Improve CustomValidator code

Add missing headers and fix Validator duplicating error messages

Author: jrschumacher

website/content/guide/request.md

@@ -84,6 +84,16 @@ a custom validator using `Echo#Validator` and leverage third-party [libraries](h
 Example below uses https://github.com/go-playground/validator framework for validation:
 
 ```go
+package main
+
+import (
+  "net/http"
+  
+	"github.com/go-playground/validator"
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
+
 type (
   User struct {
     Name  string `json:"name" validate:"required"`
@@ -97,7 +107,8 @@ type (
 
 func (cv *CustomValidator) Validate(i interface{}) error {
   if err := cv.validator.Struct(i); err != nil {
-    return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+    // Optionally, you could return the error to give each route more control over the status code
+    return echo.NewHTTPError(http.StatusBadRequest, err.Error())
   }
   return nil
 }
@@ -111,7 +122,7 @@ func main() {
       return echo.NewHTTPError(http.StatusBadRequest, err.Error())
     }
     if err = c.Validate(u); err != nil {
-      return echo.NewHTTPError(http.StatusBadRequest, err.Error())
+      return err
     }
     return c.JSON(http.StatusOK, u)
   })