| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'dart:async'; |
| |
| import 'package:collection/collection.dart'; |
| |
| import 'shelf_unmodifiable_map.dart'; |
| |
| /// Run [callback] and capture any errors that would otherwise be top-leveled. |
| /// |
| /// If [this] is called in a non-root error zone, it will just run [callback] |
| /// and return the result. Otherwise, it will capture any errors using |
| /// [runZoned] and pass them to [onError]. |
| void catchTopLevelErrors(void Function() callback, |
| void Function(dynamic error, StackTrace) onError) { |
| if (Zone.current.inSameErrorZone(Zone.root)) { |
| return runZoned(callback, onError: onError); |
| } else { |
| return callback(); |
| } |
| } |
| |
| /// Returns a [Map] with the values from [original] and the values from |
| /// [updates]. |
| /// |
| /// For keys that are the same between [original] and [updates], the value in |
| /// [updates] is used. |
| /// |
| /// If [updates] is `null` or empty, [original] is returned unchanged. |
| Map<K, V> updateMap<K, V>(Map<K, V> original, Map<K, V> updates) { |
| if (updates == null || updates.isEmpty) return original; |
| |
| return Map.from(original)..addAll(updates); |
| } |
| |
| /// Adds a header with [name] and [value] to [headers], which may be null. |
| /// |
| /// Returns a new map without modifying [headers]. |
| Map<String, dynamic> addHeader( |
| Map<String, dynamic> headers, String name, String value) { |
| headers = headers == null ? {} : Map.from(headers); |
| headers[name] = value; |
| return headers; |
| } |
| |
| /// Returns the header with the given [name] in [headers]. |
| /// |
| /// This works even if [headers] is `null`, or if it's not yet a |
| /// case-insensitive map. |
| String findHeader(Map<String, List<String>> headers, String name) { |
| if (headers == null) return null; |
| if (headers is ShelfUnmodifiableMap) { |
| return joinHeaderValues(headers[name]); |
| } |
| |
| for (var key in headers.keys) { |
| if (equalsIgnoreAsciiCase(key, name)) { |
| return joinHeaderValues(headers[key]); |
| } |
| } |
| return null; |
| } |
| |
| Map<String, List<String>> expandToHeadersAll( |
| Map<String, /* String | List<String> */ dynamic> headers) { |
| if (headers is Map<String, List<String>>) return headers; |
| if (headers == null || headers.isEmpty) return null; |
| |
| return Map<String, List<String>>.fromEntries(headers.entries.map((e) { |
| return MapEntry<String, List<String>>(e.key, expandHeaderValue(e.value)); |
| })); |
| } |
| |
| List<String> expandHeaderValue(dynamic v) { |
| if (v is String) { |
| return [v]; |
| } else if (v is List<String>) { |
| return v; |
| } else if (v == null) { |
| return null; |
| } else { |
| throw ArgumentError('Expected String or List<String>, got: `$v`.'); |
| } |
| } |
| |
| /// Multiple header values are joined with commas. |
| /// See http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-21#page-22 |
| String joinHeaderValues(List<String> values) { |
| if (values == null || values.isEmpty) return null; |
| if (values.length == 1) return values.single; |
| return values.join(','); |
| } |