Merge pull request #435 from mainawycliffe/handle-errors

Move Mutation Callbacks to MutationOptions

packages/graphql/lib/src/cache/in_memory_html.dart

@@ -73,7 +73,7 @@ class InMemoryCache implements Cache {
 
   Future<HashMap<String, dynamic>> _readFromStorage() async {
     try {
-      final decoded =  jsonDecode(window.localStorage[masterKey]);
+      final decoded = jsonDecode(window.localStorage[masterKey]);
       return HashMap.from(decoded);
     } catch (error) {
       // TODO: handle error

packages/graphql/lib/src/cache/in_memory_io.dart

@@ -12,13 +12,11 @@ import 'package:graphql/src/cache/cache.dart';
 import 'package:graphql/src/utilities/helpers.dart' show deeplyMergeLeft;
 import 'package:path/path.dart';
 
-
 class InMemoryCache implements Cache {
-
   InMemoryCache({
     this.storagePrefix = '',
   });
-  
+
   final FutureOr<String> storagePrefix;
 
   bool _writingToStorage = false;

packages/graphql/lib/src/cache/in_memory_stub.dart

@@ -4,6 +4,7 @@ import 'dart:collection';
 
 import 'package:graphql/src/cache/cache.dart';
 import 'package:meta/meta.dart';
+
 class InMemoryCache implements Cache {
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 
@@ -16,10 +17,10 @@ class InMemoryCache implements Cache {
   ///
   /// For vm/flutter, `storagePrefix` is a path to the directory
   /// that can save `cache.txt` file
-  /// 
-  /// For flutter usually provided by 
+  ///
+  /// For flutter usually provided by
   /// [path_provider.getApplicationDocumentsDirectory]
-  /// 
+  ///
   /// @NotNull
   final FutureOr<String> storagePrefix;
 

packages/graphql/lib/src/cache/normalized_in_memory.dart

@@ -76,7 +76,7 @@ class NormalizedInMemoryCache extends InMemoryCache {
   }
 
   @override
-  void reset(){
+  void reset() {
     data.clear();
   }
 

packages/graphql/lib/src/core/query_manager.dart

@@ -51,7 +51,24 @@ class QueryManager {
   }
 
   Future<QueryResult> mutate(MutationOptions options) {
-    return fetchQuery('0', options);
+    return fetchQuery('0', options).then((result) async {
+      // not sure why query id is '0', may be needs improvements
+      // once the mutation has been process successfully, execute callbacks
+      // before returning the results
+      final mutationCallbacks = MutationCallbacks(
+        cache: cache,
+        options: options,
+        queryId: '0',
+      );
+
+      final callbacks = mutationCallbacks.callbacks;
+
+      for (final callback in callbacks) {
+        await callback(result);
+      }
+
+      return result;
+    });
   }
 
   Future<QueryResult> fetchQuery(

packages/graphql/lib/src/core/query_options.dart

@@ -1,7 +1,10 @@
+import 'package:meta/meta.dart';
+
 import 'package:gql/ast.dart';
 import 'package:gql/language.dart';
-import 'package:meta/meta.dart';
 
+import 'package:graphql/client.dart';
+import 'package:graphql/internal.dart';
 import 'package:graphql/src/utilities/helpers.dart';
 import 'package:graphql/src/core/raw_operation_data.dart';
 
@@ -123,6 +126,10 @@ class QueryOptions extends BaseOptions {
   int pollInterval;
 }
 
+typedef OnMutationCompleted = void Function(dynamic data);
+typedef OnMutationUpdate = void Function(Cache cache, QueryResult result);
+typedef OnError = void Function(OperationException error);
+
 /// Mutation options
 class MutationOptions extends BaseOptions {
   MutationOptions({
@@ -133,13 +140,107 @@ class MutationOptions extends BaseOptions {
     FetchPolicy fetchPolicy,
     ErrorPolicy errorPolicy,
     Map<String, dynamic> context,
+    this.onCompleted,
+    this.update,
+    this.onError,
   }) : super(
           policies: Policies(fetch: fetchPolicy, error: errorPolicy),
           document: document,
           documentNode: documentNode,
           variables: variables,
           context: context,
         );
+
+  OnMutationCompleted onCompleted;
+  OnMutationUpdate update;
+  OnError onError;
+}
+
+class MutationCallbacks {
+  final MutationOptions options;
+  final Cache cache;
+  final String queryId;
+
+  MutationCallbacks({
+    this.options,
+    this.cache,
+    this.queryId,
+  })  : assert(cache != null),
+        assert(options != null),
+        assert(queryId != null);
+
+  // callbacks will be called against each result in the stream,
+  // which should then rebroadcast queries with the appropriate optimism
+  Iterable<OnData> get callbacks =>
+      <OnData>[onCompleted, update, onError].where(notNull);
+
+  // Todo: probably move this to its own class
+  OnData get onCompleted {
+    if (options.onCompleted != null) {
+      return (QueryResult result) {
+        if (!result.loading && !result.optimistic) {
+          return options.onCompleted(result.data);
+        }
+      };
+    }
+    return null;
+  }
+
+  OnData get onError {
+    if (options.onError != null) {
+      return (QueryResult result) {
+        if (!result.loading &&
+            result.hasException &&
+            options.errorPolicy != ErrorPolicy.ignore) {
+          return options.onError(result.exception);
+        }
+      };
+    }
+
+    return null;
+  }
+
+  /// The optimistic cache layer id `update` will write to
+  /// is a "child patch" of the default optimistic patch
+  /// created by the query manager
+  String get _patchId => '${queryId}.update';
+
+  /// apply the user's patch
+  void _optimisticUpdate(QueryResult result) {
+    final String patchId = _patchId;
+    // this is also done in query_manager, but better safe than sorry
+    assert(cache is OptimisticCache,
+        "can't optimisticly update non-optimistic cache");
+    (cache as OptimisticCache).addOptimisiticPatch(patchId, (Cache cache) {
+      options.update(cache, result);
+      return cache;
+    });
+  }
+
+  // optimistic patches will be cleaned up by the query_manager
+  // cleanup is handled by heirarchical optimism -
+  // as in, because our patch id is prefixed with '${observableQuery.queryId}.',
+  // it will be discarded along with the observableQuery.queryId patch
+  // TODO this results in an implicit coupling with the patch id system
+  OnData get update {
+    if (options.update != null) {
+      // dereference all variables that might be needed if the widget is disposed
+      final OnMutationUpdate widgetUpdate = options.update;
+      final OnData optimisticUpdate = _optimisticUpdate;
+
+      // wrap update logic to handle optimism
+      void updateOnData(QueryResult result) {
+        if (result.optimistic) {
+          return optimisticUpdate(result);
+        } else {
+          return widgetUpdate(cache, result);
+        }
+      }
+
+      return updateOnData;
+    }
+    return null;
+  }
 }
 
 // ObservableQuery options
@@ -218,10 +319,13 @@ class FetchMoreOptions {
     DocumentNode documentNode,
     this.variables = const <String, dynamic>{},
     @required this.updateQuery,
-  })  : assert((document != null && documentNode == null) ||
-            (document == null && documentNode != null)),
+  })  : assert(
+          _mutuallyExclusive(document, documentNode),
+          '"document" or "documentNode" options are mutually exclusive.',
+        ),
         assert(updateQuery != null),
-        documentNode = parseString(document);
+        this.documentNode =
+            documentNode ?? document != null ? parseString(document) : null;
 
   DocumentNode documentNode;
 
@@ -242,3 +346,12 @@ class FetchMoreOptions {
   /// with the result data already in the cache
   UpdateQuery updateQuery;
 }
+
+bool _mutuallyExclusive(
+  Object a,
+  Object b, {
+  bool required = false,
+}) =>
+    (!required && a == null && b == null) ||
+    (a != null && b == null) ||
+    (a == null && b != null);

packages/graphql/lib/src/core/raw_operation_data.dart

@@ -17,9 +17,14 @@ class RawOperationData {
     Map<String, dynamic> variables,
     String operationName,
   })  : assert(
+          document != null || documentNode != null,
+          'Either a "document"  or "documentNode" option is required. '
+          'You must specify your GraphQL document in the query options.',
+        ),
+        assert(
           (document != null && documentNode == null) ||
               (document == null && documentNode != null),
-          '"document" or "documentNode" option is required. You must specify your GraphQL document in the query options.',
+          '"document" or "documentNode" options are mutually exclusive.',
         ),
         documentNode = documentNode ?? parseString(document),
         _operationName = operationName,

packages/graphql/lib/src/link/http/link_http_helper_deprecated_io.dart

@@ -19,7 +19,7 @@ Future<Map<String, MultipartFile>> deprecatedHelper(
 
 bool isIoFile(object) {
   final r = object is io.File;
-  if(r) {
+  if (r) {
     print(r'''
 ⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️ DEPRECATION WARNING ⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️⚠️️️️️️️️
 

packages/graphql/lib/src/link/http/link_http_helper_deprecated_stub.dart

@@ -4,7 +4,9 @@ import 'package:http/http.dart';
 // in case the body is io.File
 // in future release, io.File will no longer be supported
 // but this stub is noop
-Future<Map<String, MultipartFile>> deprecatedHelper(body, currentMap, currentPath) async => null;
+Future<Map<String, MultipartFile>> deprecatedHelper(
+        body, currentMap, currentPath) async =>
+    null;
 
 // @deprecated, backward compatible only
 // in case the body is io.File

packages/graphql/lib/src/utilities/file_html.dart

@@ -4,20 +4,20 @@ import 'package:http/http.dart';
 import 'package:http_parser/http_parser.dart';
 
 Stream<List<int>> _readFile(html.File file) {
-    final reader = html.FileReader();
-    final streamController = StreamController<List<int>>();
+  final reader = html.FileReader();
+  final streamController = StreamController<List<int>>();
 
-    reader.onLoad.listen((_) {
-      // streamController.add(reader.result);
-      streamController.close();
-    });
+  reader.onLoad.listen((_) {
+    // streamController.add(reader.result);
+    streamController.close();
+  });
 
-    reader.onError.listen((error) => streamController.addError(error));
+  reader.onError.listen((error) => streamController.addError(error));
 
-    reader.readAsArrayBuffer(file);
+  reader.readAsArrayBuffer(file);
 
-    return streamController.stream;
-  }
+  return streamController.stream;
+}
 
 MultipartFile multipartFileFrom(html.File f) => MultipartFile(
       '',

packages/graphql/lib/src/utilities/file_stub.dart

@@ -2,4 +2,5 @@ import 'dart:async';
 
 import 'package:http/http.dart';
 
-FutureOr<MultipartFile> multipartFileFrom(/*io.File or html.File*/ f) => throw UnsupportedError('io or html');
+FutureOr<MultipartFile> multipartFileFrom(/*io.File or html.File*/ f) =>
+    throw UnsupportedError('io or html');

packages/graphql/test/link/http/link_http_test.dart

@@ -109,7 +109,7 @@ void main() {
       );
       expect(
         captured.body,
-        '{"operationName":"Operation","variables":{},"query":"query Operation {}"}',
+        '{"operationName":"Operation","variables":{},"query":"query Operation {\\n  \\n}"}',
       );
     });
 
@@ -163,7 +163,7 @@ void main() {
       );
       expect(
         captured.body,
-        '{"operationName":"Operation","variables":{},"extensions":null,"query":"query Operation {}"}',
+        '{"operationName":"Operation","variables":{},"extensions":null,"query":"query Operation {\\n  \\n}"}',
       );
     });
 
@@ -215,7 +215,7 @@ void main() {
       );
       expect(
         captured.body,
-        '{"operationName":"Operation","variables":{},"extensions":null,"query":"query Operation {}"}',
+        '{"operationName":"Operation","variables":{},"extensions":null,"query":"query Operation {\\n  \\n}"}',
       );
     });
 
@@ -252,7 +252,7 @@ void main() {
 
       expect(
         captured.body,
-        '{"operationName":null,"variables":{},"extensions":{"extension-1":"extension-value-1"},"query":"{}"}',
+        '{"operationName":null,"variables":{},"extensions":{"extension-1":"extension-value-1"},"query":"query {\\n  \\n}"}',
       );
     });
 
@@ -519,7 +519,7 @@ void main() {
         r'''--dart-http-boundary-REPLACED
 content-disposition: form-data; name="operations"
 
-{"operationName":null,"variables":{"files":[null,null]},"query":"{}"}
+{"operationName":null,"variables":{"files":[null,null]},"query":"query {\n  \n}"}
 --dart-http-boundary-REPLACED
 content-disposition: form-data; name="map"
 

packages/graphql_flutter/README.md

@@ -301,6 +301,14 @@ The syntax for mutations is fairly similar to that of a query. The only differen
 Mutation(
   options: MutationOptions(
     document: addStar, // this is the mutation string you just created
+    // you can update the cache based on results
+    update: (Cache cache, QueryResult result) {
+      return cache;
+    },
+    // or do something with the result.data on completion
+    onCompleted: (dynamic resultData) {
+      print(resultData);
+    },
   ),
   builder: (
     RunMutation runMutation,