在Golang中将值从一个结构复制到另一个

Question

I've two structs:

type UpdateableUser struct {
    FirstName string
    LastName string
    Email string
    Tlm float64
    Dob time.Time
}

type User struct {
    Id string
    FirstName string
    LastName string
    Email string
    DOB time.Time
    Tlm float64
    created time.Time
    updated time.Time
}

Through a binder I bind request data to the updateableUser struct, therefore I might have an updateableUser with only one "real" value, like uu here:

uu := UpdateableUser{Lastname: "Smith"}

Now I want to set only the not "emtpy" values from UpdateableUser to User. Can you please give me a hint or more?

Answer 1

I would recommend embedding the Updateable struct into the larger struct:

type UpdateableUser struct {
    FirstName string
    LastName  string
    Email     string
    Tlm       float64
    Dob       time.Time
}

type User struct {
    UpdateableUser
    ID      string
    created time.Time
   updated time.Time
}

func (u *User) UpdateFrom(src *UpdateableUser) {
    if src.FirstName != "" {
        u.FirstName = src.FirstName
    }
    if src.LastName != "" {
        u.LastName = src.LastName
    }
    // ... And other properties. Tedious, but simple and avoids Reflection
}

This allows you to use UpdateableUser as an interface to make it explicit which properties can be updated.