add godocs for https://github.com/kataras/iris/issues/1589

core/router/api_builder.go

@@ -957,6 +957,7 @@ func (api *APIBuilder) UseError(handlers ...context.Handler) {
 // If it's called after the routes then these handlers will never be executed.
 // Use `UseGlobal` if you want to register begin handlers(middleware)
 // that should be always run before all application's routes.
+// To register a middleware for error handlers, look `UseError` method instead.
 func (api *APIBuilder) Use(handlers ...context.Handler) {
 	api.middleware = append(api.middleware, handlers...)
 }
@@ -964,6 +965,7 @@ func (api *APIBuilder) Use(handlers ...context.Handler) {
 // UseOnce either inserts a middleware,
 // or on the basis of the middleware already existing,
 // replace that existing middleware instead.
+// To register a middleware for error handlers, look `UseError` method instead.
 func (api *APIBuilder) UseOnce(handlers ...context.Handler) {
 	api.middleware = context.UpsertHandlers(api.middleware, handlers)
 }

core/router/party.go

@@ -102,10 +102,12 @@ type Party interface {
 	UseError(handlers ...context.Handler)
 	// Use appends Handler(s) to the current Party's routes and child routes.
 	// If the current Party is the root, then it registers the middleware to all child Parties' routes too.
+	// To register a middleware for error handlers, look `UseError` method instead.
 	Use(middleware ...context.Handler)
 	// UseOnce either inserts a middleware,
 	// or on the basis of the middleware already existing,
 	// replace that existing middleware instead.
+	// To register a middleware for error handlers, look `UseError` method instead.
 	UseOnce(handlers ...context.Handler)
 	// Done appends to the very end, Handler(s) to the current Party's routes and child routes.
 	// The difference from .Use is that this/or these Handler(s) are being always running last.