gin/binding/form_mapping.go
2017-09-28 22:23:18 +08:00

191 lines
4.6 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"
"reflect"
"strconv"
"time"
)
func mapForm(ptr interface{}, form map[string][]string) 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)
if !structField.CanSet() {
continue
}
structFieldKind := structField.Kind()
inputFieldName := typeField.Tag.Get("form")
if inputFieldName == "" {
inputFieldName = typeField.Name
// if "form" tag is nil, we inspect if the field is a struct.
// this would not make sense for JSON parsing but it does for a form
// since data is flatten
if structFieldKind == reflect.Struct {
err := mapForm(structField.Addr().Interface(), form)
if err != nil {
return err
}
continue
}
}
inputValue, exists := form[inputFieldName]
if !exists {
continue
}
numElems := len(inputValue)
if structFieldKind == reflect.Slice && numElems > 0 {
sliceOf := structField.Type().Elem().Kind()
slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
for i := 0; i < numElems; i++ {
if err := setWithProperType(sliceOf, inputValue[i], slice.Index(i)); err != nil {
return err
}
}
val.Field(i).Set(slice)
} else {
if _, isTime := structField.Interface().(time.Time); isTime {
if err := setTimeField(inputValue[0], typeField, structField); err != nil {
return err
}
continue
}
if err := setWithProperType(typeField.Type.Kind(), inputValue[0], structField); err != nil {
return err
}
}
}
return nil
}
func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value) error {
switch valueKind {
case reflect.Int:
return setIntField(val, 0, structField)
case reflect.Int8:
return setIntField(val, 8, structField)
case reflect.Int16:
return setIntField(val, 16, structField)
case reflect.Int32:
return setIntField(val, 32, structField)
case reflect.Int64:
return setIntField(val, 64, structField)
case reflect.Uint:
return setUintField(val, 0, structField)
case reflect.Uint8:
return setUintField(val, 8, structField)
case reflect.Uint16:
return setUintField(val, 16, structField)
case reflect.Uint32:
return setUintField(val, 32, structField)
case reflect.Uint64:
return setUintField(val, 64, structField)
case reflect.Bool:
return setBoolField(val, structField)
case reflect.Float32:
return setFloatField(val, 32, structField)
case reflect.Float64:
return setFloatField(val, 64, structField)
case reflect.String:
structField.SetString(val)
default:
return errors.New("Unknown type")
}
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 nil
}
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 == "" {
return errors.New("Blank time format")
}
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
}
// Don't pass in pointers to bind to. Can lead to bugs. See:
// https://github.com/codegangsta/martini-contrib/issues/40
// https://github.com/codegangsta/martini-contrib/pull/34#issuecomment-29683659
func ensureNotPointer(obj interface{}) {
if reflect.TypeOf(obj).Kind() == reflect.Ptr {
panic("Pointers are not accepted as binding models")
}
}