Revert "improve gin support (deepmap#530)"

This reverts commit f10cd14.

It caused a breaking change to existing users.

pkg/codegen/templates/gin/gin-register.tmpl

@@ -1,26 +1,21 @@
 // GinServerOptions provides options for the Gin server.
 type GinServerOptions struct {
     BaseURL string
-    Middlewares []gin.HandlerFunc
+    Middlewares []MiddlewareFunc
 }
 
-// keeping for backward compatibility
-type MiddlewareFunc = gin.HandlerFunc
-
 // RegisterHandlers creates http.Handler with routing matching OpenAPI spec.
-func RegisterHandlers(router gin.IRouter, si ServerInterface) gin.IRouter {
+func RegisterHandlers(router *gin.Engine, si ServerInterface) *gin.Engine {
   return RegisterHandlersWithOptions(router, si, GinServerOptions{})
 }
 
 // RegisterHandlersWithOptions creates http.Handler with additional options
-func RegisterHandlersWithOptions(router gin.IRouter, si ServerInterface, options GinServerOptions) gin.IRouter {
+func RegisterHandlersWithOptions(router *gin.Engine, si ServerInterface, options GinServerOptions) *gin.Engine {
 {{if .}}wrapper := ServerInterfaceWrapper{
 Handler: si,
+HandlerMiddlewares: options.Middlewares,
 }
 {{end}}
-
-router = router.Group("/", options.Middlewares...)
-
 {{range .}}
 router.{{.Method }}(options.BaseURL+"{{.Path | swaggerUriToGinUri }}", wrapper.{{.OperationId}})
 {{end}}

pkg/codegen/templates/gin/gin-wrappers.tmpl

@@ -1,8 +1,11 @@
 // ServerInterfaceWrapper converts contexts to parameters.
 type ServerInterfaceWrapper struct {
     Handler ServerInterface
+    HandlerMiddlewares []MiddlewareFunc
 }
 
+type MiddlewareFunc func(c *gin.Context)
+
 {{range .}}{{$opid := .OperationId}}
 
 // {{$opid}} operation middleware
@@ -162,6 +165,10 @@ func (siw *ServerInterfaceWrapper) {{$opid}}(c *gin.Context) {
     {{end}}
   {{end}}
 
+  for _, middleware := range siw.HandlerMiddlewares {
+    middleware(c)
+  }
+
   siw.Handler.{{.OperationId}}(c{{genParamNames .PathParams}}{{if .RequiresParamObject}}, params{{end}})
 }
 {{end}}

pkg/gin-middleware/oapi_validate.go

@@ -72,8 +72,6 @@ func OapiRequestValidatorWithOptions(swagger *openapi3.T, options *Options) gin.
 		err := ValidateRequestFromContext(c, router, options)
 		if err != nil {
 			// note: i am not sure if this is the best way to handle this
-			// todo: the error message should be customizable by the user
-			c.Error(err)
 			c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		}
 		c.Next()
@@ -126,9 +124,6 @@ func ValidateRequestFromContext(c *gin.Context, router routers.Router, options *
 			errorLines := strings.Split(e.Error(), "\n")
 			return fmt.Errorf("error in openapi3filter.RequestError: %s", errorLines[0])
 		case *openapi3filter.SecurityRequirementsError:
-			for _, e := range e.Errors {
-				c.Error(e)
-			}
 			return fmt.Errorf("error in openapi3filter.SecurityRequirementsError: %s", e.Error())
 		default:
 			// This should never happen today, but if our upstream code changes,