Traverse a nested object by yaml/json tags

main.go

package main

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

type Monitor struct {
	Id         int       `json:"id"`
	Name       string    `json:"name"`
	Thresholds Threshold `json:"thresholds,omitempty"`
	TestBool   bool      `json:"testBool,omitempty"`
}

type Threshold struct {
	Critical int `json:"critical"`
	Warning  int `json:"warning"`
}

func setProperty(name string, obj interface{}, val interface{}) {
	parts := strings.Split(name,".")

	parent := reflect.ValueOf(obj)
	for i, field := range parts {
		current := getReflectedField(field,parent)
		if i == len(parts)-1{
			// reached the final object - set the value
			v := reflect.Indirect(current)
			switch v.Kind() {
			case reflect.Int:
				num, ok := val.(int)
				if ok {
					v.SetInt(int64(num))
				}
			case reflect.String:
				str, ok := val.(string)
				if ok {
					v.SetString(str)
				}
			case reflect.Bool:
				b, ok := val.(bool)
				if ok {
					v.SetBool(b)
				}
			}
		} else {
			parent = current
		}
	}
}

func getReflectedField(name string, v reflect.Value) reflect.Value {
	r := v.Elem()

	for i := 0; i < r.NumField(); i++ {
		fName := r.Type().Field(i).Name
        tags := r.Type().Field(i).Tag
        if matches(fName,name,string(tags)) {
			// it's the field we want
			v = reflect.Indirect(v)
			return v.Field(i).Addr()
        }
	}
	return reflect.Value{}
}

// returns true if fieldName either matches the name of the field of the json/yaml tags match
func matches(fieldName string, desiredName string, tags string) bool {
	if strings.ToLower(fieldName) == strings.ToLower(desiredName) {
		return true
	}
	
	// check json/yaml field name
	var re = regexp.MustCompile(`(?m)(json|yaml):\"[a-zA-Z]+(,.+|\")`)
	return re.MatchString(desiredName)
}


func main() {
	monitor := Monitor{
		Id:   3,
		Name: "TestMonitor",
		Thresholds: Threshold{
			Warning:  2,
			Critical: 4,
		},
		TestBool: false,
	}

	mynum := 500
	setProperty("thresholds.critical",&monitor,mynum)
	setProperty("name",&monitor,"IHateReflection")
	fmt.Printf("%+v\n",monitor)
}