Generate FieldMiddleware

Moves it off of RequestContext and into generated land.  This change
has a basic implementation of how directive middlewares might work.

codegen/directive.go

@@ -3,9 +3,9 @@ package codegen
 import "strings"
 
 type Directive struct {
-	name string
+	Name string
 }
 
-func (d *Directive) Name() string {
-	return strings.Title(d.name)
+func (d *Directive) GoName() string {
+	return strings.Title(d.Name)
 }

codegen/directive_build.go

@@ -6,7 +6,7 @@ func (cfg *Config) buildDirectives() (directives []*Directive) {
 			continue
 		}
 		directives = append(directives, &Directive{
-			name: name,
+			Name: name,
 		})
 	}
 	return directives

codegen/templates/generated.gotpl

@@ -31,7 +31,7 @@ type ResolverRoot interface {
 
 type DirectiveRoot struct {
 {{ range $directive := .Directives }}
-	{{$directive.Name}} graphql.FieldMiddleware
+	{{$directive.GoName}} graphql.FieldMiddleware
 {{ end }}
 }
 
@@ -56,7 +56,7 @@ func (e *executableSchema) Schema() *ast.Schema {
 
 func (e *executableSchema) Query(ctx context.Context, op *ast.OperationDefinition) *graphql.Response {
 	{{- if .QueryRoot }}
-		ec := executionContext{graphql.GetRequestContext(ctx), e.resolvers}
+		ec := executionContext{graphql.GetRequestContext(ctx), e}
 
 		buf := ec.RequestMiddleware(ctx, func(ctx context.Context) []byte {
 			data := ec._{{.QueryRoot.GQLType}}(ctx, op.SelectionSet)
@@ -76,7 +76,7 @@ func (e *executableSchema) Query(ctx context.Context, op *ast.OperationDefinitio
 
 func (e *executableSchema) Mutation(ctx context.Context, op *ast.OperationDefinition) *graphql.Response {
 	{{- if .MutationRoot }}
-		ec := executionContext{graphql.GetRequestContext(ctx), e.resolvers}
+		ec := executionContext{graphql.GetRequestContext(ctx), e}
 
 		buf := ec.RequestMiddleware(ctx, func(ctx context.Context) []byte {
 			data := ec._{{.MutationRoot.GQLType}}(ctx, op.SelectionSet)
@@ -96,7 +96,7 @@ func (e *executableSchema) Mutation(ctx context.Context, op *ast.OperationDefini
 
 func (e *executableSchema) Subscription(ctx context.Context, op *ast.OperationDefinition) func() *graphql.Response {
 	{{- if .SubscriptionRoot }}
-		ec := executionContext{graphql.GetRequestContext(ctx), e.resolvers}
+		ec := executionContext{graphql.GetRequestContext(ctx), e}
 
 		next := ec._{{.SubscriptionRoot.GQLType}}(ctx, op.SelectionSet)
 		if ec.Errors != nil {
@@ -128,8 +128,7 @@ func (e *executableSchema) Subscription(ctx context.Context, op *ast.OperationDe
 
 type executionContext struct {
 	*graphql.RequestContext
-
-	resolvers ResolverRoot
+	*executableSchema
 }
 
 {{- range $object := .Objects }}
@@ -148,6 +147,30 @@ type executionContext struct {
 	{{ template "input.gotpl" $input }}
 {{- end }}
 
+func (ec *executionContext) FieldMiddleware(ctx context.Context, next graphql.Resolver) interface{} {
+	{{- if .Directives }}
+	rctx := graphql.GetResolverContext(ctx)
+	if len(rctx.Field.Directives) != 0 {
+		for _, d := range rctx.Field.Directives {
+			switch d.Name {
+			{{- range $directive := .Directives }}
+			case "{{$directive.Name}}":
+				next = func(ctx context.Context) (interface{}, error) {
+					return ec.directives.{{$directive.GoName}}(ctx, next)
+				}
+			{{- end }}
+			}
+		}
+	}
+	{{- end }}
+	res, err := ec.ResolverMiddleware(ctx, next)
+	if err != nil {
+		ec.Error(ctx, err)
+		return nil
+	}
+	return res
+}
+
 func (ec *executionContext) introspectSchema() *introspection.Schema {
 	return introspection.WrapSchema(parsedSchema)
 }

graphql/context.go

@@ -41,15 +41,6 @@ func DefaultRequestMiddleware(ctx context.Context, next func(ctx context.Context
 	return next(ctx)
 }
 
-func (c *RequestContext) FieldMiddleware(ctx context.Context, next Resolver) interface{} {
-	res, err := c.ResolverMiddleware(ctx, next)
-	if err != nil {
-		c.Error(ctx, err)
-		return nil
-	}
-	return res
-}
-
 func NewRequestContext(doc *ast.QueryDocument, query string, variables map[string]interface{}) *RequestContext {
 	return &RequestContext{
 		Doc:                 doc,