feat(api): REST methods in dart with auth mode none (#1783)

packages/amplify/amplify_flutter/lib/src/hybrid_impl.dart

@@ -34,6 +34,7 @@ class AmplifyHybridImpl extends AmplifyClassImpl {
     );
     await Future.wait(
       [
+        ...API.plugins,
         ...Auth.plugins,
       ].map((p) => p.configure(config: amplifyConfig)),
       eagerError: true,

packages/api/amplify_api/lib/src/amplify_api_config.dart

@@ -0,0 +1,74 @@
+// Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License").
+// You may not use this file except in compliance with the License.
+// A copy of the License is located at
+//
+//  http://aws.amazon.com/apache2.0
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+import 'package:amplify_core/amplify_core.dart';
+import 'package:collection/collection.dart';
+import 'package:meta/meta.dart';
+
+const _slash = '/';
+
+@internal
+class EndpointConfig with AWSEquatable<EndpointConfig> {
+  const EndpointConfig(this.name, this.config);
+
+  final String name;
+  final AWSApiConfig config;
+
+  @override
+  List<Object?> get props => [name, config];
+
+  /// Gets the host with environment path prefix from Amplify config and combines
+  /// with [path] and [queryParameters] to return a full [Uri].
+  Uri getUri(String path, Map<String, dynamic>? queryParameters) {
+    final parsed = Uri.parse(config.endpoint);
+    // Remove leading slashes which are suggested in public documentation.
+    // https://docs.amplify.aws/lib/restapi/getting-started/q/platform/flutter/#make-a-post-request
+    if (path.startsWith(_slash)) {
+      path = path.substring(1);
+    }
+    // Avoid URI-encoding slashes in path from caller.
+    final pathSegmentsFromPath = path.split(_slash);
+    return parsed.replace(pathSegments: [
+      ...parsed.pathSegments,
+      ...pathSegmentsFromPath,
+    ], queryParameters: queryParameters);
+  }
+}
+
+@internal
+extension AWSApiPluginConfigHelpers on AWSApiPluginConfig {
+  EndpointConfig getEndpoint({
+    required EndpointType type,
+    String? apiName,
+  }) {
+    final typeConfigs =
+        entries.where((config) => config.value.endpointType == type);
+    if (apiName != null) {
+      final config = typeConfigs.firstWhere(
+        (config) => config.key == apiName,
+        orElse: () => throw ApiException(
+          'No API endpoint found matching apiName $apiName.',
+        ),
+      );
+      return EndpointConfig(config.key, config.value);
+    }
+    final onlyConfig = typeConfigs.singleOrNull;
+    if (onlyConfig == null) {
+      throw const ApiException(
+        'Multiple API endpoints defined. Pass apiName parameter to specify '
+        'which one to use.',
+      );
+    }
+    return EndpointConfig(onlyConfig.key, onlyConfig.value);
+  }
+}

packages/api/amplify_api/lib/src/amplify_authorization_rest_client.dart

@@ -0,0 +1,58 @@
+// Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'dart:async';
+
+import 'package:amplify_core/amplify_core.dart';
+import 'package:http/http.dart' as http;
+import 'package:meta/meta.dart';
+
+/// Implementation of http [http.Client] that authorizes HTTP requests with
+/// Amplify.
+@internal
+class AmplifyAuthorizationRestClient extends http.BaseClient
+    implements Closeable {
+  /// Determines how requests with this client are authorized.
+  final AWSApiConfig endpointConfig;
+  final http.Client _baseClient;
+  final bool _useDefaultBaseClient;
+
+  /// Provide an [AWSApiConfig] which will determine how requests from this
+  /// client are authorized.
+  AmplifyAuthorizationRestClient({
+    required this.endpointConfig,
+    http.Client? baseClient,
+  })  : _useDefaultBaseClient = baseClient == null,
+        _baseClient = baseClient ?? http.Client();
+
+  /// Implementation of [send] that authorizes any request without "Authorization"
+  /// header already set.
+  @override
+  Future<http.StreamedResponse> send(http.BaseRequest request) async =>
+      _baseClient.send(_authorizeRequest(request));
+
+  @override
+  void close() {
+    if (_useDefaultBaseClient) _baseClient.close();
+  }
+
+  http.BaseRequest _authorizeRequest(http.BaseRequest request) {
+    if (!request.headers.containsKey(AWSHeaders.authorization) &&
+        endpointConfig.authorizationType != APIAuthorizationType.none) {
+      // ignore: todo
+      // TODO: Use auth providers from core to transform the request.
+    }
+    return request;
+  }
+}

packages/api/amplify_api/lib/src/api_plugin_impl.dart

@@ -19,22 +19,36 @@ import 'dart:io';
 import 'package:amplify_api/amplify_api.dart';
 import 'package:amplify_api/src/native_api_plugin.dart';
 import 'package:amplify_core/amplify_core.dart';
+import 'package:async/async.dart';
 import 'package:flutter/services.dart';
+import 'package:http/http.dart' as http;
+import 'package:meta/meta.dart';
+
+import 'amplify_api_config.dart';
+import 'amplify_authorization_rest_client.dart';
+import 'util.dart';
 
 /// {@template amplify_api.amplify_api_dart}
 /// The AWS implementation of the Amplify API category.
 /// {@endtemplate}
 class AmplifyAPIDart extends AmplifyAPI {
   late final AWSApiPluginConfig _apiConfig;
+  final http.Client? _baseHttpClient;
+
+  /// A map of the keys from the Amplify API config to HTTP clients to use for
+  /// requests to that endpoint.
+  final Map<String, AmplifyAuthorizationRestClient> _clientPool = {};
 
   /// The registered [APIAuthProvider] instances.
   final Map<APIAuthorizationType, APIAuthProvider> _authProviders = {};
 
   /// {@macro amplify_api.amplify_api_dart}
   AmplifyAPIDart({
     List<APIAuthProvider> authProviders = const [],
+    http.Client? baseHttpClient,
     this.modelProvider,
-  }) : super.protected() {
+  })  : _baseHttpClient = baseHttpClient,
+        super.protected() {
     authProviders.forEach(registerAuthProvider);
   }
 
@@ -71,11 +85,158 @@ class AmplifyAPIDart extends AmplifyAPI {
     }
   }
 
+  /// Returns the HTTP client to be used for REST operations.
+  ///
+  /// Use [apiName] if there are multiple REST endpoints.
+  @visibleForTesting
+  http.Client getRestClient({String? apiName}) {
+    final endpoint = _apiConfig.getEndpoint(
+      type: EndpointType.rest,
+      apiName: apiName,
+    );
+    return _clientPool[endpoint.name] ??= AmplifyAuthorizationRestClient(
+      endpointConfig: endpoint.config,
+      baseClient: _baseHttpClient,
+    );
+  }
+
+  Uri _getRestUri(
+      String path, String? apiName, Map<String, dynamic>? queryParameters) {
+    final endpoint = _apiConfig.getEndpoint(
+      type: EndpointType.rest,
+      apiName: apiName,
+    );
+    return endpoint.getUri(path, queryParameters);
+  }
+
+  /// NOTE: http does not support request abort https://github.com/dart-lang/http/issues/424.
+  /// For now, just make a [CancelableOperation] to cancel the future.
+  /// To actually abort calls at network layer, need to call in
+  /// dart:io/dart:html or other library with custom http default Client() implementation.
+  CancelableOperation<T> _makeCancelable<T>(Future<T> responseFuture) {
+    return CancelableOperation.fromFuture(responseFuture);
+  }
+
+  CancelableOperation<AWSStreamedHttpResponse> _prepareRestResponse(
+      Future<AWSStreamedHttpResponse> responseFuture) {
+    return _makeCancelable(responseFuture);
+  }
+
   @override
   final ModelProviderInterface? modelProvider;
 
   @override
   void registerAuthProvider(APIAuthProvider authProvider) {
     _authProviders[authProvider.type] = authProvider;
   }
+
+  // ====== REST =======
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> delete(
+    String path, {
+    HttpPayload? body,
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(AWSStreamedHttpRequest.delete(
+      uri,
+      body: body ?? HttpPayload.empty(),
+      headers: addContentTypeToHeaders(headers, body),
+    ).send(client));
+  }
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> get(
+    String path, {
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(
+      AWSHttpRequest.get(
+        uri,
+        headers: headers,
+      ).send(client),
+    );
+  }
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> head(
+    String path, {
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(
+      AWSHttpRequest.head(
+        uri,
+        headers: headers,
+      ).send(client),
+    );
+  }
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> patch(
+    String path, {
+    HttpPayload? body,
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(
+      AWSStreamedHttpRequest.patch(
+        uri,
+        headers: addContentTypeToHeaders(headers, body),
+        body: body ?? HttpPayload.empty(),
+      ).send(client),
+    );
+  }
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> post(
+    String path, {
+    HttpPayload? body,
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(
+      AWSStreamedHttpRequest.post(
+        uri,
+        headers: addContentTypeToHeaders(headers, body),
+        body: body ?? HttpPayload.empty(),
+      ).send(client),
+    );
+  }
+
+  @override
+  CancelableOperation<AWSStreamedHttpResponse> put(
+    String path, {
+    HttpPayload? body,
+    Map<String, String>? headers,
+    Map<String, String>? queryParameters,
+    String? apiName,
+  }) {
+    final uri = _getRestUri(path, apiName, queryParameters);
+    final client = getRestClient(apiName: apiName);
+    return _prepareRestResponse(
+      AWSStreamedHttpRequest.put(
+        uri,
+        headers: addContentTypeToHeaders(headers, body),
+        body: body ?? HttpPayload.empty(),
+      ).send(client),
+    );
+  }
 }

packages/api/amplify_api/lib/src/method_channel_api.dart

@@ -26,6 +26,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 
 import '../amplify_api.dart';
+import 'util.dart';
 
 part 'auth_token.dart';
 
@@ -282,19 +283,12 @@ class AmplifyAPIMethodChannel extends AmplifyAPI {
   }) {
     // Send Request cancelToken to Native
     String cancelToken = uuid();
-    // Ensure Content-Type header matches payload.
-    var modifiedHeaders = headers != null ? Map.of(headers) : null;
-    final contentType = body?.contentType;
-    if (contentType != null) {
-      modifiedHeaders = modifiedHeaders ?? {};
-      modifiedHeaders.putIfAbsent(AWSHeaders.contentType, () => contentType);
-    }
     final responseFuture = _restResponseHelper(
       methodName: methodName,
       path: path,
       cancelToken: cancelToken,
       body: body,
-      headers: modifiedHeaders,
+      headers: addContentTypeToHeaders(headers, body),
       queryParameters: queryParameters,
       apiName: apiName,
     );