ots/vendor/gopkg.in/validator.v2/validator.go
Knut Ahlers 3acde1749b
Update dependencies
Signed-off-by: Knut Ahlers <knut@ahlers.me>
2018-05-05 16:57:47 +02:00

370 lines
10 KiB
Go

// Package validator implements value validations
//
// Copyright 2014 Roberto Teixeira <robteix@robteix.com>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validator
import (
"errors"
"fmt"
"reflect"
"regexp"
"strings"
"unicode"
)
// TextErr is an error that also implements the TextMarshaller interface for
// serializing out to various plain text encodings. Packages creating their
// own custom errors should use TextErr if they're intending to use serializing
// formats like json, msgpack etc.
type TextErr struct {
Err error
}
// Error implements the error interface.
func (t TextErr) Error() string {
return t.Err.Error()
}
// MarshalText implements the TextMarshaller
func (t TextErr) MarshalText() ([]byte, error) {
return []byte(t.Err.Error()), nil
}
var (
// ErrZeroValue is the error returned when variable has zero valud
// and nonzero was specified
ErrZeroValue = TextErr{errors.New("zero value")}
// ErrMin is the error returned when variable is less than mininum
// value specified
ErrMin = TextErr{errors.New("less than min")}
// ErrMax is the error returned when variable is more than
// maximum specified
ErrMax = TextErr{errors.New("greater than max")}
// ErrLen is the error returned when length is not equal to
// param specified
ErrLen = TextErr{errors.New("invalid length")}
// ErrRegexp is the error returned when the value does not
// match the provided regular expression parameter
ErrRegexp = TextErr{errors.New("regular expression mismatch")}
// ErrUnsupported is the error error returned when a validation rule
// is used with an unsupported variable type
ErrUnsupported = TextErr{errors.New("unsupported type")}
// ErrBadParameter is the error returned when an invalid parameter
// is provided to a validation rule (e.g. a string where an int was
// expected (max=foo,len=bar) or missing a parameter when one is required (len=))
ErrBadParameter = TextErr{errors.New("bad parameter")}
// ErrUnknownTag is the error returned when an unknown tag is found
ErrUnknownTag = TextErr{errors.New("unknown tag")}
// ErrInvalid is the error returned when variable is invalid
// (normally a nil pointer)
ErrInvalid = TextErr{errors.New("invalid value")}
)
// ErrorMap is a map which contains all errors from validating a struct.
type ErrorMap map[string]ErrorArray
// ErrorMap implements the Error interface so we can check error against nil.
// The returned error is if existent the first error which was added to the map.
func (err ErrorMap) Error() string {
for k, errs := range err {
if len(errs) > 0 {
return fmt.Sprintf("%s: %s", k, errs.Error())
}
}
return ""
}
// ErrorArray is a slice of errors returned by the Validate function.
type ErrorArray []error
// ErrorArray implements the Error interface and returns the first error as
// string if existent.
func (err ErrorArray) Error() string {
if len(err) > 0 {
return err[0].Error()
}
return ""
}
// ValidationFunc is a function that receives the value of a
// field and a parameter used for the respective validation tag.
type ValidationFunc func(v interface{}, param string) error
// Validator implements a validator
type Validator struct {
// Tag name being used.
tagName string
// validationFuncs is a map of ValidationFuncs indexed
// by their name.
validationFuncs map[string]ValidationFunc
}
// Helper validator so users can use the
// functions directly from the package
var defaultValidator = NewValidator()
// NewValidator creates a new Validator
func NewValidator() *Validator {
return &Validator{
tagName: "validate",
validationFuncs: map[string]ValidationFunc{
"nonzero": nonzero,
"len": length,
"min": min,
"max": max,
"regexp": regex,
},
}
}
// SetTag allows you to change the tag name used in structs
func SetTag(tag string) {
defaultValidator.SetTag(tag)
}
// SetTag allows you to change the tag name used in structs
func (mv *Validator) SetTag(tag string) {
mv.tagName = tag
}
// WithTag creates a new Validator with the new tag name. It is
// useful to chain-call with Validate so we don't change the tag
// name permanently: validator.WithTag("foo").Validate(t)
func WithTag(tag string) *Validator {
return defaultValidator.WithTag(tag)
}
// WithTag creates a new Validator with the new tag name. It is
// useful to chain-call with Validate so we don't change the tag
// name permanently: validator.WithTag("foo").Validate(t)
func (mv *Validator) WithTag(tag string) *Validator {
v := mv.copy()
v.SetTag(tag)
return v
}
// Copy a validator
func (mv *Validator) copy() *Validator {
newFuncs := map[string]ValidationFunc{}
for k, f := range mv.validationFuncs {
newFuncs[k] = f
}
return &Validator{
tagName: mv.tagName,
validationFuncs: newFuncs,
}
}
// SetValidationFunc sets the function to be used for a given
// validation constraint. Calling this function with nil vf
// is the same as removing the constraint function from the list.
func SetValidationFunc(name string, vf ValidationFunc) error {
return defaultValidator.SetValidationFunc(name, vf)
}
// SetValidationFunc sets the function to be used for a given
// validation constraint. Calling this function with nil vf
// is the same as removing the constraint function from the list.
func (mv *Validator) SetValidationFunc(name string, vf ValidationFunc) error {
if name == "" {
return errors.New("name cannot be empty")
}
if vf == nil {
delete(mv.validationFuncs, name)
return nil
}
mv.validationFuncs[name] = vf
return nil
}
// Validate validates the fields of a struct based
// on 'validator' tags and returns errors found indexed
// by the field name.
func Validate(v interface{}) error {
return defaultValidator.Validate(v)
}
// Validate validates the fields of a struct based
// on 'validator' tags and returns errors found indexed
// by the field name.
func (mv *Validator) Validate(v interface{}) error {
sv := reflect.ValueOf(v)
st := reflect.TypeOf(v)
if sv.Kind() == reflect.Ptr && !sv.IsNil() {
return mv.Validate(sv.Elem().Interface())
}
if sv.Kind() != reflect.Struct && sv.Kind() != reflect.Interface {
return ErrUnsupported
}
nfields := sv.NumField()
m := make(ErrorMap)
for i := 0; i < nfields; i++ {
fname := st.Field(i).Name
if !unicode.IsUpper(rune(fname[0])) {
continue
}
f := sv.Field(i)
// deal with pointers
for f.Kind() == reflect.Ptr && !f.IsNil() {
f = f.Elem()
}
tag := st.Field(i).Tag.Get(mv.tagName)
if tag == "-" {
continue
}
var errs ErrorArray
if tag != "" {
err := mv.Valid(f.Interface(), tag)
if errors, ok := err.(ErrorArray); ok {
errs = errors
} else {
if err != nil {
errs = ErrorArray{err}
}
}
}
mv.deepValidateCollection(f, fname, m) // no-op if field is not a struct, interface, array, slice or map
if len(errs) > 0 {
m[st.Field(i).Name] = errs
}
}
if len(m) > 0 {
return m
}
return nil
}
func (mv *Validator) deepValidateCollection(f reflect.Value, fname string, m ErrorMap) {
switch f.Kind() {
case reflect.Struct, reflect.Interface, reflect.Ptr:
e := mv.Validate(f.Interface())
if e, ok := e.(ErrorMap); ok && len(e) > 0 {
for j, k := range e {
m[fname+"."+j] = k
}
}
case reflect.Array, reflect.Slice:
for i := 0; i < f.Len(); i++ {
mv.deepValidateCollection(f.Index(i), fmt.Sprintf("%s[%d]", fname, i), m)
}
case reflect.Map:
for _, key := range f.MapKeys() {
mv.deepValidateCollection(key, fmt.Sprintf("%s[%+v](key)", fname, key.Interface()), m) // validate the map key
value := f.MapIndex(key)
mv.deepValidateCollection(value, fmt.Sprintf("%s[%+v](value)", fname, key.Interface()), m)
}
}
}
// Valid validates a value based on the provided
// tags and returns errors found or nil.
func Valid(val interface{}, tags string) error {
return defaultValidator.Valid(val, tags)
}
// Valid validates a value based on the provided
// tags and returns errors found or nil.
func (mv *Validator) Valid(val interface{}, tags string) error {
if tags == "-" {
return nil
}
v := reflect.ValueOf(val)
if v.Kind() == reflect.Ptr && !v.IsNil() {
return mv.Valid(v.Elem().Interface(), tags)
}
var err error
switch v.Kind() {
case reflect.Invalid:
err = mv.validateVar(nil, tags)
default:
err = mv.validateVar(val, tags)
}
return err
}
// validateVar validates one single variable
func (mv *Validator) validateVar(v interface{}, tag string) error {
tags, err := mv.parseTags(tag)
if err != nil {
// unknown tag found, give up.
return err
}
errs := make(ErrorArray, 0, len(tags))
for _, t := range tags {
if err := t.Fn(v, t.Param); err != nil {
errs = append(errs, err)
}
}
if len(errs) > 0 {
return errs
}
return nil
}
// tag represents one of the tag items
type tag struct {
Name string // name of the tag
Fn ValidationFunc // validation function to call
Param string // parameter to send to the validation function
}
// separate by no escaped commas
var sepPattern *regexp.Regexp = regexp.MustCompile(`((?:^|[^\\])(?:\\\\)*),`)
func splitUnescapedComma(str string) []string {
ret := []string{}
indexes := sepPattern.FindAllStringIndex(str, -1)
last := 0
for _, is := range indexes {
ret = append(ret, str[last:is[1]-1])
last = is[1]
}
ret = append(ret, str[last:])
return ret
}
// parseTags parses all individual tags found within a struct tag.
func (mv *Validator) parseTags(t string) ([]tag, error) {
tl := splitUnescapedComma(t)
tags := make([]tag, 0, len(tl))
for _, i := range tl {
i = strings.Replace(i, `\,`, ",", -1)
tg := tag{}
v := strings.SplitN(i, "=", 2)
tg.Name = strings.Trim(v[0], " ")
if tg.Name == "" {
return []tag{}, ErrUnknownTag
}
if len(v) > 1 {
tg.Param = strings.Trim(v[1], " ")
}
var found bool
if tg.Fn, found = mv.validationFuncs[tg.Name]; !found {
return []tag{}, ErrUnknownTag
}
tags = append(tags, tg)
}
return tags, nil
}