Merge pull request #152 from movio/request-middleware

Add WrapGraphQLClientTransport to Plugin API

client.go

@@ -27,6 +27,10 @@ type ClientOpt func(*GraphQLClient)
 
 // NewClient creates a new GraphQLClient from the given options.
 func NewClient(opts ...ClientOpt) *GraphQLClient {
+	return NewClientWithPlugins(nil, opts...)
+}
+
+func NewClientWithPlugins(plugins []Plugin, opts ...ClientOpt) *GraphQLClient {
 	c := &GraphQLClient{
 		HTTPClient: &http.Client{
 			Timeout: 5 * time.Second,
@@ -38,6 +42,9 @@ func NewClient(opts ...ClientOpt) *GraphQLClient {
 		opt(c)
 	}
 
+	for _, plugin := range plugins {
+		c.HTTPClient.Transport = plugin.WrapGraphQLClientTransport(c.HTTPClient.Transport)
+	}
 	return c
 }
 

config.go

@@ -271,7 +271,7 @@ func (c *Config) Init() error {
 	if c.QueryHTTPClient != nil {
 		queryClientOptions = append(queryClientOptions, WithHTTPClient(c.QueryHTTPClient))
 	}
-	queryClient := NewClient(queryClientOptions...)
+	queryClient := NewClientWithPlugins(c.plugins, queryClientOptions...)
 	es := NewExecutableSchema(c.plugins, c.MaxRequestsPerQuery, queryClient, services...)
 	err = es.UpdateSchema(true)
 	if err != nil {

execution.go

@@ -21,7 +21,7 @@ func NewExecutableSchema(plugins []Plugin, maxRequestsPerQuery int64, client *Gr
 	}
 
 	if client == nil {
-		client = NewClient()
+		client = NewClientWithPlugins(plugins)
 	}
 
 	return &ExecutableSchema{
@@ -138,6 +138,10 @@ func (s *ExecutableSchema) ExecuteQuery(ctx context.Context) *graphql.Response {
 	operation := operationCtx.Operation
 	variables := operationCtx.Variables
 
+	for _, plugin := range s.plugins {
+		plugin.InterceptRequest(ctx, operation.Name, operationCtx.RawQuery, variables)
+	}
+
 	AddField(ctx, "operation.name", operation.Name)
 	AddField(ctx, "operation.type", operation.Operation)
 

plugin.go

@@ -1,6 +1,7 @@
 package bramble
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
 
@@ -24,6 +25,9 @@ type Plugin interface {
 	GraphqlQueryPath() (bool, string)
 	ApplyMiddlewarePublicMux(http.Handler) http.Handler
 	ApplyMiddlewarePrivateMux(http.Handler) http.Handler
+	WrapGraphQLClientTransport(http.RoundTripper) http.RoundTripper
+
+	InterceptRequest(ctx context.Context, operationName, rawQuery string, variables map[string]interface{})
 }
 
 // BasePlugin is an empty plugin. It can be embedded by any plugin as a way to avoid
@@ -49,6 +53,11 @@ func (p *BasePlugin) GraphqlQueryPath() (bool, string) {
 	return false, ""
 }
 
+// InterceptRequest is called before bramble starts executing a request.
+// It can be used to inspect the unmarshalled GraphQL request bramble receives.
+func (p *BasePlugin) InterceptRequest(ctx context.Context, operationName, rawQuery string, variables map[string]interface{}) {
+}
+
 // ApplyMiddlewarePublicMux ...
 func (p *BasePlugin) ApplyMiddlewarePublicMux(h http.Handler) http.Handler {
 	return h
@@ -59,6 +68,11 @@ func (p *BasePlugin) ApplyMiddlewarePrivateMux(h http.Handler) http.Handler {
 	return h
 }
 
+// WrapGraphQLClientTransport wraps the http.RoundTripper used for GraphQL requests.
+func (p *BasePlugin) WrapGraphQLClientTransport(transport http.RoundTripper) http.RoundTripper {
+	return transport
+}
+
 var registeredPlugins = map[string]Plugin{}
 
 // RegisterPlugin register a plugin so that it can be enabled via the configuration.