Using PUT to update several JSON data in one request - json

Question

I followed this guide Developing a simple CRUD API with Go, Gin and Gorm to build my first RESTful service in golang, I can read parameter(s) from my web service, and update one value of parameter, But how to parse the JSON to update several values of parameters at one PUT request.
The CURL command I intend to use for my test as bellow
$ curl -i -X PUT http://localhost:8080/params -d '{ [ {"id":"1","value": "10"}, {"id":"2","value": "20"}] }'
Following is my code
package main
import (
"fmt"
"log"
"github.com/gin-contrib/cors"
"github.com/gin-gonic/gin"
"github.com/jinzhu/gorm"
_ "github.com/go-sql-driver/mysql"
)
type Param struct {
ID int `json:"id" `
Name string `json:"name"`
Title string `json:"title"`
Value string `json:"value"`
}
type ParamValue struct {
ID int `json:"id" `
// Name string `json:"name"`
// Title string `json:"title"`
Value string `json:"value"`
}
var db *gorm.DB
var err error
func main() {
db, err = gorm.Open("mysql", "user:password#tcp(127.0.0.1:3306)/test?charset=utf8&parseTime=True&loc=Local")
defer db.Close()
if err != nil {
log.Panic(err.Error())
}
db.AutoMigrate(&Param{})
r := gin.Default()
r.GET("/params", GetParams)
r.GET("/params/:id", GetParam)
r.PUT("/params/:id", UpdateParam)
r.PUT("/params", UpdateParams) // How to implement this one
r.Use(cors.Default())
r.Run()
}
func GetParams(c *gin.Context) {
var params []Param
if err := db.Find(&params).Error; err != nil {
c.AbortWithStatus(404)
} else {
c.JSON(200, params)
}
}
func GetParam(c *gin.Context) {
id := c.Params.ByName("id")
var param Param
if err := db.Where("id = ?", id).First(&param).Error; err != nil {
c.AbortWithStatus(404)
} else {
c.JSON(200, param)
}
}
func UpdateParams(c *gin.Context) {
// Debug info
fmt.Println("c.Request.Method >> " + c.Request.Method)
fmt.Println("c.Request.URL.String() >> " + c.Request.URL.String())
// command for testing
// $ curl -i -X PUT http://localhost:8080/params -d '{ [ {"id":"1","value": "10"}, {"id":"2","value": "20"}] }'
}
func UpdateParam(c *gin.Context) {
var param Param
id := c.Params.ByName("id")
if err := db.Where("id = ?", id).First(&param).Error; err != nil {
c.AbortWithStatus(404)
} else {
name := param.Name // readonly
c.BindJSON(&param)
if param.Name != name { // if changed
param.Name = name // restore the origin
}
db.Save(&param)
c.JSON(200, param)
}
// $ curl -i -X PUT http://localhost:8080/params/63 -d '{ "name": "recharge", "title": "switch 0/1:on/off", "value": "1"}'
}
Any help is appreciated.

Answer 1

first of all, you json is invalid.
I guess that this is what you wanted:
[{"id":"1" ,"value": "10"}, {"id":"2" ,"value": "20"}]
an easier solution will be to add an struct that match your json:
and then add the json.Unmarshal to parse the json:
jsn := `[{"id":"1" ,"value": "10"}, {"id":"2" ,"value": "20"}]`
var data yourSturctName
json.Unmarshal([]byte(jsn), &data)
for _, r := range data {
fmt.Printf("ID:%s Value:%s", r.ID, r.Value)
}
then add that into your logic.