从嵌入式结构访问结构字段

Question

i am new in golang, i am coming from php.

i want to define a method on a struct for validating http request. but i have some problems about accessing struct fields.

there is my code.

package main

import "log"

type ReqAbstract struct{}

func (r *ReqAbstract) Validate() error {
    log.Printf("%+v", r)
    return nil
}
func (r *ReqAbstract) Validate2(req interface{}) error {
    log.Printf("%+v", req)
    return nil
}

type NewPostReq struct {
    ReqAbstract
    Title string
}

func main() {
    request := &NewPostReq{Title: "Example Title"}

    request.Validate()
    request.Validate2(request)
}

when i run this code, then i getting below result

2015/07/21 13:59:50 &{}
2015/07/21 13:59:50 &{ReqAbstract:{} Title:Example Title}

is there any way to access struct fields on Validate() method like Validate2() method ?

Answer 1

You cannot access outer struct fields from inner struct. Only inner fields from the outer. What you can do is composing:

type CommonThing struct {
    A int
    B string
}

func (ct CommonThing) Valid() bool {
    return ct.A != 0 && ct.B != ""
}

type TheThing struct {
    CommonThing
    C float64
}

func (tt TheThing) Valid() bool {
    return tt.CommonThing.Valid() && tt.C != 0
}