如何从字符串表示形式的变量中获取嵌套结构？

Question

I have a JSON file looks like following somehow

{
    "type": "Weekly",
    "clients": [
        "gozo",
        "dva"
    ],
    "sender": "[e-mail]",
    "recipients": {
        "gozo": [
            "[e-mail]",
            "[e-mail]"
        ],
        "dva": [
            "[e-mail]",
            "[e-mail]"
        ]
    },
    "features": [
        "Top5UsedApps",
        "TimeSpentOnEachL3",
        "NewlyAssignedL3",
        "HoursLogged"
    ],
    "dbCloning": [
        "dva"
    ] 
}

I have mapped structs like the following.

type receivers struct {
    Gozo []string `json:"gozo"`
    Dva  []string `json:"dva"`
    // Add more recievers
}

// Config -- The config object parsed from the JSON file
type Config struct {
    ReportType string    `json:"type"`
    Clients    []string  `json:"clients"`
    Sender     string    `json:"sender"`
    Recipients receivers `json:"recipients"`
    Cloning    []string  `json:"dbCloning"`
}

Then somewhere in the another source file, I do the following,

func main() {
    conf := LoadConfig(os.Args[1])
    for _, client := range conf.Clients {

        // Use the client variable of some other function calls

        fmt.Println(conf.Recipients[client]) // This will not work
}

Now my question is how can I make it work. I can not loop over conf.Recipients directly.

PS: Consider that LoadConfig function unmarshal the JSON and returns a conf object.

Edit 1: It looks like it was design decision error. Now going with the solution of map[string][]string. But not marking it as an answer because the need to know how it is easily done for all the cases where there was no other choices.

Answer 1

The problem is that your type receivers shouldn't have named fields. It should be a map[string][]string instead.

Here is a working example:

package main

import (
    "encoding/json"
    "fmt"
)

type Config struct {
    ReportType string              `json:"type"`
    Clients    []string            `json:"clients"`
    Sender     string              `json:"sender"`
    Recipients map[string][]string `json:"recipients"`
    Cloning    []string            `json:"dbCloning"`
}

var data = []byte(`{
    "type": "Weekly",
    "clients": [
        "gozo",
        "dva"
    ],
    "sender": "[e-mail]",
    "recipients": {
        "gozo": [
            "[e-mail]",
            "[e-mail]"
        ],
        "dva": [
            "[e-mail]",
            "[e-mail]"
        ]
    },
    "features": [
        "Top5UsedApps",
        "TimeSpentOnEachL3",
        "NewlyAssignedL3",
        "HoursLogged"
    ],
    "dbCloning": [
        "dva"
    ] 
}`)

func main() {
    var conf Config
    json.Unmarshal(data, &conf)

    for _, client := range conf.Clients {
        fmt.Println(conf.Recipients[client])
    }
}

Gives the output

[[e-mail] [e-mail]]
[[e-mail] [e-mail]]