[WIP] Fix Multipart Bind issue

binding.go

@@ -169,15 +169,19 @@ func bindMultipartForm(r *http.Request, injector inject.Injector, obj interface{
 
 	newObj := reflect.New(reflect.TypeOf(obj))
 	// This if check is necessary due to https://github.com/martini-contrib/csrf/issues/6
-	if r.Form == nil {
+	if r.MultipartForm == nil {
 		if err := r.ParseMultipartForm(MaxMemory); err != nil {
 			return apierrors.NewBadRequest(err.Error())
 		}
 	}
 
-	d := form.NewDecoder()
-	if err := d.Decode(newObj.Interface(), r.Form); err != nil {
-		return NewBindingError(err, obj)
+	//d := form.NewDecoder()
+	//if err := d.Decode(newObj.Interface(), r.Form); err != nil {
+	//	return NewBindingError(err, obj)
+	//}
+
+	if err := mapForm(newObj, r.MultipartForm.Value, r.MultipartForm.File); err != nil {
+		return apierrors.NewBadRequest(err.Error())
 	}
 
 	if err := check(newObj); err != nil {

form.go

@@ -0,0 +1,176 @@
+package binding
+
+import (
+	"mime/multipart"
+	"reflect"
+	"strconv"
+)
+
+// NameMapper represents a form tag name mapper.
+type NameMapper func(string) string
+
+var (
+	nameMapper = func(field string) string {
+		newstr := make([]rune, 0, len(field))
+		for i, chr := range field {
+			if isUpper := 'A' <= chr && chr <= 'Z'; isUpper {
+				if i > 0 {
+					newstr = append(newstr, '_')
+				}
+				chr -= ('A' - 'a')
+			}
+			newstr = append(newstr, chr)
+		}
+		return string(newstr)
+	}
+)
+
+// SetNameMapper sets name mapper.
+func SetNameMapper(nm NameMapper) {
+	nameMapper = nm
+}
+
+// Takes values from the form data and puts them into a struct
+func mapForm(formStruct reflect.Value, form map[string][]string,
+	formfile map[string][]*multipart.FileHeader) error {
+	var err error
+	if formStruct.Kind() == reflect.Ptr {
+		formStruct = formStruct.Elem()
+	}
+	typ := formStruct.Type()
+
+	for i := 0; i < typ.NumField(); i++ {
+		typeField := typ.Field(i)
+		structField := formStruct.Field(i)
+
+		if typeField.Type.Kind() == reflect.Ptr && typeField.Anonymous {
+			structField.Set(reflect.New(typeField.Type.Elem()))
+			if err = mapForm(structField.Elem(), form, formfile); err != nil {
+				return err
+			}
+			if reflect.DeepEqual(structField.Elem().Interface(), reflect.Zero(structField.Elem().Type()).Interface()) {
+				structField.Set(reflect.Zero(structField.Type()))
+			}
+		} else if typeField.Type.Kind() == reflect.Struct {
+			if err = mapForm(structField, form, formfile); err != nil {
+				return err
+			}
+		}
+
+		inputFieldName := parseFormName(typeField.Name, typeField.Tag.Get("form"))
+		if len(inputFieldName) == 0 || !structField.CanSet() {
+			continue
+		}
+
+		inputValue, exists := form[inputFieldName]
+		if exists {
+			numElems := len(inputValue)
+			if structField.Kind() == 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), inputFieldName); err != nil {
+						return err
+					}
+				}
+				formStruct.Field(i).Set(slice)
+			} else {
+				if err = setWithProperType(typeField.Type.Kind(), inputValue[0], structField, inputFieldName); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+
+		inputFile, exists := formfile[inputFieldName]
+		if !exists {
+			continue
+		}
+		fhType := reflect.TypeOf((*multipart.FileHeader)(nil))
+		numElems := len(inputFile)
+		if structField.Kind() == reflect.Slice && numElems > 0 && structField.Type().Elem() == fhType {
+			slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
+			for i := 0; i < numElems; i++ {
+				slice.Index(i).Set(reflect.ValueOf(inputFile[i]))
+			}
+			structField.Set(slice)
+		} else if structField.Type() == fhType {
+			structField.Set(reflect.ValueOf(inputFile[0]))
+		}
+	}
+	return nil
+}
+
+func parseFormName(raw, actual string) string {
+	if len(actual) > 0 {
+		return actual
+	}
+	return nameMapper(raw)
+}
+
+// This sets the value in a struct of an indeterminate type to the
+// matching value from the request (via Form middleware) in the
+// same type, so that not all deserialized values have to be strings.
+// Supported types are string, int, float, and bool.
+func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value, nameInTag string) error {
+	switch valueKind {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		if val == "" {
+			val = "0"
+		}
+		intVal, err := strconv.ParseInt(val, 10, 64)
+		if err != nil {
+			return err
+		} else {
+			structField.SetInt(intVal)
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		if val == "" {
+			val = "0"
+		}
+		uintVal, err := strconv.ParseUint(val, 10, 64)
+		if err != nil {
+			return err
+		} else {
+			structField.SetUint(uintVal)
+		}
+	case reflect.Bool:
+		if val == "on" {
+			structField.SetBool(true)
+			break
+		}
+
+		if val == "" {
+			val = "false"
+		}
+		boolVal, err := strconv.ParseBool(val)
+		if err != nil {
+			return err
+		} else if boolVal {
+			structField.SetBool(true)
+		}
+	case reflect.Float32:
+		if val == "" {
+			val = "0.0"
+		}
+		floatVal, err := strconv.ParseFloat(val, 32)
+		if err != nil {
+			return err
+		} else {
+			structField.SetFloat(floatVal)
+		}
+	case reflect.Float64:
+		if val == "" {
+			val = "0.0"
+		}
+		floatVal, err := strconv.ParseFloat(val, 64)
+		if err != nil {
+			return err
+		} else {
+			structField.SetFloat(floatVal)
+		}
+	case reflect.String:
+		structField.SetString(val)
+	}
+	return nil
+}