Fix docs (#2722)

* docs: fix variable names in dataloader sample

* fix: request-scoped middleware

docs/content/reference/dataloaders.md

@@ -138,11 +138,12 @@ func NewLoaders(conn *sql.DB) *Loaders {
 
 // Middleware injects data loaders into the context
 func Middleware(conn *sql.DB, next http.Handler) http.Handler {
-	// create a request-scoped data loader
-	loader := NewLoaders(conn)
 	// return a middleware that injects the loader to the request context
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		nextCtx := context.WithValue(r.Context(), loadersKey, loaders)
+		// create a request-scoped data loader
+		loader := NewLoaders(conn)
+		// inject to context
+		nextCtx := context.WithValue(r.Context(), loadersKey, loader)
 		r = r.WithContext(nextCtx)
 		next.ServeHTTP(w, r)
 	})
@@ -155,8 +156,8 @@ func For(ctx context.Context) *Loaders {
 
 // GetUser wraps the User dataloader for efficient retrieval by user ID
 func GetUser(ctx context.Context, userID string) (*model.User, error) {
-	loaders := For(ctx)
-	thunk := loaders.UserLoader.Load(ctx, dataloader.StringKey(userID))
+	loader := For(ctx)
+	thunk := loader.UserLoader.Load(ctx, dataloader.StringKey(userID))
 	result, err := thunk()
 	if err != nil {
 		return nil, err