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

316 lines
8.0 KiB

package validator
import (
"fmt"
"reflect"
"strconv"
"strings"
)
const (
blank = ""
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 (
restrictedTags = map[string]*struct{}{
diveTag: emptyStructPtr,
existsTag: emptyStructPtr,
structOnlyTag: emptyStructPtr,
omitempty: emptyStructPtr,
skipValidationTag: emptyStructPtr,
utf8HexComma: emptyStructPtr,
utf8Pipe: emptyStructPtr,
}
)
// ExtractType gets the actual underlying type of field value.
// It will dive into pointers, customTypes and return you the
// underlying value and it's kind.
// it is exposed for use within you Custom Functions
func (v *Validate) ExtractType(current reflect.Value) (reflect.Value, reflect.Kind) {
switch current.Kind() {
case reflect.Ptr:
if current.IsNil() {
return current, reflect.Ptr
}
return v.ExtractType(current.Elem())
case reflect.Interface:
if current.IsNil() {
return current, reflect.Interface
}
return v.ExtractType(current.Elem())
case reflect.Invalid:
return current, reflect.Invalid
default:
if v.hasCustomFuncs {
if fn, ok := v.customTypeFuncs[current.Type()]; ok {
return v.ExtractType(reflect.ValueOf(fn(current)))
}
}
return current, current.Kind()
}
}
// GetStructFieldOK traverses a struct to retrieve a specific field denoted by the provided namespace and
// returns the field, field kind and whether is was successful in retrieving the field at all.
// NOTE: when not successful ok will be false, this can happen when a nested struct is nil and so the field
// could not be retrived because it didnt exist.
func (v *Validate) GetStructFieldOK(current reflect.Value, namespace string) (reflect.Value, reflect.Kind, bool) {
current, kind := v.ExtractType(current)
if kind == reflect.Invalid {
return current, kind, false
}
if len(namespace) == 0 {
return current, kind, true
}
switch kind {
case reflect.Ptr, reflect.Interface:
return current, kind, false
case reflect.Struct:
typ := current.Type()
fld := namespace
ns := namespace
if typ != timeType && typ != timePtrType {
idx := strings.Index(namespace, namespaceSeparator)
if idx != -1 {
fld = namespace[:idx]
ns = namespace[idx+1:]
} else {
ns = blank
idx = len(namespace)
}
bracketIdx := strings.Index(fld, leftBracket)
if bracketIdx != -1 {
fld = fld[:bracketIdx]
ns = namespace[bracketIdx:]
}
current = current.FieldByName(fld)
return v.GetStructFieldOK(current, ns)
}
case reflect.Array, reflect.Slice:
idx := strings.Index(namespace, leftBracket)
idx2 := strings.Index(namespace, rightBracket)
arrIdx, _ := strconv.Atoi(namespace[idx+1 : idx2])
if arrIdx >= current.Len() {
return current, kind, false
}
startIdx := idx2 + 1
if startIdx < len(namespace) {
if namespace[startIdx:startIdx+1] == namespaceSeparator {
startIdx++
}
}
return v.GetStructFieldOK(current.Index(arrIdx), namespace[startIdx:])
case reflect.Map:
idx := strings.Index(namespace, leftBracket) + 1
idx2 := strings.Index(namespace, rightBracket)
endIdx := idx2
if endIdx+1 < len(namespace) {
if namespace[endIdx+1:endIdx+2] == namespaceSeparator {
endIdx++
}
}
key := namespace[idx:idx2]
switch current.Type().Key().Kind() {
case reflect.Int:
i, _ := strconv.Atoi(key)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(i)), namespace[endIdx+1:])
case reflect.Int8:
i, _ := strconv.ParseInt(key, 10, 8)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(int8(i))), namespace[endIdx+1:])
case reflect.Int16:
i, _ := strconv.ParseInt(key, 10, 16)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(int16(i))), namespace[endIdx+1:])
case reflect.Int32:
i, _ := strconv.ParseInt(key, 10, 32)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(int32(i))), namespace[endIdx+1:])
case reflect.Int64:
i, _ := strconv.ParseInt(key, 10, 64)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(i)), namespace[endIdx+1:])
case reflect.Uint:
i, _ := strconv.ParseUint(key, 10, 0)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(uint(i))), namespace[endIdx+1:])
case reflect.Uint8:
i, _ := strconv.ParseUint(key, 10, 8)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(uint8(i))), namespace[endIdx+1:])
case reflect.Uint16:
i, _ := strconv.ParseUint(key, 10, 16)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(uint16(i))), namespace[endIdx+1:])
case reflect.Uint32:
i, _ := strconv.ParseUint(key, 10, 32)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(uint32(i))), namespace[endIdx+1:])
case reflect.Uint64:
i, _ := strconv.ParseUint(key, 10, 64)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(i)), namespace[endIdx+1:])
case reflect.Float32:
f, _ := strconv.ParseFloat(key, 32)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(float32(f))), namespace[endIdx+1:])
case reflect.Float64:
f, _ := strconv.ParseFloat(key, 64)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(f)), namespace[endIdx+1:])
case reflect.Bool:
b, _ := strconv.ParseBool(key)
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(b)), namespace[endIdx+1:])
// reflect.Type = string
default:
return v.GetStructFieldOK(current.MapIndex(reflect.ValueOf(key)), namespace[endIdx+1:])
}
}
// if got here there was more namespace, cannot go any deeper
panic("Invalid field namespace")
}
// asInt retuns the parameter as a int64
// or panics if it can't convert
func asInt(param string) int64 {
i, err := strconv.ParseInt(param, 0, 64)
panicIf(err)
return i
}
// asUint returns the parameter as a uint64
// or panics if it can't convert
func asUint(param string) uint64 {
i, err := strconv.ParseUint(param, 0, 64)
panicIf(err)
return i
}
// asFloat returns the parameter as a float64
// or panics if it can't convert
func asFloat(param string) float64 {
i, err := strconv.ParseFloat(param, 64)
panicIf(err)
return i
}
func panicIf(err error) {
if err != nil {
panic(err.Error())
}
}
func (v *Validate) parseTags(tag, fieldName string) *cachedTag {
cTag := &cachedTag{}
v.parseTagsRecursive(cTag, tag, fieldName, blank, false)
return cTag
}
func (v *Validate) parseTagsRecursive(cTag *cachedTag, tag, fieldName, alias string, isAlias bool) bool {
if len(tag) == 0 {
return true
}
for _, t := range strings.Split(tag, tagSeparator) {
if v.hasAliasValidators {
// check map for alias and process new tags, otherwise process as usual
if tagsVal, ok := v.aliasValidators[t]; ok {
leave := v.parseTagsRecursive(cTag, tagsVal, fieldName, t, true)
if leave {
return leave
}
continue
}
}
if t == diveTag {
cTag.diveTag = tag
tVals := &tagVals{tagVals: [][]string{{t}}}
cTag.tags = append(cTag.tags, tVals)
return true
}
if t == omitempty {
cTag.isOmitEmpty = true
}
// if a pipe character is needed within the param you must use the utf8Pipe representation "0x7C"
orVals := strings.Split(t, orSeparator)
tagVal := &tagVals{isAlias: isAlias, isOrVal: len(orVals) > 1, tagVals: make([][]string, len(orVals))}
cTag.tags = append(cTag.tags, tagVal)
var key string
var param string
for i, val := range orVals {
vals := strings.SplitN(val, tagKeySeparator, 2)
key = vals[0]
tagVal.tag = key
if isAlias {
tagVal.tag = alias
}
if len(key) == 0 {
panic(strings.TrimSpace(fmt.Sprintf(invalidValidation, fieldName)))
}
if len(vals) > 1 {
param = strings.Replace(strings.Replace(vals[1], utf8HexComma, ",", -1), utf8Pipe, "|", -1)
}
tagVal.tagVals[i] = []string{key, param}
}
}
return false
}