💯Go Struct and Field validation, including Cross Field, Cross Struct, Map, Slice and Array diving
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validator/validator_instance.go

447 lines
12 KiB

package validator
import (
"errors"
"fmt"
"reflect"
"strings"
"sync"
"time"
)
const (
defaultTagName = "validate"
utf8HexComma = "0x2C"
utf8Pipe = "0x7C"
tagSeparator = ","
orSeparator = "|"
tagKeySeparator = "="
structOnlyTag = "structonly"
noStructLevelTag = "nostructlevel"
omitempty = "omitempty"
skipValidationTag = "-"
diveTag = "dive"
namespaceSeparator = "."
leftBracket = "["
rightBracket = "]"
restrictedTagChars = ".[],|=+()`~!@#$%^&*\\\"/?<>{}"
restrictedAliasErr = "Alias '%s' either contains restricted characters or is the same as a restricted tag needed for normal operation"
restrictedTagErr = "Tag '%s' either contains restricted characters or is the same as a restricted tag needed for normal operation"
)
var (
timeType = reflect.TypeOf(time.Time{})
defaultCField = new(cField)
)
// CustomTypeFunc allows for overriding or adding custom field type handler functions
// field = field value of the type to return a value to be validated
// example Valuer from sql drive see https://golang.org/src/database/sql/driver/types.go?s=1210:1293#L29
type CustomTypeFunc func(field reflect.Value) interface{}
// TagNameFunc allows for adding of a custom tag name parser
type TagNameFunc func(field reflect.StructField) string
// Validate contains the validator settings and cache
type Validate struct {
tagName string
pool *sync.Pool
hasCustomFuncs bool
hasTagNameFunc bool
tagNameFunc TagNameFunc
structLevelFuncs map[reflect.Type]StructLevelFunc
customFuncs map[reflect.Type]CustomTypeFunc
aliases map[string]string
validations map[string]Func
tagCache *tagCache
structCache *structCache
}
// New returns a new instacne of 'validate' with sane defaults.
func New() *Validate {
tc := new(tagCache)
tc.m.Store(make(map[string]*cTag))
sc := new(structCache)
sc.m.Store(make(map[reflect.Type]*cStruct))
v := &Validate{
tagName: defaultTagName,
aliases: make(map[string]string, len(bakedInAliases)),
validations: make(map[string]Func, len(bakedInValidators)),
tagCache: tc,
structCache: sc,
}
// must copy alias validators for separate validations to be used in each validator instance
for k, val := range bakedInAliases {
v.RegisterAlias(k, val)
}
// must copy validators for separate validations to be used in each instance
for k, val := range bakedInValidators {
// no need to error check here, baked in will alwaays be valid
v.RegisterValidation(k, val)
}
v.pool = &sync.Pool{
New: func() interface{} {
return &validate{
v: v,
errs: make(ValidationErrors, 0, 4),
}
},
}
return v
}
// SetTagName allows for changing of the default tag name of 'validate'
func (v *Validate) SetTagName(name string) {
v.tagName = name
}
// RegisterTagNameFunc registers a function to get another name from the
// StructField eg. the JSON name
func (v *Validate) RegisterTagNameFunc(fn TagNameFunc) {
v.tagNameFunc = fn
v.hasTagNameFunc = true
}
// RegisterValidation adds a validation with the given tag
//
// NOTES:
// - if the key already exists, the previous validation function will be replaced.
// - this method is not thread-safe it is intended that these all be registered prior to any validation
func (v *Validate) RegisterValidation(tag string, fn Func) error {
if len(tag) == 0 {
return errors.New("Function Key cannot be empty")
}
if fn == nil {
return errors.New("Function cannot be empty")
}
_, ok := restrictedTags[tag]
if ok || strings.ContainsAny(tag, restrictedTagChars) {
panic(fmt.Sprintf(restrictedTagErr, tag))
}
v.validations[tag] = fn
return nil
}
// RegisterAlias registers a mapping of a single validation tag that
// defines a common or complex set of validation(s) to simplify adding validation
// to structs.
//
// NOTE: this function is not thread-safe it is intended that these all be registered prior to any validation
func (v *Validate) RegisterAlias(alias, tags string) {
_, ok := restrictedTags[alias]
if ok || strings.ContainsAny(alias, restrictedTagChars) {
panic(fmt.Sprintf(restrictedAliasErr, alias))
}
v.aliases[alias] = tags
}
// RegisterStructValidation registers a StructLevelFunc against a number of types.
// This is akin to implementing the 'Validatable' interface, but for structs for which
// you may not have access or rights to change.
//
// NOTES:
// - if this and the 'Validatable' interface are implemented the Struct Level takes precedence as to enable
// a struct out of your control's validation to be overridden
// - this method is not thread-safe it is intended that these all be registered prior to any validation
func (v *Validate) RegisterStructValidation(fn StructLevelFunc, types ...interface{}) {
if v.structLevelFuncs == nil {
v.structLevelFuncs = make(map[reflect.Type]StructLevelFunc)
}
for _, t := range types {
v.structLevelFuncs[reflect.TypeOf(t)] = fn
}
}
// RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types
//
// NOTE: this method is not thread-safe it is intended that these all be registered prior to any validation
func (v *Validate) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{}) {
if v.customFuncs == nil {
v.customFuncs = make(map[reflect.Type]CustomTypeFunc)
}
for _, t := range types {
v.customFuncs[reflect.TypeOf(t)] = fn
}
v.hasCustomFuncs = true
}
// Struct validates a structs exposed fields, and automatically validates nested structs, unless otherwise specified.
//
// It returns InvalidValidationError for bad values passed in and nil or ValidationErrors as error otherwise.
// You will need to assert the error if it's not nil eg. err.(validator.ValidationErrors) to access the array of errors.
func (v *Validate) Struct(s interface{}) (err error) {
val := reflect.ValueOf(s)
top := val
if val.Kind() == reflect.Ptr && !val.IsNil() {
val = val.Elem()
}
if val.Kind() != reflect.Struct || val.Type() == timeType {
return &InvalidValidationError{Type: reflect.TypeOf(s)}
}
// good to validate
vd := v.pool.Get().(*validate)
vd.top = top
vd.isPartial = false
// vd.hasExcludes = false // only need to reset in StructPartial and StructExcept
vd.validateStruct(top, val, val.Type(), vd.ns[0:0], vd.actualNs[0:0], nil)
if len(vd.errs) > 0 {
err = vd.errs
vd.errs = nil
}
v.pool.Put(vd)
return
}
// StructPartial validates the fields passed in only, ignoring all others.
// Fields may be provided in a namespaced fashion relative to the struct provided
// eg. NestedStruct.Field or NestedArrayField[0].Struct.Name
//
// It returns InvalidValidationError for bad values passed in and nil or ValidationErrors as error otherwise.
// You will need to assert the error if it's not nil eg. err.(validator.ValidationErrors) to access the array of errors.
func (v *Validate) StructPartial(s interface{}, fields ...string) (err error) {
val := reflect.ValueOf(s)
top := val
if val.Kind() == reflect.Ptr && !val.IsNil() {
val = val.Elem()
}
if val.Kind() != reflect.Struct || val.Type() == timeType {
return &InvalidValidationError{Type: reflect.TypeOf(s)}
}
// good to validate
vd := v.pool.Get().(*validate)
vd.top = top
vd.isPartial = true
vd.hasExcludes = false
vd.includeExclude = make(map[string]struct{})
typ := val.Type()
name := typ.Name()
if fields != nil {
for _, k := range fields {
flds := strings.Split(k, namespaceSeparator)
if len(flds) > 0 {
key := name + namespaceSeparator
for _, s := range flds {
idx := strings.Index(s, leftBracket)
if idx != -1 {
for idx != -1 {
key += s[:idx]
vd.includeExclude[key] = struct{}{}
idx2 := strings.Index(s, rightBracket)
idx2++
key += s[idx:idx2]
vd.includeExclude[key] = struct{}{}
s = s[idx2:]
idx = strings.Index(s, leftBracket)
}
} else {
key += s
vd.includeExclude[key] = struct{}{}
}
key += namespaceSeparator
}
}
}
}
vd.validateStruct(top, val, typ, vd.ns[0:0], vd.actualNs[0:0], nil)
if len(vd.errs) > 0 {
err = vd.errs
vd.errs = nil
}
v.pool.Put(vd)
return
}
// StructExcept validates all fields except the ones passed in.
// Fields may be provided in a namespaced fashion relative to the struct provided
// i.e. NestedStruct.Field or NestedArrayField[0].Struct.Name
//
// It returns InvalidValidationError for bad values passed in and nil or ValidationErrors as error otherwise.
// You will need to assert the error if it's not nil eg. err.(validator.ValidationErrors) to access the array of errors.
func (v *Validate) StructExcept(s interface{}, fields ...string) (err error) {
val := reflect.ValueOf(s)
top := val
if val.Kind() == reflect.Ptr && !val.IsNil() {
val = val.Elem()
}
if val.Kind() != reflect.Struct || val.Type() == timeType {
return &InvalidValidationError{Type: reflect.TypeOf(s)}
}
// good to validate
vd := v.pool.Get().(*validate)
vd.top = top
vd.isPartial = true
vd.hasExcludes = true
vd.includeExclude = make(map[string]struct{})
typ := val.Type()
name := typ.Name()
for _, key := range fields {
vd.includeExclude[name+namespaceSeparator+key] = struct{}{}
}
vd.validateStruct(top, val, typ, vd.ns[0:0], vd.actualNs[0:0], nil)
if len(vd.errs) > 0 {
err = vd.errs
vd.errs = nil
}
v.pool.Put(vd)
return
}
// Var validates a single variable using tag style validation.
// eg.
// var i int
// validate.Var(i, "gt=1,lt=10")
//
// WARNING: a struct can be passed for validation eg. time.Time is a struct or if you have a custom type and have registered
// a custom type handler, so must allow it; however unforseen validations will occur if trying to validate a struct
// that is meant to be passed to 'validate.Struct'
//
// It returns InvalidValidationError for bad values passed in and nil or ValidationErrors as error otherwise.
// You will need to assert the error if it's not nil eg. err.(validator.ValidationErrors) to access the array of errors.
// validate Array, Slice and maps fields which may contain more than one error
func (v *Validate) Var(field interface{}, tag string) (err error) {
if len(tag) == 0 || tag == skipValidationTag {
return nil
}
// find cached tag
ctag, ok := v.tagCache.Get(tag)
if !ok {
v.tagCache.lock.Lock()
defer v.tagCache.lock.Unlock()
// could have been multiple trying to access, but once first is done this ensures tag
// isn't parsed again.
ctag, ok = v.tagCache.Get(tag)
if !ok {
ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false)
v.tagCache.Set(tag, ctag)
}
}
val := reflect.ValueOf(field)
vd := v.pool.Get().(*validate)
vd.top = val
vd.isPartial = false
vd.traverseField(val, val, vd.ns[0:0], vd.actualNs[0:0], defaultCField, ctag)
if len(vd.errs) > 0 {
err = vd.errs
vd.errs = nil
}
v.pool.Put(vd)
return
}
// VarWithValue validates a single variable, against another variable/field's value using tag style validation
// eg.
// s1 := "abcd"
// s2 := "abcd"
// validate.VarWithValue(s1, s2, "eqcsfield") // returns true
//
// WARNING: a struct can be passed for validation eg. time.Time is a struct or if you have a custom type and have registered
// a custom type handler, so must allow it; however unforseen validations will occur if trying to validate a struct
// that is meant to be passed to 'validate.Struct'
//
// It returns InvalidValidationError for bad values passed in and nil or ValidationErrors as error otherwise.
// You will need to assert the error if it's not nil eg. err.(validator.ValidationErrors) to access the array of errors.
// validate Array, Slice and maps fields which may contain more than one error
func (v *Validate) VarWithValue(field interface{}, other interface{}, tag string) (err error) {
if len(tag) == 0 || tag == skipValidationTag {
return nil
}
// find cached tag
ctag, ok := v.tagCache.Get(tag)
if !ok {
v.tagCache.lock.Lock()
defer v.tagCache.lock.Unlock()
// could have been multiple trying to access, but once first is done this ensures tag
// isn't parsed again.
ctag, ok = v.tagCache.Get(tag)
if !ok {
ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false)
v.tagCache.Set(tag, ctag)
}
}
otherVal := reflect.ValueOf(other)
vd := v.pool.Get().(*validate)
vd.top = otherVal
vd.isPartial = false
vd.traverseField(otherVal, reflect.ValueOf(field), vd.ns[0:0], vd.actualNs[0:0], defaultCField, ctag)
if len(vd.errs) > 0 {
err = vd.errs
vd.errs = nil
}
v.pool.Put(vd)
return
}