gin/binding/validate.go

80 lines
1.9 KiB
Go

// Copyright 2014 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 (
"errors"
"reflect"
"strings"
)
func Validate(obj interface{}) error {
return validate(obj, "{{ROOT}}")
}
func validate(obj interface{}, parent string) error {
typ, val := inspectObject(obj)
switch typ.Kind() {
case reflect.Struct:
return validateStruct(typ, val, parent)
case reflect.Slice:
return validateSlice(typ, val, parent)
default:
return errors.New("The object is not a slice or struct.")
}
}
func inspectObject(obj interface{}) (typ reflect.Type, val reflect.Value) {
typ = reflect.TypeOf(obj)
val = reflect.ValueOf(obj)
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
val = val.Elem()
}
return
}
func validateSlice(typ reflect.Type, val reflect.Value, parent string) error {
if typ.Elem().Kind() == reflect.Struct {
for i := 0; i < val.Len(); i++ {
itemValue := val.Index(i).Interface()
if err := validate(itemValue, parent); err != nil {
return err
}
}
}
return nil
}
func validateStruct(typ reflect.Type, val reflect.Value, parent string) error {
for i := 0; i < typ.NumField(); i++ {
field := typ.Field(i)
// Allow ignored and unexported fields in the struct
// TODO should include || field.Tag.Get("form") == "-"
if len(field.PkgPath) > 0 {
continue
}
fieldValue := val.Field(i).Interface()
requiredField := strings.Index(field.Tag.Get("binding"), "required") > -1
if requiredField {
zero := reflect.Zero(field.Type).Interface()
if reflect.DeepEqual(zero, fieldValue) {
return errors.New("Required " + field.Name + " in " + parent)
}
}
fieldType := field.Type.Kind()
if fieldType == reflect.Struct || fieldType == reflect.Slice {
if err := validate(fieldValue, field.Name); err != nil {
return err
}
}
}
return nil
}