.dart';
+import 'package:logging/logging.dart';
+
+Future<void> apiConfigurer(Angel app) async {
+  app.get('/', (req, res) => 'Hello, API!');
+  app.fallback((req, res) {
+    return 'fallback on ${req.uri} (within the API)';
+  });
+}
+
+Future<void> frontendConfigurer(Angel app) async {
+  app.fallback((req, res) => '(usually an index page would be shown here.)');
+}
+
+main() async {
+  // Logging set up/boilerplate
+  Logger.root.onRecord.listen(print);
+
+  var app = Angel(logger: Logger('angel'));
+  var http = AngelHttp(app);
+  var multiHost = HostnameRouter.configure({
+    'api.localhost:3000': apiConfigurer,
+    'localhost:3000': frontendConfigurer,
+  });
+
+  app
+    ..fallback(multiHost.handleRequest)
+    ..fallback((req, res) {
+      res.write('Uncaught hostname: ${req.hostname}');
+    });
+
+  app.errorHandler = (e, req, res) {
+    print(e.message ?? e.error ?? e);
+    print(e.stackTrace);
+    return e.toJson();
+  };
+
+  await http.startServer('127.0.0.1', 3000);
+  print('Listening at ${http.uri}');
+  print('(See what happens when you visit http://localhost:3000 instead)');
+}

lib/src/core/core.dart

@@ -3,6 +3,8 @@ export 'controller.dart';
 export 'driver.dart';
 export 'env.dart';
 export 'hooked_service.dart';
+export 'hostname_parser.dart';
+export 'hostname_router.dart';
 export 'map_service.dart';
 export 'metadata.dart';
 export 'request_context.dart';

lib/src/core/hostname_parser.dart

@@ -4,9 +4,16 @@ import 'package:string_scanner/string_scanner.dart';
 /// Parses a string into a [RegExp] that is matched against hostnames.
 class HostnameSyntaxParser {
   final SpanScanner _scanner;
-  var _safe = RegExp(r"[0-9a-zA-Z-_]+");
+  var _safe = RegExp(r"[0-9a-zA-Z-_:]+");
 
-  HostnameSyntaxParser(String hostname) : _scanner = SpanScanner(hostname);
+  HostnameSyntaxParser(String hostname)
+      : _scanner = SpanScanner(hostname, sourceUrl: hostname);
+
+  FormatException _formatExc(String message) {
+    var span = _scanner.lastSpan ?? _scanner.emptySpan;
+    return FormatException(
+        '${span.start.toolString}: $message\n' + span.highlight(color: true));
+  }
 
   RegExp parse() {
     var b = StringBuffer();
@@ -15,13 +22,11 @@ class HostnameSyntaxParser {
     while (!_scanner.isDone) {
       if (_scanner.scan('|')) {
         if (parts.isEmpty) {
-          throw FormatException(
-              '${_scanner.emptySpan.end.toolString}: No hostname parts found before "|".');
+          throw _formatExc('No hostname parts found before "|".');
         } else {
           var next = _parseHostnamePart();
           if (next == null) {
-            throw FormatException(
-                '${_scanner.emptySpan.end.toolString}: No hostname parts found after "|".');
+            throw _formatExc('No hostname parts found after "|".');
           } else {
             var prev = parts.removeLast();
             parts.addLast('(($prev)|($next))');
@@ -30,6 +35,18 @@ class HostnameSyntaxParser {
       } else {
         var part = _parseHostnamePart();
         if (part != null) {
+          if (_scanner.scan('.')) {
+            var subPart = _parseHostnamePart(shouldThrow: false);
+            while (subPart != null) {
+              part += '\\.' + subPart;
+              if (_scanner.scan('.')) {
+                subPart = _parseHostnamePart(shouldThrow: false);
+              } else {
+                break;
+              }
+            }
+          }
+
           parts.add(part);
         }
       }
@@ -40,23 +57,24 @@ class HostnameSyntaxParser {
     }
 
     if (b.isEmpty) {
-      throw FormatException('Invalid or empty hostname.');
+      throw _formatExc('Invalid or empty hostname.');
     } else {
-      return RegExp(b.toString(), caseSensitive: false);
+      return RegExp('^$b\$', caseSensitive: false);
     }
   }
 
-  String _parseHostnamePart() {
+  String _parseHostnamePart({bool shouldThrow = true}) {
     if (_scanner.scan('*.')) {
-      return r'([^$]+\.)?';
+      return r'([^$.]+\.)?';
     } else if (_scanner.scan('*')) {
       return r'[^$]*';
+    } else if (_scanner.scan('+')) {
+      return r'[^$]+';
     } else if (_scanner.scan(_safe)) {
       return _scanner.lastMatch[0];
-    } else if (!_scanner.isDone) {
+    } else if (!_scanner.isDone && shouldThrow) {
       var s = String.fromCharCode(_scanner.peekChar());
-      throw FormatException(
-          '${_scanner.emptySpan.end.toolString}: Unexpected character "$s".');
+      throw _formatExc('Unexpected character "$s".');
     } else {
       return null;
     }

lib/src/core/hostname_router.dart

@@ -1,5 +1,122 @@
 import 'dart:async';
-import 'package:string_scanner/string_scanner.dart';
+import 'package:angel_container/angel_container.dart';
+import 'package:angel_route/angel_route.dart';
+import 'package:logging/logging.dart';
+import 'env.dart';
+import 'hostname_parser.dart';
 import 'request_context.dart';
 import 'response_context.dart';
+import 'routable.dart';
 import 'server.dart';
+
+/// A utility that allows requests to be handled based on their
+/// origin's hostname.
+///
+/// For example, an application could handle example.com and api.example.com
+/// separately.
+///
+/// The provided patterns can be any `Pattern`. If a `String` is provided, a simple
+/// grammar (see [HostnameSyntaxParser]) is used to create [RegExp].
+///
+/// For example:
+/// * `example.com` -> `/example\.com/`
+/// * `*.example.com` -> `/([^$.]\.)?example\.com/`
+/// * `example.*` -> `/example\./[^$]*`
+/// * `example.+` -> `/example\./[^$]+`
+class HostnameRouter {
+  final Map<Pattern, Angel> _apps = {};
+  final Map<Pattern, FutureOr<Angel> Function()> _creators = {};
+  final List<Pattern> _patterns = [];
+
+  HostnameRouter(
+      {Map<Pattern, Angel> apps = const {},
+      Map<Pattern, FutureOr<Angel> Function()> creators = const {}}) {
+    Map<Pattern, V> _parseMap<V>(Map<Pattern, V> map) {
+      return map.map((p, c) {
+        Pattern pp;
+
+        if (p is String) {
+          pp = HostnameSyntaxParser(p).parse();
+        } else {
+          pp = p;
+        }
+
+        return MapEntry(pp, c);
+      });
+    }
+
+    apps ??= {};
+    creators ??= {};
+    apps = _parseMap(apps);
+    creators = _parseMap(creators);
+    var patterns = apps.keys.followedBy(creators.keys).toSet().toList();
+    _apps.addAll(apps);
+    _creators.addAll(creators);
+    _patterns.addAll(patterns);
+    // print(_creators);
+  }
+
+  factory HostnameRouter.configure(
+      Map<Pattern, FutureOr<void> Function(Angel)> configurers,
+      {Reflector reflector = const EmptyReflector(),
+      AngelEnvironment environment = angelEnv,
+      Logger logger,
+      bool allowMethodOverrides = true,
+      FutureOr<String> Function(dynamic) serializer,
+      ViewGenerator viewGenerator}) {
+    var creators = configurers.map((p, c) {
+      return MapEntry(p, () async {
+        var app = Angel(
+            reflector: reflector,
+            environment: environment,
+            logger: logger,
+            allowMethodOverrides: allowMethodOverrides,
+            serializer: serializer,
+            viewGenerator: viewGenerator);
+        await app.configure(c);
+        return app;
+      });
+    });
+    return HostnameRouter(creators: creators);
+  }
+
+  /// Attempts to handle a request, according to its hostname.
+  ///
+  /// If none is matched, then `true` is returned.
+  /// Also returns `true` if all of the sub-app's handlers returned
+  /// `true`.
+  Future<bool> handleRequest(RequestContext req, ResponseContext res) async {
+    if (req.hostname != null) {
+      for (var pattern in _patterns) {
+        // print('${req.hostname} vs $_creators');
+        if (pattern.allMatches(req.hostname).isNotEmpty) {
+          // Resolve the entire pipeline within the context of the selected app.
+          var app = _apps[pattern] ??= (await _creators[pattern]());
+          // print('App for ${req.hostname} = $app from $pattern');
+          // app.dumpTree();
+
+          var r = app.optimizedRouter;
+          var resolved =
+              r.resolveAbsolute(req.path, method: req.method);
+          var pipeline = MiddlewarePipeline<RequestHandler>(resolved);
+          // print('Pipeline: $pipeline');
+          for (var handler in pipeline.handlers) {
+            // print(handler);
+            // Avoid stack overflow.
+            if (handler == handleRequest) {
+              continue;
+            } else if (!await app.executeHandler(handler, req, res)) {
+              // print('$handler TERMINATED');
+              return false;
+            } else {
+              // print('$handler CONTINUED');
+            }
+          }
+        }
+      }
+    }
+
+    // Otherwise, return true.
+    return true;
+  }
+}