Added Singleton and Field to simplify GQL definitions

context.go

@@ -120,6 +120,10 @@ type GQLContext struct {
   ValidLockables ObjTypeMap
   ValidThreads ObjTypeMap
 
+  BaseNodeType *graphql.Object
+  BaseLockableType *graphql.Object
+  BaseThreadType *graphql.Object
+
   Query *graphql.Object
   Mutation *graphql.Object
   Subscription *graphql.Object
@@ -154,6 +158,7 @@ func NewGQLContext() GQLContext {
     Query: query,
     Mutation: mutation,
     Subscription: subscription,
+    BaseNodeType: GQLTypeGraphNode.Type,
   }
 
   return ctx
@@ -168,48 +173,49 @@ func NewContext(db * badger.DB, log Logger) * Context {
     Types: map[uint64]NodeDef{},
   }
 
-  err := ctx.RegisterNodeType(NewNodeDef((*GraphNode)(nil), LoadGraphNode, GQLTypeGraphNode()))
+  err := ctx.RegisterNodeType(NewNodeDef((*GraphNode)(nil), LoadGraphNode, GQLTypeGraphNode.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*SimpleLockable)(nil), LoadSimpleLockable, GQLTypeSimpleLockable()))
+  err = ctx.RegisterNodeType(NewNodeDef((*SimpleLockable)(nil), LoadSimpleLockable, GQLTypeSimpleLockable.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*SimpleThread)(nil), LoadSimpleThread, GQLTypeSimpleThread()))
+  err = ctx.RegisterNodeType(NewNodeDef((*SimpleThread)(nil), LoadSimpleThread, GQLTypeSimpleThread.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*GQLThread)(nil), LoadGQLThread, GQLTypeGQLThread()))
+  err = ctx.RegisterNodeType(NewNodeDef((*GQLThread)(nil), LoadGQLThread, GQLTypeGQLThread.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*User)(nil), LoadUser, GQLTypeUser()))
+  err = ctx.RegisterNodeType(NewNodeDef((*User)(nil), LoadUser, GQLTypeUser.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*PerNodePolicy)(nil), LoadPerNodePolicy, GQLTypeGraphNode()))
+  err = ctx.RegisterNodeType(NewNodeDef((*PerNodePolicy)(nil), LoadPerNodePolicy, GQLTypeGraphNode.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*SimplePolicy)(nil), LoadSimplePolicy, GQLTypeGraphNode()))
+  err = ctx.RegisterNodeType(NewNodeDef((*SimplePolicy)(nil), LoadSimplePolicy, GQLTypeGraphNode.Type))
   if err != nil {
     panic(err)
   }
-  err = ctx.RegisterNodeType(NewNodeDef((*PerTagPolicy)(nil), LoadPerTagPolicy, GQLTypeGraphNode()))
+  err = ctx.RegisterNodeType(NewNodeDef((*PerTagPolicy)(nil), LoadPerTagPolicy, GQLTypeGraphNode.Type))
   if err != nil {
     panic(err)
   }
 
-  ctx.AddGQLType(GQLTypeSignal())
+  ctx.AddGQLType(GQLTypeSignal.Type)
 
-  ctx.GQL.Query.AddFieldConfig("Self", GQLQuerySelf())
+  ctx.GQL.Query.AddFieldConfig("Self", GQLQuerySelf)
+  ctx.GQL.Query.AddFieldConfig("User", GQLQueryUser)
 
-  ctx.GQL.Subscription.AddFieldConfig("Update", GQLSubscriptionUpdate())
-  ctx.GQL.Subscription.AddFieldConfig("Self", GQLSubscriptionSelf())
+  ctx.GQL.Subscription.AddFieldConfig("Update", GQLSubscriptionUpdate)
+  ctx.GQL.Subscription.AddFieldConfig("Self", GQLSubscriptionSelf)
 
-  ctx.GQL.Mutation.AddFieldConfig("sendUpdate", GQLMutationSendUpdate())
-  ctx.GQL.Mutation.AddFieldConfig("startChild", GQLMutationStartChild())
+  ctx.GQL.Mutation.AddFieldConfig("sendUpdate", GQLMutationSendUpdate)
+  ctx.GQL.Mutation.AddFieldConfig("startChild", GQLMutationStartChild)
 
   err = ctx.RebuildSchema()
   if err != nil {

gql_mutation.go

@@ -4,17 +4,15 @@ import (
   "github.com/graphql-go/graphql"
 )
 
-var gql_mutation_send_update *graphql.Field = nil
-func GQLMutationSendUpdate() *graphql.Field {
-  if gql_mutation_send_update == nil {
-    gql_mutation_send_update = &graphql.Field{
-      Type: GQLTypeSignal(),
+var GQLMutationSendUpdate = NewField(func()*graphql.Field {
+  gql_mutation_send_update := &graphql.Field{
+    Type: GQLTypeSignal.Type,
     Args: graphql.FieldConfigArgument{
       "id": &graphql.ArgumentConfig{
         Type: graphql.String,
       },
       "signal": &graphql.ArgumentConfig{
-          Type: GQLTypeSignalInput(),
+        Type: GQLTypeSignalInput.Type,
       },
     },
     Resolve: func(p graphql.ResolveParams) (interface{}, error) {
@@ -65,16 +63,13 @@ func GQLMutationSendUpdate() *graphql.Field {
       return signal, nil
     },
   }
-  }
 
   return gql_mutation_send_update
-}
+})
 
-var gql_mutation_start_child *graphql.Field = nil
-func GQLMutationStartChild() *graphql.Field {
-  if gql_mutation_start_child == nil {
-    gql_mutation_start_child = &graphql.Field{
-      Type: GQLTypeSignal(),
+var GQLMutationStartChild = NewField(func()*graphql.Field{
+  gql_mutation_start_child := &graphql.Field{
+    Type: GQLTypeSignal.Type,
     Args: graphql.FieldConfigArgument{
       "parent_id": &graphql.ArgumentConfig{
         Type: graphql.String,
@@ -132,7 +127,7 @@ func GQLMutationStartChild() *graphql.Field {
       return signal, nil
     },
   }
-  }
 
   return gql_mutation_start_child
-}
+})
+

gql_query.go

@@ -1,30 +1,38 @@
 package graphvent
 import (
-  "fmt"
   "github.com/graphql-go/graphql"
 )
 
-var gql_query_self *graphql.Field = nil
-func GQLQuerySelf() *graphql.Field {
-  if gql_query_self == nil {
-    gql_query_self = &graphql.Field{
-      Type: GQLTypeGQLThread(),
+var GQLQuerySelf = &graphql.Field{
+  Type: GQLTypeGQLThread.Type,
   Resolve: func(p graphql.ResolveParams) (interface{}, error) {
     _, server, user, err := PrepResolve(p)
-
     if err != nil {
       return nil, err
     }
 
     err = server.Allowed("enumerate", "self", user)
     if err != nil {
-          return nil, fmt.Errorf("User %s is not allowed to perform self.enumerate on %s", user.ID(), server.ID())
+      return nil, err
     }
 
     return server, nil
   },
 }
+
+var GQLQueryUser = &graphql.Field{
+  Type: GQLTypeUser.Type,
+  Resolve: func(p graphql.ResolveParams) (interface{}, error) {
+    _, _, user, err := PrepResolve(p)
+    if err != nil {
+      return nil, err
     }
 
-  return gql_query_self
+    err = user.Allowed("enumerate", "self", user)
+    if err != nil {
+      return nil, err
+    }
+
+    return user, nil
+  },
 }

gql_subscribe.go

@@ -50,33 +50,26 @@ func GQLSubscribeFn(p graphql.ResolveParams, send_nil bool, fn func(*Context, *G
   return c, nil
 }
 
-var gql_subscription_self * graphql.Field = nil
-func GQLSubscriptionSelf() * graphql.Field {
-  if gql_subscription_self == nil {
-    gql_subscription_self = &graphql.Field{
-      Type: GQLTypeGQLThread(),
+var GQLSubscriptionSelf = NewField(func()*graphql.Field{
+  gql_subscription_self := &graphql.Field{
+    Type: GQLTypeGQLThread.Type,
     Resolve: func(p graphql.ResolveParams) (interface{}, error) {
       return p.Source, nil
     },
     Subscribe: GQLSubscribeSelf,
   }
-  }
 
   return gql_subscription_self
-}
+})
 
-var gql_subscription_update * graphql.Field = nil
-func GQLSubscriptionUpdate() * graphql.Field {
-  if gql_subscription_update == nil {
-    gql_subscription_update = &graphql.Field{
-      Type: GQLTypeSignal(),
+var GQLSubscriptionUpdate = NewField(func()*graphql.Field{
+  gql_subscription_update := &graphql.Field{
+    Type: GQLTypeSignal.Type,
     Resolve: func(p graphql.ResolveParams) (interface{}, error) {
       return p.Source, nil
     },
     Subscribe: GQLSubscribeSignal,
   }
-  }
-
   return gql_subscription_update
-}
+})
 

gql_test.go

@@ -237,7 +237,7 @@ func TestGQLAuth(t * testing.T) {
 
     url = fmt.Sprintf("https://localhost:%d/gql", port)
     ser, err := json.MarshalIndent(&GQLPayload{
-      Query: "query { Self { Users { ID } } }",
+      Query: "query { Self { Users { ID, Name } } }",
     }, "", "  ")
     fatalErr(t, err)
 

gql_types.go

@@ -5,10 +5,31 @@ import (
   "reflect"
 )
 
-var gql_interface_graph_node *graphql.Interface = nil
-func GQLInterfaceNode() *graphql.Interface {
-  if gql_interface_graph_node == nil {
-    gql_interface_graph_node = graphql.NewInterface(graphql.InterfaceConfig{
+type Field *graphql.Field
+
+func NewField(init func()*graphql.Field) Field {
+  return Field(init())
+}
+
+type Singleton[K graphql.Type] struct {
+  Type K
+  List *graphql.List
+}
+
+func NewSingleton[K graphql.Type](init func() K, post_init func(K, *graphql.List)) *Singleton[K] {
+  val := init()
+  list := graphql.NewList(val)
+  if post_init != nil {
+    post_init(val, list)
+  }
+  return &Singleton[K]{
+    Type: val,
+    List: list,
+  }
+}
+
+var GQLInterfaceNode = NewSingleton(func() *graphql.Interface {
+  i := graphql.NewInterface(graphql.InterfaceConfig{
     Name: "Node",
     ResolveType: func(p graphql.ResolveTypeParams) *graphql.Object {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -27,34 +48,21 @@ func GQLInterfaceNode() *graphql.Interface {
       }
 
       if p_type.Implements(node_type) {
-          return GQLTypeGraphNode()
+        return ctx.GQL.BaseNodeType
       }
 
       return nil
     },
     Fields: graphql.Fields{},
   })
-
-    gql_interface_graph_node.AddFieldConfig("ID", &graphql.Field{
+  i.AddFieldConfig("ID", &graphql.Field{
     Type: graphql.String,
   })
-  }
+  return i
+}, nil)
 
-  return gql_interface_graph_node
-}
-
-var gql_list_thread *graphql.List = nil
-func GQLListThread() *graphql.List {
-  if gql_list_thread == nil {
-    gql_list_thread = graphql.NewList(GQLInterfaceThread())
-  }
-  return gql_list_thread
-}
-
-var gql_interface_thread *graphql.Interface = nil
-func GQLInterfaceThread() *graphql.Interface {
-  if gql_interface_thread == nil {
-    gql_interface_thread = graphql.NewInterface(graphql.InterfaceConfig{
+var GQLInterfaceThread = NewSingleton(func() *graphql.Interface {
+  gql_interface_thread := graphql.NewInterface(graphql.InterfaceConfig{
     Name: "Thread",
     ResolveType: func(p graphql.ResolveTypeParams) *graphql.Object {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -73,7 +81,7 @@ func GQLInterfaceThread() *graphql.Interface {
       }
 
       if p_type.Implements(thread_type) {
-          return GQLTypeSimpleThread()
+        return ctx.GQL.BaseThreadType
       }
 
       ctx.Log.Logf("gql", "Found no type that matches %+v: %+v", p_type, p_type.Implements(thread_type))
@@ -94,42 +102,32 @@ func GQLInterfaceThread() *graphql.Interface {
     Type: graphql.String,
   })
 
-    gql_interface_thread.AddFieldConfig("Children", &graphql.Field{
-      Type: GQLListThread(),
-    })
-
-    gql_interface_thread.AddFieldConfig("Parent", &graphql.Field{
-      Type: GQLInterfaceThread(),
-    })
-
   gql_interface_thread.AddFieldConfig("Requirements", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
   })
 
   gql_interface_thread.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
   })
 
   gql_interface_thread.AddFieldConfig("Owner", &graphql.Field{
-      Type: GQLInterfaceLockable(),
+    Type: GQLInterfaceLockable.Type,
   })
-  }
 
   return gql_interface_thread
-}
+}, func(thread *graphql.Interface, thread_list *graphql.List) {
+  thread.AddFieldConfig("Children", &graphql.Field{
+    Type: thread_list,
+  })
 
-var gql_list_lockable *graphql.List = nil
-func GQLListLockable() *graphql.List {
-  if gql_list_lockable == nil {
-    gql_list_lockable = graphql.NewList(GQLInterfaceLockable())
-  }
-  return gql_list_lockable
-}
+  thread.AddFieldConfig("Parent", &graphql.Field{
+    Type: thread,
+  })
 
-var gql_interface_lockable *graphql.Interface = nil
-func GQLInterfaceLockable() *graphql.Interface {
-  if gql_interface_lockable == nil {
-    gql_interface_lockable = graphql.NewInterface(graphql.InterfaceConfig{
+})
+
+var GQLInterfaceLockable = NewSingleton(func() *graphql.Interface {
+  gql_interface_lockable := graphql.NewInterface(graphql.InterfaceConfig{
     Name: "Lockable",
     ResolveType: func(p graphql.ResolveTypeParams) *graphql.Object {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -148,7 +146,7 @@ func GQLInterfaceLockable() *graphql.Interface {
       }
 
       if p_type.Implements(lockable_type) {
-          return GQLTypeSimpleLockable()
+        return ctx.GQL.BaseThreadType
       }
       return nil
     },
@@ -162,44 +160,27 @@ func GQLInterfaceLockable() *graphql.Interface {
   gql_interface_lockable.AddFieldConfig("Name", &graphql.Field{
     Type: graphql.String,
   })
-
-    if gql_list_lockable == nil {
-      gql_list_lockable = graphql.NewList(gql_interface_lockable)
-    }
-
-    gql_interface_lockable.AddFieldConfig("Requirements", &graphql.Field{
-      Type: gql_list_lockable,
+  return gql_interface_lockable
+}, func(lockable *graphql.Interface, lockable_list *graphql.List) {
+  lockable.AddFieldConfig("Requirements", &graphql.Field{
+    Type: lockable_list,
   })
 
-    gql_interface_lockable.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: gql_list_lockable,
+  lockable.AddFieldConfig("Dependencies", &graphql.Field{
+    Type: lockable_list,
   })
 
-    gql_interface_lockable.AddFieldConfig("Owner", &graphql.Field{
-      Type: gql_interface_lockable,
+  lockable.AddFieldConfig("Owner", &graphql.Field{
+    Type: lockable,
+  })
 })
 
-  }
-
-  return gql_interface_lockable
-}
-
-var gql_list_user *graphql.List = nil
-func GQLListUser() *graphql.List {
-  if gql_list_user == nil {
-    gql_list_user = graphql.NewList(GQLTypeUser())
-  }
-  return gql_list_user
-}
-
-var gql_type_user *graphql.Object = nil
-func GQLTypeUser() * graphql.Object {
-  if gql_type_user == nil {
-    gql_type_user = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeUser = NewSingleton(func() *graphql.Object {
+  gql_type_user := graphql.NewObject(graphql.ObjectConfig{
     Name: "User",
     Interfaces: []*graphql.Interface{
-        GQLInterfaceNode(),
-        GQLInterfaceLockable(),
+      GQLInterfaceNode.Type,
+      GQLInterfaceLockable.Type,
     },
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -230,32 +211,29 @@ func GQLTypeUser() * graphql.Object {
   })
 
   gql_type_user.AddFieldConfig("Requirements", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableRequirements,
   })
 
   gql_type_user.AddFieldConfig("Owner", &graphql.Field{
-      Type: GQLInterfaceLockable(),
+    Type: GQLInterfaceLockable.Type,
     Resolve: GQLLockableOwner,
   })
 
   gql_type_user.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableDependencies,
   })
-  }
   return gql_type_user
-}
+}, nil)
 
-var gql_type_gql_thread *graphql.Object = nil
-func GQLTypeGQLThread() * graphql.Object {
-  if gql_type_gql_thread == nil {
-    gql_type_gql_thread = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeGQLThread = NewSingleton(func() *graphql.Object {
+  gql_type_gql_thread := graphql.NewObject(graphql.ObjectConfig{
     Name: "GQLThread",
     Interfaces: []*graphql.Interface{
-        GQLInterfaceNode(),
-        GQLInterfaceThread(),
-        GQLInterfaceLockable(),
+      GQLInterfaceNode.Type,
+      GQLInterfaceThread.Type,
+      GQLInterfaceLockable.Type,
     },
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       _, ok := p.Value.(*GQLThread)
@@ -280,12 +258,12 @@ func GQLTypeGQLThread() * graphql.Object {
   })
 
   gql_type_gql_thread.AddFieldConfig("Children", &graphql.Field{
-      Type: GQLListThread(),
+    Type: GQLInterfaceThread.List,
     Resolve: GQLThreadChildren,
   })
 
   gql_type_gql_thread.AddFieldConfig("Parent", &graphql.Field{
-      Type: GQLInterfaceThread(),
+    Type: GQLInterfaceThread.Type,
     Resolve: GQLThreadParent,
   })
 
@@ -295,37 +273,34 @@ func GQLTypeGQLThread() * graphql.Object {
   })
 
   gql_type_gql_thread.AddFieldConfig("Requirements", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableRequirements,
   })
 
   gql_type_gql_thread.AddFieldConfig("Owner", &graphql.Field{
-      Type: GQLInterfaceLockable(),
+    Type: GQLInterfaceLockable.Type,
     Resolve: GQLLockableOwner,
   })
 
   gql_type_gql_thread.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableDependencies,
   })
 
   gql_type_gql_thread.AddFieldConfig("Users", &graphql.Field{
-      Type: GQLListUser(),
+    Type: GQLTypeUser.List,
     Resolve: GQLThreadUsers,
   })
-  }
   return gql_type_gql_thread
-}
+}, nil)
 
-var gql_type_simple_thread *graphql.Object = nil
-func GQLTypeSimpleThread() * graphql.Object {
-  if gql_type_simple_thread == nil {
-    gql_type_simple_thread = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeSimpleThread = NewSingleton(func() *graphql.Object {
+  gql_type_simple_thread := graphql.NewObject(graphql.ObjectConfig{
     Name: "SimpleThread",
     Interfaces: []*graphql.Interface{
-        GQLInterfaceNode(),
-        GQLInterfaceThread(),
-        GQLInterfaceLockable(),
+      GQLInterfaceNode.Type,
+      GQLInterfaceThread.Type,
+      GQLInterfaceLockable.Type,
     },
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -361,41 +336,39 @@ func GQLTypeSimpleThread() * graphql.Object {
   })
 
   gql_type_simple_thread.AddFieldConfig("Children", &graphql.Field{
-      Type: GQLListThread(),
+    Type: GQLInterfaceThread.List,
     Resolve: GQLThreadChildren,
   })
 
   gql_type_simple_thread.AddFieldConfig("Parent", &graphql.Field{
-      Type: GQLInterfaceThread(),
+    Type: GQLInterfaceThread.Type,
     Resolve: GQLThreadParent,
   })
 
   gql_type_simple_thread.AddFieldConfig("Requirements", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableRequirements,
   })
 
   gql_type_simple_thread.AddFieldConfig("Owner", &graphql.Field{
-      Type: GQLInterfaceLockable(),
+    Type: GQLInterfaceLockable.Type,
     Resolve: GQLLockableOwner,
   })
 
   gql_type_simple_thread.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableDependencies,
   })
-  }
+
   return gql_type_simple_thread
-}
+}, nil)
 
-var gql_type_simple_lockable *graphql.Object = nil
-func GQLTypeSimpleLockable() * graphql.Object {
-  if gql_type_simple_lockable == nil {
-    gql_type_simple_lockable = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeSimpleLockable = NewSingleton(func() *graphql.Object {
+  gql_type_simple_lockable := graphql.NewObject(graphql.ObjectConfig{
     Name: "SimpleLockable",
     Interfaces: []*graphql.Interface{
-        GQLInterfaceNode(),
-        GQLInterfaceLockable(),
+      GQLInterfaceNode.Type,
+      GQLInterfaceLockable.Type,
     },
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -426,30 +399,28 @@ func GQLTypeSimpleLockable() * graphql.Object {
   })
 
   gql_type_simple_lockable.AddFieldConfig("Requirements", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableRequirements,
   })
 
   gql_type_simple_lockable.AddFieldConfig("Owner", &graphql.Field{
-      Type: GQLInterfaceLockable(),
+    Type: GQLInterfaceLockable.Type,
     Resolve: GQLLockableOwner,
   })
 
   gql_type_simple_lockable.AddFieldConfig("Dependencies", &graphql.Field{
-      Type: GQLListLockable(),
+    Type: GQLInterfaceLockable.List,
     Resolve: GQLLockableDependencies,
   })
-  }
+
   return gql_type_simple_lockable
-}
+}, nil)
 
-var gql_type_simple_node *graphql.Object = nil
-func GQLTypeGraphNode() * graphql.Object {
-  if gql_type_simple_node == nil {
-    gql_type_simple_node = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeGraphNode = NewSingleton(func() *graphql.Object {
+  object := graphql.NewObject(graphql.ObjectConfig{
     Name: "GraphNode",
     Interfaces: []*graphql.Interface{
-        GQLInterfaceNode(),
+      GQLInterfaceNode.Type,
     },
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       ctx, ok := p.Context.Value("graph_context").(*Context)
@@ -469,24 +440,21 @@ func GQLTypeGraphNode() * graphql.Object {
     Fields: graphql.Fields{},
   })
 
-    gql_type_simple_node.AddFieldConfig("ID", &graphql.Field{
+  object.AddFieldConfig("ID", &graphql.Field{
     Type: graphql.String,
     Resolve: GQLNodeID,
   })
 
-    gql_type_simple_node.AddFieldConfig("Name", &graphql.Field{
+  object.AddFieldConfig("Name", &graphql.Field{
     Type: graphql.String,
     Resolve: GQLLockableName,
   })
-  }
 
-  return gql_type_simple_node
-}
+  return object
+}, nil)
 
-var gql_type_signal *graphql.Object = nil
-func GQLTypeSignal() *graphql.Object {
-  if gql_type_signal == nil {
-    gql_type_signal = graphql.NewObject(graphql.ObjectConfig{
+var GQLTypeSignal = NewSingleton(func() *graphql.Object {
+  gql_type_signal := graphql.NewObject(graphql.ObjectConfig{
     Name: "SignalOut",
     IsTypeOf: func(p graphql.IsTypeOfParams) bool {
       _, ok := p.Value.(GraphSignal)
@@ -511,14 +479,11 @@ func GQLTypeSignal() *graphql.Object {
     Type: graphql.String,
     Resolve: GQLSignalString,
   })
-  }
   return gql_type_signal
-}
+}, nil)
 
-var gql_type_signal_input *graphql.InputObject = nil
-func GQLTypeSignalInput() *graphql.InputObject {
-  if gql_type_signal_input == nil {
-    gql_type_signal_input = graphql.NewInputObject(graphql.InputObjectConfig{
+var GQLTypeSignalInput = NewSingleton(func()*graphql.InputObject {
+  gql_type_signal_input := graphql.NewInputObject(graphql.InputObjectConfig{
     Name: "SignalIn",
     Fields: graphql.InputObjectConfigFieldMap{},
   })
@@ -530,7 +495,7 @@ func GQLTypeSignalInput() *graphql.InputObject {
     Type: graphql.String,
     DefaultValue: "down",
   })
-  }
+
   return gql_type_signal_input
-}
+}, nil)
 

node.go

@@ -101,6 +101,12 @@ func (node * GraphNode) Serialize() ([]byte, error) {
 }
 
 func (node *GraphNode) Allowed(action string, resource string, principal Node) error {
+  if principal == nil {
+    return fmt.Errorf("nil is not allowed to perform any actions")
+  }
+  if node.ID() == principal.ID() {
+    return nil
+  }
   for _, policy := range(node.policies) {
     if policy.Allows(action, resource, principal) == true {
       return nil