622 lines
15 KiB
Go
622 lines
15 KiB
Go
package reflect
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import (
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"errors"
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"fmt"
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"net/url"
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"reflect"
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"regexp"
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"strings"
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"time"
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)
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// ErrInvalidParam specifies invalid url query params
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var ErrInvalidParam = errors.New("invalid url query param provided")
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// var timeKind = reflect.ValueOf(time.Time{}).Kind()
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// bracketSplitter
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var bracketSplitter = regexp.MustCompile(`\[|\]`)
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// StructField contains struct field path its value and field
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type StructField struct {
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Value reflect.Value
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Path string
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Field reflect.StructField
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}
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// StructFieldByTag get struct field by tag key and its value
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func StructFieldByTag(src interface{}, tkey string, tval string) (interface{}, error) {
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sv := reflect.ValueOf(src)
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if sv.Kind() == reflect.Ptr {
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sv = sv.Elem()
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}
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if sv.Kind() != reflect.Struct {
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return nil, ErrInvalidStruct
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}
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typ := sv.Type()
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for idx := 0; idx < typ.NumField(); idx++ {
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fld := typ.Field(idx)
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val := sv.Field(idx)
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if len(fld.PkgPath) != 0 {
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continue
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}
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if ts, ok := fld.Tag.Lookup(tkey); ok {
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for _, p := range strings.Split(ts, ",") {
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if p == tval {
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if val.Kind() != reflect.Ptr && val.CanAddr() {
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val = val.Addr()
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}
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return val.Interface(), nil
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}
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}
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}
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switch val.Kind() {
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case reflect.Ptr:
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if val = val.Elem(); val.Kind() == reflect.Struct {
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if iface, err := StructFieldByTag(val.Interface(), tkey, tval); err == nil {
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return iface, nil
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}
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}
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case reflect.Struct:
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if iface, err := StructFieldByTag(val.Interface(), tkey, tval); err == nil {
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return iface, nil
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}
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}
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}
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return nil, ErrNotFound
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}
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// ZeroFieldByPath clean struct field by its path
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func ZeroFieldByPath(src interface{}, path string) error {
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var err error
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val := reflect.ValueOf(src)
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for _, p := range strings.Split(path, ".") {
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val, err = structValueByName(val, p)
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if err != nil {
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return err
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}
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}
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if IsEmpty(val) {
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return nil
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}
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if !val.CanSet() {
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return ErrInvalidStruct
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}
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val.Set(reflect.Zero(val.Type()))
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return nil
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}
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// SetFieldByPath set struct field by its path
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func SetFieldByPath(src interface{}, dst interface{}, path string) error {
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var err error
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val := reflect.ValueOf(src)
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for _, p := range strings.Split(path, ".") {
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val, err = structValueByName(val, p)
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if err != nil {
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return err
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}
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}
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if !val.CanSet() {
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return ErrInvalidStruct
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}
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val.Set(reflect.ValueOf(dst))
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return nil
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}
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// structValueByName get struct field by its name
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func structValueByName(sv reflect.Value, tkey string) (reflect.Value, error) {
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if sv.Kind() == reflect.Ptr {
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sv = sv.Elem()
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}
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if sv.Kind() != reflect.Struct {
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return reflect.Zero(reflect.TypeOf(sv)), ErrInvalidStruct
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}
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typ := sv.Type()
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for idx := 0; idx < typ.NumField(); idx++ {
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fld := typ.Field(idx)
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val := sv.Field(idx)
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if len(fld.PkgPath) != 0 {
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continue
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}
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if fld.Name == tkey || strings.EqualFold(strings.ToLower(fld.Name), strings.ToLower(tkey)) {
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return val, nil
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}
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switch val.Kind() {
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case reflect.Ptr:
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if val = val.Elem(); val.Kind() == reflect.Struct {
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if iface, err := structValueByName(val, tkey); err == nil {
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return iface, nil
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}
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}
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case reflect.Struct:
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if iface, err := structValueByName(val, tkey); err == nil {
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return iface, nil
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}
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}
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}
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return reflect.Zero(reflect.TypeOf(sv)), ErrNotFound
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}
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// StructFieldByPath get struct field by its path
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func StructFieldByPath(src interface{}, path string) (interface{}, error) {
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var err error
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for _, p := range strings.Split(path, ".") {
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src, err = StructFieldByName(src, p)
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if err != nil {
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return nil, err
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}
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}
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return src, err
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}
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// StructFieldByName get struct field by its name
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func StructFieldByName(src interface{}, tkey string) (interface{}, error) {
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sv := reflect.ValueOf(src)
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if sv.Kind() == reflect.Ptr {
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sv = sv.Elem()
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}
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if sv.Kind() != reflect.Struct {
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return nil, ErrInvalidStruct
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}
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typ := sv.Type()
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for idx := 0; idx < typ.NumField(); idx++ {
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fld := typ.Field(idx)
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val := sv.Field(idx)
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if len(fld.PkgPath) != 0 {
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continue
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}
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if fld.Name == tkey || strings.EqualFold(strings.ToLower(fld.Name), strings.ToLower(tkey)) {
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return val.Interface(), nil
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}
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switch val.Kind() {
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case reflect.Ptr:
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if val = val.Elem(); val.Kind() == reflect.Struct {
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if iface, err := StructFieldByName(val.Interface(), tkey); err == nil {
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return iface, nil
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}
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}
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case reflect.Struct:
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if iface, err := StructFieldByName(val.Interface(), tkey); err == nil {
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return iface, nil
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}
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}
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}
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return nil, ErrNotFound
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}
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// StructFieldsMap returns struct map[string]interface{} or error
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func StructFieldsMap(src interface{}) (map[string]interface{}, error) {
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fields, err := StructFields(src)
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if err != nil {
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return nil, err
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}
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mp := make(map[string]interface{}, len(fields))
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for _, field := range fields {
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mp[field.Path] = field.Value.Interface()
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}
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return mp, nil
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}
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// StructFields returns slice of struct fields
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func StructFields(src interface{}) ([]StructField, error) {
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var fields []StructField
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sv := reflect.ValueOf(src)
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if sv.Kind() == reflect.Ptr {
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sv = sv.Elem()
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}
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if sv.Kind() != reflect.Struct {
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return nil, ErrInvalidStruct
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}
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typ := sv.Type()
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for idx := 0; idx < typ.NumField(); idx++ {
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fld := typ.Field(idx)
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val := sv.Field(idx)
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if !val.IsValid() || len(fld.PkgPath) != 0 {
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continue
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}
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switch val.Interface().(type) {
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case time.Time, *time.Time:
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fields = append(fields, StructField{Field: fld, Value: val, Path: fld.Name})
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continue
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case time.Duration, *time.Duration:
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fields = append(fields, StructField{Field: fld, Value: val, Path: fld.Name})
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continue
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}
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switch val.Kind() {
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case reflect.Ptr:
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// if !val.IsValid()
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if reflect.Indirect(val).Kind() == reflect.Struct {
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infields, err := StructFields(val.Interface())
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if err != nil {
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return nil, err
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}
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for _, infield := range infields {
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infield.Path = fmt.Sprintf("%s.%s", fld.Name, infield.Path)
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fields = append(fields, infield)
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}
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} else {
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fields = append(fields, StructField{Field: fld, Value: val, Path: fld.Name})
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}
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case reflect.Struct:
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infields, err := StructFields(val.Interface())
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if err != nil {
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return nil, err
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}
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for _, infield := range infields {
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infield.Path = fmt.Sprintf("%s.%s", fld.Name, infield.Path)
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fields = append(fields, infield)
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}
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default:
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fields = append(fields, StructField{Field: fld, Value: val, Path: fld.Name})
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}
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}
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return fields, nil
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}
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// CopyDefaults for a from b
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// a and b should be pointers to the same kind of struct
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func CopyDefaults(a, b interface{}) {
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pt := reflect.TypeOf(a)
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t := pt.Elem()
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va := reflect.ValueOf(a).Elem()
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vb := reflect.ValueOf(b).Elem()
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for i := 0; i < t.NumField(); i++ {
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aField := va.Field(i)
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if aField.CanSet() {
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bField := vb.Field(i)
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aField.Set(bField)
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}
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}
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}
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// CopyFrom sets the public members of a from b
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// a and b should be pointers to structs
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// a can be a different type from b
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// Only the Fields which have the same name and assignable type on a
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// and b will be set.
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func CopyFrom(a, b interface{}) {
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ta := reflect.TypeOf(a).Elem()
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tb := reflect.TypeOf(b).Elem()
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va := reflect.ValueOf(a).Elem()
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vb := reflect.ValueOf(b).Elem()
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for i := 0; i < tb.NumField(); i++ {
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bField := vb.Field(i)
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tbField := tb.Field(i)
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name := tbField.Name
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aField := va.FieldByName(name)
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taField, found := ta.FieldByName(name)
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if found && aField.IsValid() && bField.IsValid() && aField.CanSet() && tbField.Type.AssignableTo(taField.Type) {
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aField.Set(bField)
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}
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}
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}
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// StructURLValues get struct fields via url.Values
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func StructURLValues(src interface{}, pref string, tags []string) (url.Values, error) {
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data := url.Values{}
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sv := reflect.ValueOf(src)
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if sv.Kind() == reflect.Ptr {
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sv = sv.Elem()
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}
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if sv.Kind() != reflect.Struct {
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return nil, ErrInvalidStruct
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}
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typ := sv.Type()
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for idx := 0; idx < typ.NumField(); idx++ {
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fld := typ.Field(idx)
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val := sv.Field(idx)
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if len(fld.PkgPath) != 0 || !val.IsValid() {
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continue
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}
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var t *tag
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for _, tn := range tags {
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ts, ok := fld.Tag.Lookup(tn)
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if !ok {
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continue
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}
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tp := strings.Split(ts, ",")
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// special
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switch tn {
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case "protobuf": // special
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t = &tag{key: tn, name: tp[3][5:], opts: append(tp[:3], tp[4:]...)}
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default:
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t = &tag{key: tn, name: tp[0], opts: tp[1:]}
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}
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if t.name != "" {
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break
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}
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}
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if t.name == "" {
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// fallback to lowercase
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t.name = strings.ToLower(fld.Name)
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}
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if pref != "" {
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t.name = pref + "." + t.name
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}
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if !val.IsValid() || val.IsZero() {
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continue
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}
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switch val.Kind() {
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case reflect.Struct, reflect.Ptr:
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if val.IsNil() {
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continue
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}
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ndata, err := StructURLValues(val.Interface(), t.name, tags)
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if err != nil {
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return ndata, err
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}
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for k, v := range ndata {
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data[k] = v
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}
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default:
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switch val.Kind() {
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case reflect.Slice:
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for i := 0; i < val.Len(); i++ {
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va := val.Index(i)
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// if va.Type().Elem().Kind() != reflect.Ptr {
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if va.Kind() != reflect.Ptr {
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data.Set(t.name, fmt.Sprintf("%v", va.Interface()))
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continue
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}
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switch va.Type().Elem().String() {
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case "wrapperspb.BoolValue", "wrapperspb.BytesValue", "wrapperspb.StringValue":
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if eva := reflect.Indirect(va).FieldByName("Value"); eva.IsValid() {
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data.Add(t.name, fmt.Sprintf("%v", eva.Interface()))
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}
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case "wrapperspb.DoubleValue", "wrapperspb.FloatValue":
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if eva := reflect.Indirect(va).FieldByName("Value"); eva.IsValid() {
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data.Add(t.name, fmt.Sprintf("%v", eva.Interface()))
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}
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case "wrapperspb.Int32Value", "wrapperspb.Int64Value":
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if eva := reflect.Indirect(va).FieldByName("Value"); eva.IsValid() {
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data.Add(t.name, fmt.Sprintf("%v", eva.Interface()))
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}
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case "wrapperspb.UInt32Value", "wrapperspb.UInt64Value":
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if eva := reflect.Indirect(va).FieldByName("Value"); eva.IsValid() {
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data.Add(t.name, fmt.Sprintf("%v", eva.Interface()))
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}
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default:
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data.Add(t.name, fmt.Sprintf("%v", val.Index(i).Interface()))
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}
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}
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default:
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data.Set(t.name, fmt.Sprintf("%v", val.Interface()))
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}
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}
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}
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return data, nil
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}
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// URLMap returns map of url query params
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func URLMap(query string) (map[string]interface{}, error) {
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var mp interface{} = make(map[string]interface{})
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params := strings.Split(query, "&")
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for _, part := range params {
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tm, err := queryToMap(part)
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if err != nil {
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return nil, err
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}
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mp = merge(mp, tm)
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}
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return mp.(map[string]interface{}), nil
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}
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// FlattenMap expand key.subkey to nested map
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func FlattenMap(a map[string]interface{}) map[string]interface{} {
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// preprocess map
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nb := make(map[string]interface{}, len(a))
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for k, v := range a {
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ps := strings.Split(k, ".")
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if len(ps) == 1 {
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nb[k] = v
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continue
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}
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em := make(map[string]interface{})
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em[ps[len(ps)-1]] = v
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for i := len(ps) - 2; i > 0; i-- {
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nm := make(map[string]interface{})
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nm[ps[i]] = em
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em = nm
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}
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if vm, ok := nb[ps[0]]; ok {
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// nested map
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nm := vm.(map[string]interface{})
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for vk, vv := range em {
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nm[vk] = vv
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}
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nb[ps[0]] = nm
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} else {
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nb[ps[0]] = em
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}
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}
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return nb
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}
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/*
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case reflect.String:
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fn := func(c rune) bool { return c == ',' || c == ';' || c == ' ' }
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slice := strings.FieldsFunc(vb.String(), fn)
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if va.IsNil() {
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va.Set(reflect.MakeSlice(va.Type(), len(slice), len(slice)))
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}
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*/
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func btSplitter(str string) []string {
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r := bracketSplitter.Split(str, -1)
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for idx, s := range r {
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if len(s) == 0 {
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if len(r) > idx+1 {
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copy(r[idx:], r[idx+1:])
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r = r[:len(r)-1]
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}
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}
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}
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return r
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}
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// queryToMap turns something like a[b][c]=4 into
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// map[string]interface{}{
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// "a": map[string]interface{}{
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// "b": map[string]interface{}{
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// "c": 4,
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// },
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// },
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// }
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func queryToMap(param string) (map[string]interface{}, error) {
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rawKey, rawValue, err := splitKeyAndValue(param)
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if err != nil {
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return nil, err
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}
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rawValue, err = url.QueryUnescape(rawValue)
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if err != nil {
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return nil, err
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}
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rawKey, err = url.QueryUnescape(rawKey)
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if err != nil {
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return nil, err
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}
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pieces := btSplitter(rawKey)
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key := pieces[0]
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// If len==1 then rawKey has no [] chars and we can just
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// decode this as key=value into {key: value}
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if len(pieces) == 1 {
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return map[string]interface{}{
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key: rawValue,
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}, nil
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}
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// If len > 1 then we have something like a[b][c]=2
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// so we need to turn this into {"a": {"b": {"c": 2}}}
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// To do this we break our key into two pieces:
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// a and b[c]
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// and then we set {"a": queryToMap("b[c]", value)}
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ret := make(map[string]interface{})
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ret[key], err = queryToMap(buildNewKey(rawKey) + "=" + rawValue)
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if err != nil {
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return nil, err
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}
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// When URL params have a set of empty brackets (eg a[]=1)
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// it is assumed to be an array. This will get us the
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// correct value for the array item and return it as an
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// []interface{} so that it can be merged properly.
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if pieces[1] == "" {
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temp := ret[key].(map[string]interface{})
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ret[key] = []interface{}{temp[""]}
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}
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return ret, nil
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}
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// buildNewKey will take something like:
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// origKey = "bar[one][two]"
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// pieces = [bar one two ]
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// and return "one[two]"
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func buildNewKey(origKey string) string {
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pieces := btSplitter(origKey)
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|
|
|
ret := origKey[len(pieces[0])+1:]
|
|
ret = ret[:len(pieces[1])] + ret[len(pieces[1])+1:]
|
|
return ret
|
|
}
|
|
|
|
// splitKeyAndValue splits a URL param at the last equal
|
|
// sign and returns the two strings. If no equal sign is
|
|
// found, the ErrInvalidParam error is returned.
|
|
func splitKeyAndValue(param string) (string, string, error) {
|
|
li := strings.LastIndex(param, "=")
|
|
if li == -1 {
|
|
return "", "", ErrInvalidParam
|
|
}
|
|
return param[:li], param[li+1:], nil
|
|
}
|
|
|
|
// merge merges a with b if they are either both slices
|
|
// or map[string]interface{} types. Otherwise it returns b.
|
|
func merge(a interface{}, b interface{}) interface{} {
|
|
if av, aok := a.(map[string]interface{}); aok {
|
|
if bv, bok := b.(map[string]interface{}); bok {
|
|
return mergeMapIface(av, bv)
|
|
}
|
|
}
|
|
if av, aok := a.([]interface{}); aok {
|
|
if bv, bok := b.([]interface{}); bok {
|
|
return mergeSliceIface(av, bv)
|
|
}
|
|
}
|
|
|
|
va := reflect.ValueOf(a)
|
|
vb := reflect.ValueOf(b)
|
|
if (va.Type().Kind() == reflect.Slice) && (va.Type().Elem().Kind() == vb.Type().Kind() || vb.Type().ConvertibleTo(va.Type().Elem())) {
|
|
va = reflect.Append(va, vb.Convert(va.Type().Elem()))
|
|
return va.Interface()
|
|
}
|
|
|
|
return b
|
|
}
|
|
|
|
// mergeMap merges a with b, attempting to merge any nested
|
|
// values in nested maps but eventually overwriting anything
|
|
// in a that can't be merged with whatever is in b.
|
|
func mergeMapIface(a map[string]interface{}, b map[string]interface{}) map[string]interface{} {
|
|
for bK, bV := range b {
|
|
if aV, ok := a[bK]; ok {
|
|
if (reflect.ValueOf(aV).Type().Kind() == reflect.ValueOf(bV).Type().Kind()) ||
|
|
((reflect.ValueOf(aV).Type().Kind() == reflect.Slice) && reflect.ValueOf(aV).Type().Elem().Kind() == reflect.ValueOf(bV).Type().Kind()) {
|
|
nV := []interface{}{aV, bV}
|
|
a[bK] = nV
|
|
} else {
|
|
a[bK] = merge(a[bK], bV)
|
|
}
|
|
} else {
|
|
a[bK] = bV
|
|
}
|
|
}
|
|
return a
|
|
}
|
|
|
|
// mergeSlice merges a with b and returns the result.
|
|
func mergeSliceIface(a []interface{}, b []interface{}) []interface{} {
|
|
a = append(a, b...)
|
|
return a
|
|
}
|
|
|
|
type tag struct {
|
|
key string
|
|
name string
|
|
opts []string
|
|
}
|