在Go中创建从API读取的结构

Question

I'm working on a project and it is my first time using Go.

The project queries a number of APIs and for the most part I have had no trouble getting this working.

Coming from a PHP background, creating Go type definitions for my JSON responses is a little different.

I am stuck on one API, a Magento API, that returns a JSON response like so:

{
    "66937": {
        "entity_id": "66937",
        "website_id": "1",
        "email": "[e-mail]",
        "group_id": "1",
        "created_at": "2017-08-11 02:09:18",
        "disable_auto_group_change": "0",
        "firstname": "Joe",
        "lastname": "Bloggs",
        "created_in": "New Zealand Store View"
    },
    "66938": {
        "entity_id": "66938",
        "website_id": "1",
        "email": "[e-mail]",
        "group_id": "1",
        "created_at": "2017-08-11 02:16:41",
        "disable_auto_group_change": "0",
        "firstname": "Jane",
        "lastname": "Doe",
        "created_in": "New Zealand Store View"
    }
}

I have been using a tool, JSON-to-Go, to help me create the struct types, however it doesn't look quite right for this style of response:

type AutoGenerated struct {
    Num0 struct {
        EntityID               string `json:"entity_id"`
        WebsiteID              string `json:"website_id"`
        Email                  string `json:"email"`
        GroupID                string `json:"group_id"`
        CreatedAt              string `json:"created_at"`
        DisableAutoGroupChange string `json:"disable_auto_group_change"`
        Firstname              string `json:"firstname"`
        Lastname               string `json:"lastname"`
        CreatedIn              string `json:"created_in"`
    } `json:"0"`
    Num1 struct {
        EntityID               string `json:"entity_id"`
        WebsiteID              string `json:"website_id"`
        Email                  string `json:"email"`
        GroupID                string `json:"group_id"`
        CreatedAt              string `json:"created_at"`
        DisableAutoGroupChange string `json:"disable_auto_group_change"`
        Firstname              string `json:"firstname"`
        Lastname               string `json:"lastname"`
        CreatedIn              string `json:"created_in"`
    } `json:"1"`
}

All I am interested in is the inner JSON - the stuff to actually do with the customer. I am looping over this to extract some information.

How do I create the required struct to read from this?

I have looked at any number of documents or articles but they tend to use more simple JSON responses as examples.

Answer 1

For your JSON structure following might suit well.

Play Link: https://play.golang.org/p/ygXsdYALCb

Create a struct called Info or name you prefer also customize your field names as you like.

type Info struct {
    EntityID               string `json:"entity_id"`
    WebsiteID              string `json:"website_id"`
    Email                  string `json:"email"`
    GroupID                string `json:"group_id"`
    CreatedAt              string `json:"created_at"`
    DisableAutoGroupChange string `json:"disable_auto_group_change"`
    Firstname              string `json:"firstname"`
    Lastname               string `json:"lastname"`
    CreatedIn              string `json:"created_in"`
}

And create map of Info struct and the unmarshal it.

var result map[string]Info
if err := json.Unmarshal(jsonBytes, &result); err != nil {
    fmt.Println(err)
}
fmt.Printf("%+v", result)

---

EDIT:

As asked in the comment, adding for example:

fmt.Println("Accessing unmarshal values:")
for key, info := range result {
    fmt.Println("Key:", key)
    fmt.Printf("Complete Object: %+v
", info)
    fmt.Println("Individual value, typical object field access:")
    fmt.Println("EntityID:", info.EntityID)
    fmt.Println("Email:", info.Email)
}