gin/binding/default_validator.go
edebernis 57ede9c95a
Export struct sliceValidateError to allow error casting and rename it as (#2777)
SliceValidationError

Co-authored-by: Emeric de Bernis <emeric.debernis@adevinta.com>
2021-11-21 21:45:03 +08:00

98 lines
2.3 KiB
Go

// Copyright 2017 Manu Martinez-Almeida. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.
package binding
import (
"fmt"
"reflect"
"strings"
"sync"
"github.com/go-playground/validator/v10"
)
type defaultValidator struct {
once sync.Once
validate *validator.Validate
}
type SliceValidationError []error
// Error concatenates all error elements in SliceValidationError into a single string separated by \n.
func (err SliceValidationError) Error() string {
n := len(err)
switch n {
case 0:
return ""
default:
var b strings.Builder
if err[0] != nil {
fmt.Fprintf(&b, "[%d]: %s", 0, err[0].Error())
}
if n > 1 {
for i := 1; i < n; i++ {
if err[i] != nil {
b.WriteString("\n")
fmt.Fprintf(&b, "[%d]: %s", i, err[i].Error())
}
}
}
return b.String()
}
}
var _ StructValidator = &defaultValidator{}
// ValidateStruct receives any kind of type, but only performed struct or pointer to struct type.
func (v *defaultValidator) ValidateStruct(obj interface{}) error {
if obj == nil {
return nil
}
value := reflect.ValueOf(obj)
switch value.Kind() {
case reflect.Ptr:
return v.ValidateStruct(value.Elem().Interface())
case reflect.Struct:
return v.validateStruct(obj)
case reflect.Slice, reflect.Array:
count := value.Len()
validateRet := make(SliceValidationError, 0)
for i := 0; i < count; i++ {
if err := v.ValidateStruct(value.Index(i).Interface()); err != nil {
validateRet = append(validateRet, err)
}
}
if len(validateRet) == 0 {
return nil
}
return validateRet
default:
return nil
}
}
// validateStruct receives struct type
func (v *defaultValidator) validateStruct(obj interface{}) error {
v.lazyinit()
return v.validate.Struct(obj)
}
// Engine returns the underlying validator engine which powers the default
// Validator instance. This is useful if you want to register custom validations
// or struct level validations. See validator GoDoc for more info -
// https://pkg.go.dev/github.com/go-playground/validator/v10
func (v *defaultValidator) Engine() interface{} {
v.lazyinit()
return v.validate
}
func (v *defaultValidator) lazyinit() {
v.once.Do(func() {
v.validate = validator.New()
v.validate.SetTagName("binding")
})
}