Merge pull request zino-hofmann#398 from micimize/client_defaults

Client-level default policies

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

@@ -41,25 +41,47 @@ enum ErrorPolicy {
   all,
 }
 
+class Policies {
+  /// Specifies the [FetchPolicy] to be used.
+  FetchPolicy fetch;
+
+  /// Specifies the [ErrorPolicy] to be used.
+  ErrorPolicy error;
+  Policies({
+    this.fetch,
+    this.error,
+  });
+
+  Policies.safe(
+    this.fetch,
+    this.error,
+  )   : assert(fetch != null, 'fetch policy must be specified'),
+        assert(error != null, 'error policy must be specified');
+
+  Policies withOverrides([Policies overrides]) => Policies.safe(
+        overrides?.fetch ?? fetch,
+        overrides?.error ?? error,
+      );
+}
+
 /// Base options.
 class BaseOptions extends RawOperationData {
   BaseOptions({
     @required String document,
     Map<String, dynamic> variables,
-    this.fetchPolicy,
-    this.errorPolicy,
+    this.policies,
     this.context,
     this.optimisticResult,
   }) : super(document: document, variables: variables);
 
   /// An optimistic result to eagerly add to the operation stream
   Object optimisticResult;
 
-  /// Specifies the [FetchPolicy] to be used.
-  FetchPolicy fetchPolicy;
+  /// Specifies the [Policies] to be used during execution.
+  Policies policies;
 
-  /// Specifies the [ErrorPolicy] to be used.
-  ErrorPolicy errorPolicy;
+  FetchPolicy get fetchPolicy => policies.fetch;
+  ErrorPolicy get errorPolicy => policies.error;
 
   /// Context to be passed to link execution chain.
   Map<String, dynamic> context;
@@ -76,10 +98,9 @@ class QueryOptions extends BaseOptions {
     this.pollInterval,
     Map<String, dynamic> context,
   }) : super(
+          policies: Policies(fetch: fetchPolicy, error: errorPolicy),
           document: document,
           variables: variables,
-          fetchPolicy: fetchPolicy,
-          errorPolicy: errorPolicy,
           context: context,
           optimisticResult: optimisticResult,
         );
@@ -98,10 +119,9 @@ class MutationOptions extends BaseOptions {
     ErrorPolicy errorPolicy = ErrorPolicy.none,
     Map<String, dynamic> context,
   }) : super(
+          policies: Policies(fetch: fetchPolicy, error: errorPolicy),
           document: document,
           variables: variables,
-          fetchPolicy: fetchPolicy,
-          errorPolicy: errorPolicy,
           context: context,
         );
 }
@@ -148,11 +168,7 @@ class WatchQueryOptions extends QueryOptions {
       return true;
     }
 
-    if (a.fetchPolicy != b.fetchPolicy) {
-      return true;
-    }
-
-    if (a.errorPolicy != b.errorPolicy) {
+    if (a.policies != b.policies) {
       return true;
     }
 

packages/graphql/lib/src/graphql_client.dart

@@ -10,20 +10,79 @@ import 'package:graphql/src/link/link.dart';
 import 'package:graphql/src/link/operation.dart';
 import 'package:meta/meta.dart';
 
+/// The default [Policies] to set for each client action
+class DefaultPolicies {
+  /// The default [Policies] for watchQuery.
+  /// Defaults to
+  /// ```
+  /// Policies(
+  ///   FetchPolicy.cacheAndNetwork,
+  ///   ErrorPolicy.none,
+  /// )
+  /// ```
+  Policies watchQuery;
+
+  /// The default [Policies] for query.
+  /// Defaults to
+  /// ```
+  /// Policies(
+  ///   FetchPolicy.cacheFirst,
+  ///   ErrorPolicy.none,
+  /// )
+  /// ```
+  Policies query;
+
+  /// The default [Policies] for mutate.
+  /// Defaults to
+  /// ```
+  /// Policies(
+  ///   FetchPolicy.networkOnly,
+  ///   ErrorPolicy.none,
+  /// )
+  /// ```
+  Policies mutate;
+  DefaultPolicies({
+    Policies watchQuery,
+    Policies query,
+    Policies mutate,
+  })  : this.watchQuery = _watchQueryDefaults.withOverrides(watchQuery),
+        this.query = _queryDefaults.withOverrides(query),
+        this.mutate = _mutateDefaults.withOverrides(mutate);
+
+  static final _watchQueryDefaults = Policies.safe(
+    FetchPolicy.cacheAndNetwork,
+    ErrorPolicy.none,
+  );
+
+  static final _queryDefaults = Policies.safe(
+    FetchPolicy.cacheFirst,
+    ErrorPolicy.none,
+  );
+  static final _mutateDefaults = Policies.safe(
+    FetchPolicy.networkOnly,
+    ErrorPolicy.none,
+  );
+}
+
 /// The link is a [Link] over which GraphQL documents will be resolved into a [FetchResult].
 /// The cache is the initial [Cache] to use in the data store.
 class GraphQLClient {
   /// Constructs a [GraphQLClient] given a [Link] and a [Cache].
   GraphQLClient({
     @required this.link,
     @required this.cache,
+    this.defaultPolicies,
   }) {
+    defaultPolicies ??= DefaultPolicies();
     queryManager = QueryManager(
       link: link,
       cache: cache,
     );
   }
 
+  /// The default [Policies] to set for each client action
+  DefaultPolicies defaultPolicies;
+
   /// The [Link] over which GraphQL documents will be resolved into a [FetchResult].
   final Link link;
 
@@ -35,18 +94,22 @@ class GraphQLClient {
   /// This registers a query in the [QueryManager] and returns an [ObservableQuery]
   /// based on the provided [WatchQueryOptions].
   ObservableQuery watchQuery(WatchQueryOptions options) {
+    options.policies =
+        defaultPolicies.watchQuery.withOverrides(options.policies);
     return queryManager.watchQuery(options);
   }
 
   /// This resolves a single query according to the [QueryOptions] specified and
   /// returns a [Future] which resolves with the [QueryResult] or throws an [Exception].
   Future<QueryResult> query(QueryOptions options) {
+    options.policies = defaultPolicies.query.withOverrides(options.policies);
     return queryManager.query(options);
   }
 
   /// This resolves a single mutation according to the [MutationOptions] specified and
   /// returns a [Future] which resolves with the [QueryResult] or throws an [Exception].
   Future<QueryResult> mutate(MutationOptions options) {
+    options.policies = defaultPolicies.mutate.withOverrides(options.policies);
     return queryManager.mutate(options);
   }
 

packages/graphql_flutter/lib/src/widgets/query.dart

@@ -36,21 +36,17 @@ class QueryState extends State<Query> {
   ObservableQuery observableQuery;
 
   WatchQueryOptions get _options {
-    FetchPolicy fetchPolicy = widget.options.fetchPolicy;
-
-    if (fetchPolicy == FetchPolicy.cacheFirst) {
-      fetchPolicy = FetchPolicy.cacheAndNetwork;
-    }
+    final QueryOptions options = widget.options;
 
     return WatchQueryOptions(
-      document: widget.options.document,
-      variables: widget.options.variables,
-      fetchPolicy: fetchPolicy,
-      errorPolicy: widget.options.errorPolicy,
-      pollInterval: widget.options.pollInterval,
+      document: options.document,
+      variables: options.variables,
+      fetchPolicy: options.fetchPolicy,
+      errorPolicy: options.errorPolicy,
+      pollInterval: options.pollInterval,
       fetchResults: true,
-      context: widget.options.context,
-      optimisticResult: widget.options.optimisticResult,
+      context: options.context,
+      optimisticResult: options.optimisticResult,
     );
   }