(文字列ではなく) リストであるヘッダーに関連する dart rpc および shell (shelf_rpc を使用) を実行するときの非互換性。
(文字列ではなく) リストであるヘッダーに関連する dart rpc と shell (shelf_rpc を使用) を実行すると、非互換性があるようです。
スローされるエラーは (shelf[0.5.7]、shelf_rpc[0.0.3]、rpc[0.4.2]: の場合):
Error thrown by handler.
type 'List' is not a subtype of type 'String' of 'value'.
package:collection/src/canonicalized_map.dart 66:30 CanonicalizedMap.[]=
package:collection/src/canonicalized_map.dart 71:39 CanonicalizedMap.addAll.<fn>
dart:collection _CompactLinkedHashMap.forEach
package:collection/src/canonicalized_map.dart 71:18 CanonicalizedMap.addAll
package:collection/src/canonicalized_map.dart 57:11 CanonicalizedMap.CanonicalizedMap.from
package:shelf/src/response.dart 215:9 Response.Response
package:shelf_rpc/shelf_rpc.dart 18:24 createRpcHandler.<fn>.<fn>
この問題を回避するには、shelf_rpc.dart を変更してリストを文字列に置き換えます。
// Copyright (c) 2015, 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 "package:shelf/shelf.dart";
import "package:rpc/rpc.dart";
/// Creates a Shelf [Handler] that translates Shelf [Request]s to rpc's
/// [HttpApiRequest] executes the request on the given [ApiServer] and then
/// translates the returned rpc's [HttpApiResponse] to a Shelf [Response].
Handler createRpcHandler(ApiServer apiServer) {
return (Request request) {
try {
var apiRequest = new HttpApiRequest(request.method, request.requestedUri,
request.headers, request.read());
return apiServer.handleHttpApiRequest(apiRequest).then(
(apiResponse) {
// EXTRA: print and work-around
printHeaders(apiResponse.headers, true);
printHeaders(apiResponse.headers, false);
// EXTRA <end>
return new Response(apiResponse.status, body: apiResponse.body,
headers: apiResponse.headers);
});
} catch (e) {
// Should never happen since the apiServer.handleHttpRequest method
// always returns a response.
return new Response.internalServerError(body: e.toString());
}
};
}
// EXTRA WORKAROUND: print headers & replace Lists by Strings
printHeaders(Map headers, bool replaceListsBytStrings) {
print('--HEADERS start---');
headers.forEach(
(key, value) {
print('key: $key - value: $value - type: ${value.runtimeType}');
if ( (replaceListsBytStrings) && (value is List) ) {
String str = value.toString().substring(1, value.toString().length-1);
headers[key] = str;
}
});
print('--HEADERS end---');
}
出力：
--HEADERS start---
key: content-type - value: application/json; charset=utf-8 - type: String
key: cache-control - value: no-cache, no-store, must-revalidate - type: String
key: pragma - value: no-cache - type: String
key: expires - value: 0 - type: String
key: access-control-allow-credentials - value: true - type: String
key: access-control-allow-origin - value: * - type: String
key: allow - value: [GET] - type: List
key: access-control-allow-methods - value: [GET] - type: List
key: access-control-allow-headers - value: origin, x-requested-with, content-type, accept - type: String
key: Access-Control-Allow-Headers - value: null,Authorization, content-type - type: String
--HEADERS end---
--HEADERS start---
key: content-type - value: application/json; charset=utf-8 - type: String
key: cache-control - value: no-cache, no-store, must-revalidate - type: String
key: pragma - value: no-cache - type: String
key: expires - value: 0 - type: String
key: access-control-allow-credentials - value: true - type: String
key: access-control-allow-origin - value: * - type: String
key: allow - value: GET - type: String
key: access-control-allow-methods - value: GET - type: String
key: access-control-allow-headers - value: origin, x-requested-with, content-type, accept - type: String
key: Access-Control-Allow-Headers - value: null,Authorization, content-type - type: String
--HEADERS end---