gin/binding/binding.go

92 lines
1.8 KiB
Go

package binding
import (
"encoding/json"
"encoding/xml"
"errors"
"net/http"
"reflect"
"strings"
)
type (
Binding interface {
Bind(*http.Request, interface{}) error
}
// JSON binding
jsonBinding struct{}
// XML binding
xmlBinding struct{}
// // form binding
formBinding struct{}
)
var (
JSON = jsonBinding{}
XML = xmlBinding{}
Form = formBinding{} // todo
)
func (_ jsonBinding) Bind(req *http.Request, obj interface{}) error {
decoder := json.NewDecoder(req.Body)
if err := decoder.Decode(obj); err == nil {
return Validate(obj)
} else {
return err
}
}
func (_ xmlBinding) Bind(req *http.Request, obj interface{}) error {
decoder := xml.NewDecoder(req.Body)
if err := decoder.Decode(obj); err == nil {
return Validate(obj)
} else {
return err
}
}
func (_ formBinding) Bind(req *http.Request, obj interface{}) error {
return nil
}
func Validate(obj interface{}) error {
typ := reflect.TypeOf(obj)
val := reflect.ValueOf(obj)
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
val = val.Elem()
}
for i := 0; i < typ.NumField(); i++ {
field := typ.Field(i)
fieldValue := val.Field(i).Interface()
zero := reflect.Zero(field.Type).Interface()
// Validate nested and embedded structs (if pointer, only do so if not nil)
if field.Type.Kind() == reflect.Struct ||
(field.Type.Kind() == reflect.Ptr && !reflect.DeepEqual(zero, fieldValue)) {
if err := Validate(fieldValue); err != nil {
return err
}
}
if strings.Index(field.Tag.Get("binding"), "required") > -1 {
if reflect.DeepEqual(zero, fieldValue) {
name := field.Name
if j := field.Tag.Get("json"); j != "" {
name = j
} else if f := field.Tag.Get("form"); f != "" {
name = f
}
return errors.New("Required " + name)
}
}
}
return nil
}