Better service resolution by leveraging RequestServices (#1090)

Author: SimonCropp

docs/configuration.md

@@ -72,7 +72,7 @@ A delegate that resolves the DbContext.
 ```cs
 namespace GraphQL.EntityFramework;
 
-public delegate TDbContext ResolveDbContext<out TDbContext>(object userContext)
+public delegate TDbContext ResolveDbContext<out TDbContext>(object userContext, IServiceProvider? requestServices)
     where TDbContext : DbContext;
 ```
 <sup><a href='/src/GraphQL.EntityFramework/GraphApi/ResolveDbContext.cs#L1-L4' title='Snippet source file'>snippet source</a> | <a href='#snippet-ResolveDbContext.cs' title='Start of snippet'>anchor</a></sup>
@@ -298,23 +298,6 @@ public class GraphQlController(ISchema schema, IDocumentExecuter executer) :
 Multiple different DbContext types can be registered and used.
 
 
-### UserContext
-
-A user context that exposes both types.
-
-<!-- snippet: MultiUserContext -->
-<a id='snippet-MultiUserContext'></a>
-```cs
-public class UserContext(DbContext1 context1, DbContext2 context2) : Dictionary<string, object?>
-{
-    public readonly DbContext1 DbContext1 = context1;
-    public readonly DbContext2 DbContext2 = context2;
-}
-```
-<sup><a href='/src/Tests/MultiContextTests/MultiContextTests.cs#L80-L86' title='Snippet source file'>snippet source</a> | <a href='#snippet-MultiUserContext' title='Start of snippet'>anchor</a></sup>
-<!-- endSnippet -->
-
-
 ### Register in container
 
 Register both DbContext types in the container and include how those instance can be extracted from the GraphQL context:
@@ -324,10 +307,10 @@ Register both DbContext types in the container and include how those instance ca
 ```cs
 EfGraphQLConventions.RegisterInContainer(
     services,
-    userContext => ((UserContext) userContext).DbContext1);
+    (_, requestServices) => requestServices!.GetRequiredService<DbContext1>());
 EfGraphQLConventions.RegisterInContainer(
     services,
-    userContext => ((UserContext) userContext).DbContext2);
+    (_, requestServices) => requestServices!.GetRequiredService<DbContext2>());
 ```
 <sup><a href='/src/Tests/MultiContextTests/MultiContextTests.cs#L49-L58' title='Snippet source file'>snippet source</a> | <a href='#snippet-RegisterMultipleInContainer' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
@@ -345,7 +328,7 @@ var executionOptions = new ExecutionOptions
 {
     Schema = schema,
     Query = query,
-    UserContext = new UserContext(dbContext1, dbContext2)
+    RequestServices = provider,
 };
 ```
 <sup><a href='/src/Tests/MultiContextTests/MultiContextTests.cs#L64-L73' title='Snippet source file'>snippet source</a> | <a href='#snippet-MultiExecutionOptions' title='Start of snippet'>anchor</a></sup>
@@ -369,39 +352,23 @@ public class MultiContextQuery :
         efGraphQlService1.AddSingleField(
             graph: this,
             name: "entity1",
-            resolve: context =>
-            {
-                var userContext = (UserContext) context.UserContext;
-                return userContext.DbContext1.Entities;
-            });
+            resolve: _ => _.DbContext.Entities);
         efGraphQlService1.AddFirstField(
             graph: this,
             name: "entity1First",
-            resolve: context =>
-            {
-                var userContext = (UserContext) context.UserContext;
-                return userContext.DbContext1.Entities;
-            });
+            resolve: _ => _.DbContext.Entities);
         efGraphQlService2.AddSingleField(
             graph: this,
             name: "entity2",
-            resolve: context =>
-            {
-                var userContext = (UserContext) context.UserContext;
-                return userContext.DbContext2.Entities;
-            });
+            resolve: _ => _.DbContext.Entities);
         efGraphQlService2.AddFirstField(
             graph: this,
             name: "entity2First",
-            resolve: context =>
-            {
-                var userContext = (UserContext) context.UserContext;
-                return userContext.DbContext2.Entities;
-            });
+            resolve: _ => _.DbContext.Entities);
     }
 }
 ```
-<sup><a href='/src/Tests/MultiContextTests/MultiContextQuery.cs#L1-L41' title='Snippet source file'>snippet source</a> | <a href='#snippet-MultiContextQuery.cs' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Tests/MultiContextTests/MultiContextQuery.cs#L1-L25' title='Snippet source file'>snippet source</a> | <a href='#snippet-MultiContextQuery.cs' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 

docs/mdsource/configuration.source.md

@@ -139,13 +139,6 @@ snippet: GraphQlController
 Multiple different DbContext types can be registered and used.
 
 
-### UserContext
-
-A user context that exposes both types.
-
-snippet: MultiUserContext
-
-
 ### Register in container
 
 Register both DbContext types in the container and include how those instance can be extracted from the GraphQL context:

src/GraphQL.EntityFramework/EfGraphQLConventions.cs

@@ -28,10 +28,8 @@ public static void RegisterInContainer<TDbContext>(
         RegisterScalarsAndArgs(services);
         services.AddHttpContextAccessor();
         services.AddTransient<HttpContextCapture>();
-        services.AddSingleton(
-            provider => Build(resolveDbContext, model, resolveFilters, provider, disableTracking, disableAsync));
-        services.AddSingleton<IEfGraphQLService<TDbContext>>(
-            provider => provider.GetRequiredService<EfGraphQLService<TDbContext>>());
+        services.AddSingleton(provider => Build(resolveDbContext, model, resolveFilters, provider, disableTracking, disableAsync));
+        services.AddSingleton<IEfGraphQLService<TDbContext>>(provider => provider.GetRequiredService<EfGraphQLService<TDbContext>>());
     }
 
     static EfGraphQLService<TDbContext> Build<TDbContext>(
@@ -45,7 +43,7 @@ static EfGraphQLService<TDbContext> Build<TDbContext>(
     {
         model ??= ResolveModel<TDbContext>(provider);
         filters ??= provider.GetService<ResolveFilters<TDbContext>>();
-        dbContextResolver ??= _ => DbContextFromProvider<TDbContext>(provider);
+        dbContextResolver ??= (_, requestServices) => DbContextFromProvider<TDbContext>(provider, requestServices);
 
         return new(
             model,
@@ -55,9 +53,16 @@ static EfGraphQLService<TDbContext> Build<TDbContext>(
             disableAsync);
     }
 
-    static TDbContext DbContextFromProvider<TDbContext>(IServiceProvider provider)
+    static TDbContext DbContextFromProvider<TDbContext>(IServiceProvider provider, IServiceProvider? requestServices)
         where TDbContext : DbContext
     {
+        var dataFromRequestServices = requestServices?
+            .GetService<TDbContext>();
+        if (dataFromRequestServices is not null)
+        {
+            return dataFromRequestServices;
+        }
+
         var dataFromHttpContext = provider.GetService<HttpContextCapture>()?
             .HttpContextAccessor
             .HttpContext?

src/GraphQL.EntityFramework/GraphApi/EfGraphQLService.cs

@@ -65,8 +65,13 @@ ResolveEfFieldContext<TDbContext, TSource> BuildContext<TSource>(
             User = context.User
         };
 
-    public TDbContext ResolveDbContext(IResolveFieldContext context) =>
-        resolveDbContext(context.UserContext);
+    public TDbContext ResolveDbContext(IResolveFieldContext fieldContext)
+    {
+        var userContext = fieldContext.UserContext;
+        var executionContext = fieldContext.ExecutionContext;
+        var requestServices = executionContext.RequestServices ?? executionContext.ExecutionOptions.RequestServices;
+        return resolveDbContext(userContext, requestServices);
+    }
 
     Filters<TDbContext>? ResolveFilter<TSource>(IResolveFieldContext<TSource> context) =>
         resolveFilters?.Invoke(context.UserContext);

src/GraphQL.EntityFramework/GraphApi/ResolveDbContext.cs

@@ -1,4 +1,4 @@
 namespace GraphQL.EntityFramework;
 
-public delegate TDbContext ResolveDbContext<out TDbContext>(object userContext)
+public delegate TDbContext ResolveDbContext<out TDbContext>(object userContext, IServiceProvider? requestServices)
     where TDbContext : DbContext;

src/SampleWeb/Subscription.cs

@@ -101,7 +101,6 @@
 //        {
 //            Document = document,
 //            Schema = schema,
-//            UserContext = new UserContext(dbContext),
 //            Variables = variableValues,
 //            Fragments = document.Fragments,
 //            CancellationToken = token,
@@ -141,7 +140,6 @@
 //            Document = context.Document,
 //            Fragments = context.Fragments,
 //            RootValue = context.RootValue,
-//            UserContext = context.UserContext,
 //            Operation = context.Operation,
 //            Variables = context.Variables,
 //            CancellationToken = context.CancellationToken,

src/SampleWeb/UserContext.cs

@@ -24,16 +24,16 @@ public async Task ExplicitModel()
         services.AddSingleton<DependencySchema>();
         EfGraphQLConventions.RegisterInContainer(
             services,
-            userContext => ((UserContextSingleDb<DependencyDbContext>) userContext).DbContext,
+            (_, _) => dbContext,
             sqlInstance.Model);
         await using var provider = services.BuildServiceProvider();
         using var schema = provider.GetRequiredService<DependencySchema>();
         var executionOptions = new ExecutionOptions
         {
             Schema = schema,
             Query = query,
-            UserContext = new UserContextSingleDb<DependencyDbContext>(dbContext),
-            Variables = null
+            Variables = null,
+            RequestServices = provider
         };
 
         await ExecutionResultData(executionOptions);
@@ -50,15 +50,15 @@ public async Task ScopedDbContext()
 
         EfGraphQLConventions.RegisterInContainer(
             services,
-            userContext => ((UserContextSingleDb<DependencyDbContext>) userContext).DbContext);
+            (_, requestServices) => requestServices!.GetRequiredService<DependencyDbContext>());
         await using var provider = services.BuildServiceProvider();
         using var schema = new DependencySchema(provider);
         var executionOptions = new ExecutionOptions
         {
             Schema = schema,
             Query = query,
-            UserContext = new UserContextSingleDb<DependencyDbContext>(dbContext),
-            Variables = null
+            Variables = null,
+            RequestServices = provider
         };
 
         await ExecutionResultData(executionOptions);
@@ -75,15 +75,15 @@ public async Task TransientDbContext()
 
         EfGraphQLConventions.RegisterInContainer(
             services,
-            userContext => ((UserContextSingleDb<DependencyDbContext>) userContext).DbContext);
+            (_, requestServices) => requestServices!.GetRequiredService<DependencyDbContext>());
         await using var provider = services.BuildServiceProvider();
         using var schema = new DependencySchema(provider);
         var options = new ExecutionOptions
         {
             Schema = schema,
             Query = query,
-            UserContext = new UserContextSingleDb<DependencyDbContext>(dbContext),
-            Variables = null
+            Variables = null,
+            RequestServices = provider
         };
 
         await ExecutionResultData(options);
@@ -100,15 +100,15 @@ public async Task SingletonDbContext()
 
         EfGraphQLConventions.RegisterInContainer(
             services,
-            userContext => ((UserContextSingleDb<DependencyDbContext>) userContext).DbContext);
+            (_, requestServices) => requestServices!.GetRequiredService<DependencyDbContext>());
         await using var provider = services.BuildServiceProvider();
         using var schema = new DependencySchema(provider);
         var options = new ExecutionOptions
         {
             Schema = schema,
             Query = query,
-            UserContext = new UserContextSingleDb<DependencyDbContext>(dbContext),
-            Variables = null
+            Variables = null,
+            RequestServices = provider
         };
 
         await ExecutionResultData(options);

src/Tests/DependencyResolutionTests/DependencyTests.cs

@@ -40,7 +40,7 @@ public async Task SchemaPrint()
             services.AddSingleton(type);
         }
 
-        EfGraphQLConventions.RegisterInContainer(services, _ => dbContext, dbContext.Model);
+        EfGraphQLConventions.RegisterInContainer(services, (_, _) => dbContext, dbContext.Model);
         await using var provider = services.BuildServiceProvider();
         using var schema = new Schema(provider);
 

src/Tests/IntegrationTests/IntegrationTests.cs

@@ -12,7 +12,7 @@ public static async Task<string> ExecuteQuery<TDbContext>(
     {
         EfGraphQLConventions.RegisterInContainer(
             services,
-            _ => data,
+            (_, _) => data,
             data.Model,
             _ => filters,
             disableTracking,
@@ -26,8 +26,8 @@ public static async Task<string> ExecuteQuery<TDbContext>(
             Schema = schema,
             Query = query,
             ThrowOnUnhandledException = true,
-            UserContext = new UserContextSingleDb<TDbContext>(data),
             Variables = inputs,
+            RequestServices = provider,
         };
 
         var result = await executer.ExecuteWithErrorCheck(options);