initial commit with cache support & example

2022-02-07 00:11:15 +06:00
commit c7169b04c7
65 changed files with 7155 additions and 0 deletions
@@ -0,0 +1,64 @@
+import 'dart:async';
+import 'package:fl_query/fl_query.dart';
+
+import "package:gql_transform_link/gql_transform_link.dart";
+
+typedef _RequestTransformer = FutureOr<Request> Function(Request request);
+
+typedef OnException = FutureOr<String> Function(
+  HttpLinkServerException exception,
+);
+
+/// Simple header-based authentication link that adds [headerKey]: [getToken()] to every request.
+///
+/// If a lazy or exception-based authentication link is needed for your use case,
+/// implementing your own from the [gql reference auth link] or opening an issue.
+///
+/// [gql reference auth link]: https://github.com/gql-dart/gql/blob/1884596904a411363165bcf3c7cfa9dcc2a61c26/examples/gql_example_http_auth_link/lib/http_auth_link.dart
+class AuthLink extends _AsyncReqTransformLink {
+  AuthLink({
+    required this.getToken,
+    this.headerKey = 'Authorization',
+  }) : super(requestTransformer: transform(headerKey, getToken));
+
+  /// Authentication callback. Note – must include prefixes, e.g. `'Bearer $token'`
+  final FutureOr<String?> Function() getToken;
+
+  /// Header key to set to the result of [getToken]
+  final String headerKey;
+
+  static _RequestTransformer transform(
+    String headerKey,
+    FutureOr<String?> Function() getToken,
+  ) =>
+      (Request request) async {
+        final token = await getToken();
+        return request.updateContextEntry<HttpLinkHeaders>(
+          (headers) => HttpLinkHeaders(
+            headers: <String, String>{
+              ...headers?.headers ?? <String, String>{},
+              if (token != null) headerKey: token,
+            },
+          ),
+        );
+      };
+}
+
+/// Version of [TransformLink] that handles async transforms
+class _AsyncReqTransformLink extends Link {
+  final _RequestTransformer requestTransformer;
+
+  _AsyncReqTransformLink({
+    required this.requestTransformer,
+  });
+
+  @override
+  Stream<Response> request(
+    Request request, [
+    NextLink? forward,
+  ]) async* {
+    final req = await requestTransformer(request);
+
+    yield* forward!(req);
+  }
+}