Function bindData

bind.go:208–359

bindData will bind data ONLY fields in destination struct that have EXPLICIT tag

(destination any, data map[string][]string, tag string, dataFiles map[string][]*multipart.FileHeader)

// bindData will bind data ONLY fields in destination struct that have EXPLICIT tag
func bindData(destination any, data map[string][]string, tag string, dataFiles map[string][]*multipart.FileHeader) error {
	if destination == nil || (len(data) == 0 && len(dataFiles) == 0) {
		return nil
	}
	hasFiles := len(dataFiles) > 0
	typ := reflect.TypeOf(destination).Elem()
	val := reflect.ValueOf(destination).Elem()

	// Support binding to limited Map destinations:
	// - map[string][]string,
	// - map[string]string <-- (binds first value from data slice)
	// - map[string]any
	// You are better off binding to struct but there are user who want this map feature. Source of data for these cases are:
	// params,query,header,form as these sources produce string values, most of the time slice of strings, actually.
	if typ.Kind() == reflect.Map && typ.Key().Kind() == reflect.String {
		k := typ.Elem().Kind()
		isElemInterface := k == reflect.Interface
		isElemString := k == reflect.String
		isElemSliceOfStrings := k == reflect.Slice && typ.Elem().Elem().Kind() == reflect.String
		if !isElemSliceOfStrings && !isElemString && !isElemInterface {
			return nil
		}
		if val.IsNil() {
			val.Set(reflect.MakeMap(typ))
		}
		for k, v := range data {
			if isElemString {
				val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v[0]))
			} else if isElemInterface {
				// To maintain backward compatibility, we always bind to the first string value
				// and not the slice of strings when dealing with map[string]any{}
				val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v[0]))
			} else {
				val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v))
			}
		}
		return nil
	}

	// !struct
	if typ.Kind() != reflect.Struct {
		if tag == "param" || tag == "query" || tag == "header" {
			// incompatible type, data is probably to be found in the body
			return nil
		}
		return errors.New("binding element must be a struct")
	}

	meta := bindMetaFor(typ)
	for fi := range meta.fields { // iterate over all destination fields
		fm := &meta.fields[fi]
		structField := val.Field(fm.index)
		if fm.anonymous {
			if structField.Kind() == reflect.Pointer {
				structField = structField.Elem()
			}
		}
		if !structField.CanSet() {