GJSON example of ForEach()

gjson_foreach_example.go

package main

import "github.com/tidwall/gjson"
import "fmt"
import "strings"

func main() {
    jsonstring := `
{
    "status":"ok",
    "data":{
        "aqi":21,
        "idx":1451,
        "attributions":[
            {
                "url":"http://www.bjmemc.com.cn/",
                "name":"Beijing Environmental Protection Monitoring Center (北京市环境保护监测中心)"
            },
            {
                "url":"https://china.usembassy-china.org.cn/embassy-consulates/beijing/air-quality-monitor/",
                "name":"U.S Embassy Beijing Air Quality Monitor (美国驻北京大使馆空气质量监测)"
            },
            {
                "url":"https://waqi.info/",
                "name":"World Air Quality Index Project"
            }
        ],
        "city":{
            "geo":[
                39.954592,
                116.468117
            ],
            "name":"Beijing (北京)",
            "url":"https://aqicn.org/city/beijing"
        },
        "dominentpol":"pm25",
        "iaqi":{
            "co":{
                "v":2.8
            },
            "no2":{
                "v":5.1
            },
            "o3":{
                "v":26
            },
            "pm10":{
                "v":15
            },
            "pm25":{
                "v":21
            },
            "so2":{
                "v":0.6
            },
            "w":{
                "v":7.7
            }
        },
        "time":{
            "s":"2019-12-10 15:00:00",
            "tz":"+08:00",
            "v":1575990000
        },
        "debug":{
            "sync":"2019-12-10T16:29:00+09:00"
        }
    }
}
`
    parsedJson := gjson.Parse(jsonstring)
    parsedJson.ForEach(jsoniter)
}

var stack []string

func jsoniter(key, v gjson.Result) bool {
    keypath := fmt.Sprintf("%s", key)
    if keypath == "" {
        keypath = "[]"
    }
    stack = append(stack, keypath)
    keypath = strings.Join(stack[:], ".")

    switch v.Type {
    case gjson.JSON:
        v.ForEach(jsoniter)
        fmt.Printf("%30s    %10s\n", keypath, v.Type)
    case gjson.String:
        fmt.Printf("%30s    %10s    %s\n", keypath, v.Type, v.String())
    case gjson.Number:
        fmt.Printf("%30s    %10s    %s\n", keypath, v.Type, v.String())
    case gjson.True:
        fmt.Printf("%30s    %10s    %s\n", keypath, v.Type, v.String())
    case gjson.False:
        fmt.Printf("%30s    %10s    %s\n", keypath, v.Type, v.String())
    case gjson.Null:
        fmt.Printf("%30s    %10s    %s\n", keypath, v.Type, v.String())
    default:
        panic("error")
    }
    stack = stack[:len(stack) - 1]
    return true
}

output

[rj]$ go run ./gjson_foreach.go 
                        status        String    ok
                      data.aqi        Number    21
                      data.idx        Number    1451
      data.attributions.[].url        String    http://www.bjmemc.com.cn/
     data.attributions.[].name        String    Beijing Environmental Protection Monitoring Center (北京市环境保护监测中心)
          data.attributions.[]          JSON
      data.attributions.[].url        String    https://china.usembassy-china.org.cn/embassy-consulates/beijing/air-quality-monitor/
     data.attributions.[].name        String    U.S Embassy Beijing Air Quality Monitor (美国驻北京大使馆空气质量监测)
          data.attributions.[]          JSON
      data.attributions.[].url        String    https://waqi.info/
     data.attributions.[].name        String    World Air Quality Index Project
          data.attributions.[]          JSON
             data.attributions          JSON
              data.city.geo.[]        Number    39.954592
              data.city.geo.[]        Number    116.468117
                 data.city.geo          JSON
                data.city.name        String    Beijing (北京)
                 data.city.url        String    https://aqicn.org/city/beijing
                     data.city          JSON
              data.dominentpol        String    pm25
                data.iaqi.co.v        Number    2.8
                  data.iaqi.co          JSON
               data.iaqi.no2.v        Number    5.1
                 data.iaqi.no2          JSON
                data.iaqi.o3.v        Number    26
                  data.iaqi.o3          JSON
              data.iaqi.pm10.v        Number    15
                data.iaqi.pm10          JSON
              data.iaqi.pm25.v        Number    21
                data.iaqi.pm25          JSON
               data.iaqi.so2.v        Number    0.6
                 data.iaqi.so2          JSON
                 data.iaqi.w.v        Number    7.7
                   data.iaqi.w          JSON
                     data.iaqi          JSON
                   data.time.s        String    2019-12-10 15:00:00
                  data.time.tz        String    +08:00
                   data.time.v        Number    1575990000
                     data.time          JSON
               data.debug.sync        String    2019-12-10T16:29:00+09:00
                    data.debug          JSON
                          data          JSON