reflect_load_value_to_struct.go

package main

import (
	"fmt"
	"reflect"
	"strings"
)

func loadValue(i interface{}, m map[string]string) {
	rconfigPtr := reflect.ValueOf(i)
	rconfig := reflect.Indirect(rconfigPtr)

	for k, v := range m {
		_, ok := rconfig.Type().FieldByName(k)
		if ok {
			field := rconfig.FieldByName(k)
			fieldType := field.Kind()
			if fieldType == reflect.Bool {
				if v == "True" {
					field.SetBool(true)
				} else if v == "False" {
					field.SetBool(false)
				} else {
					fmt.Printf("The map provided a unvalid value for field: %s, value: %s, valid values are: True/False", k, v)
				}
			} else if fieldType == reflect.String {
				field.SetString(v)
			} else if fieldType == reflect.Slice {
				if field.Type().Elem().Kind() == reflect.String {
					values := strings.Split(v, ",")
					field.Set(reflect.ValueOf(values))
				} else {
					fmt.Printf("struct using a unsupported slice type: %s, only support []string", field.Elem().Kind().String())
				}
			} else {
				fmt.Printf("struct using a unsupported type: %s, only support bool/string.", fieldType)
			}
		} else {
			fmt.Printf("The map contains a unknown key-value pair: %s:%s", k, v)
		}
	}
}

type Config struct {
	T  bool
	SL []string
}

func main() {
	c := Config{}
	fmt.Println(c)
	loadValue(&c, map[string]string{"T": "True", "SL": "v1,v2"})
	fmt.Println(c)
}