gin/binding/form_mapping.go
Boyi Wu c16bfa7949 update for supporting file binding (#1264)
update for supporting multipart form and file binding 

example:
```
type PhoptUploadForm struct {
	imgData    *multipart.FileHeader `form:"img_data" binding:"required"`
	ProjectID   string `form:"project_id" binding:"required"`
	Description string `form:"description binding:"required"`
}
```


ref: https://github.com/gin-gonic/gin/issues/1263
2019-03-18 10:16:34 +08:00

333 lines
7.1 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"
"fmt"
"net/http"
"reflect"
"strconv"
"strings"
"time"
"github.com/gin-gonic/gin/internal/json"
)
func mapFiles(ptr interface{}, req *http.Request) error {
typ := reflect.TypeOf(ptr).Elem()
val := reflect.ValueOf(ptr).Elem()
for i := 0; i < typ.NumField(); i++ {
typeField := typ.Field(i)
structField := val.Field(i)
t := fmt.Sprintf("%s", typeField.Type)
if string(t) != "*multipart.FileHeader" {
continue
}
inputFieldName := typeField.Tag.Get("form")
if inputFieldName == "" {
inputFieldName = typeField.Name
}
_, fileHeader, err := req.FormFile(inputFieldName)
if err != nil {
return err
}
structField.Set(reflect.ValueOf(fileHeader))
}
return nil
}
var errUnknownType = errors.New("Unknown type")
func mapUri(ptr interface{}, m map[string][]string) error {
return mapFormByTag(ptr, m, "uri")
}
func mapForm(ptr interface{}, form map[string][]string) error {
return mapFormByTag(ptr, form, "form")
}
var emptyField = reflect.StructField{}
func mapFormByTag(ptr interface{}, form map[string][]string, tag string) error {
_, err := mapping(reflect.ValueOf(ptr), emptyField, form, tag)
return err
}
func mapping(value reflect.Value, field reflect.StructField, form map[string][]string, tag string) (bool, error) {
var vKind = value.Kind()
if vKind == reflect.Ptr {
var isNew bool
vPtr := value
if value.IsNil() {
isNew = true
vPtr = reflect.New(value.Type().Elem())
}
isSetted, err := mapping(vPtr.Elem(), field, form, tag)
if err != nil {
return false, err
}
if isNew && isSetted {
value.Set(vPtr)
}
return isSetted, nil
}
ok, err := tryToSetValue(value, field, form, tag)
if err != nil {
return false, err
}
if ok {
return true, nil
}
if vKind == reflect.Struct {
tValue := value.Type()
var isSetted bool
for i := 0; i < value.NumField(); i++ {
if !value.Field(i).CanSet() {
continue
}
ok, err := mapping(value.Field(i), tValue.Field(i), form, tag)
if err != nil {
return false, err
}
isSetted = isSetted || ok
}
return isSetted, nil
}
return false, nil
}
func tryToSetValue(value reflect.Value, field reflect.StructField, form map[string][]string, tag string) (bool, error) {
var tagValue, defaultValue string
var isDefaultExists bool
tagValue = field.Tag.Get(tag)
tagValue, opts := head(tagValue, ",")
if tagValue == "-" { // just ignoring this field
return false, nil
}
if tagValue == "" { // default value is FieldName
tagValue = field.Name
}
if tagValue == "" { // when field is "emptyField" variable
return false, nil
}
var opt string
for len(opts) > 0 {
opt, opts = head(opts, ",")
k, v := head(opt, "=")
switch k {
case "default":
isDefaultExists = true
defaultValue = v
}
}
vs, ok := form[tagValue]
if !ok && !isDefaultExists {
return false, nil
}
switch value.Kind() {
case reflect.Slice:
if !ok {
vs = []string{defaultValue}
}
return true, setSlice(vs, value, field)
case reflect.Array:
if !ok {
vs = []string{defaultValue}
}
if len(vs) != value.Len() {
return false, fmt.Errorf("%q is not valid value for %s", vs, value.Type().String())
}
return true, setArray(vs, value, field)
default:
var val string
if !ok {
val = defaultValue
}
if len(vs) > 0 {
val = vs[0]
}
return true, setWithProperType(val, value, field)
}
}
func setWithProperType(val string, value reflect.Value, field reflect.StructField) error {
switch value.Kind() {
case reflect.Int:
return setIntField(val, 0, value)
case reflect.Int8:
return setIntField(val, 8, value)
case reflect.Int16:
return setIntField(val, 16, value)
case reflect.Int32:
return setIntField(val, 32, value)
case reflect.Int64:
switch value.Interface().(type) {
case time.Duration:
return setTimeDuration(val, value, field)
}
return setIntField(val, 64, value)
case reflect.Uint:
return setUintField(val, 0, value)
case reflect.Uint8:
return setUintField(val, 8, value)
case reflect.Uint16:
return setUintField(val, 16, value)
case reflect.Uint32:
return setUintField(val, 32, value)
case reflect.Uint64:
return setUintField(val, 64, value)
case reflect.Bool:
return setBoolField(val, value)
case reflect.Float32:
return setFloatField(val, 32, value)
case reflect.Float64:
return setFloatField(val, 64, value)
case reflect.String:
value.SetString(val)
case reflect.Struct:
switch value.Interface().(type) {
case time.Time:
return setTimeField(val, field, value)
}
return json.Unmarshal([]byte(val), value.Addr().Interface())
case reflect.Map:
return json.Unmarshal([]byte(val), value.Addr().Interface())
default:
return errUnknownType
}
return nil
}
func setIntField(val string, bitSize int, field reflect.Value) error {
if val == "" {
val = "0"
}
intVal, err := strconv.ParseInt(val, 10, bitSize)
if err == nil {
field.SetInt(intVal)
}
return err
}
func setUintField(val string, bitSize int, field reflect.Value) error {
if val == "" {
val = "0"
}
uintVal, err := strconv.ParseUint(val, 10, bitSize)
if err == nil {
field.SetUint(uintVal)
}
return err
}
func setBoolField(val string, field reflect.Value) error {
if val == "" {
val = "false"
}
boolVal, err := strconv.ParseBool(val)
if err == nil {
field.SetBool(boolVal)
}
return err
}
func setFloatField(val string, bitSize int, field reflect.Value) error {
if val == "" {
val = "0.0"
}
floatVal, err := strconv.ParseFloat(val, bitSize)
if err == nil {
field.SetFloat(floatVal)
}
return err
}
func setTimeField(val string, structField reflect.StructField, value reflect.Value) error {
timeFormat := structField.Tag.Get("time_format")
if timeFormat == "" {
timeFormat = time.RFC3339
}
if val == "" {
value.Set(reflect.ValueOf(time.Time{}))
return nil
}
l := time.Local
if isUTC, _ := strconv.ParseBool(structField.Tag.Get("time_utc")); isUTC {
l = time.UTC
}
if locTag := structField.Tag.Get("time_location"); locTag != "" {
loc, err := time.LoadLocation(locTag)
if err != nil {
return err
}
l = loc
}
t, err := time.ParseInLocation(timeFormat, val, l)
if err != nil {
return err
}
value.Set(reflect.ValueOf(t))
return nil
}
func setArray(vals []string, value reflect.Value, field reflect.StructField) error {
for i, s := range vals {
err := setWithProperType(s, value.Index(i), field)
if err != nil {
return err
}
}
return nil
}
func setSlice(vals []string, value reflect.Value, field reflect.StructField) error {
slice := reflect.MakeSlice(value.Type(), len(vals), len(vals))
err := setArray(vals, slice, field)
if err != nil {
return err
}
value.Set(slice)
return nil
}
func setTimeDuration(val string, value reflect.Value, field reflect.StructField) error {
d, err := time.ParseDuration(val)
if err != nil {
return err
}
value.Set(reflect.ValueOf(d))
return nil
}
func head(str, sep string) (head string, tail string) {
idx := strings.Index(str, sep)
if idx < 0 {
return str, ""
}
return str[:idx], str[idx+len(sep):]
}