Reading JSON from URL string

[hyousef (Hasan Yousef)]

I want to return the string returned from this link, and build a JSON object based on the returned data, I wrote the below code that is reading the url and getting the string correctly, but it fails in building the JSON object, and do not return anything!

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
)

type Product struct {
	ProductId   string `json:"id"`
	ProductName string `json:"description"`
}

func main() {
	url := "https://script.googleusercontent.com/macros/echo?user_content_key=WBSJPDNSN6X1FCYeXsR6TDaDval0vdvmSoMmXFhGbt5sfK0ia80Dp7kPD27GLpZbYz8vrwfDiUecI2oGMjEtgfL5o8Da25T1m5_BxDlH2jW0nuo2oDemN9CCS2h10ox_1xSncGQajx_ryfhECjZEnGb6k9xaGtOX6M1tIiG811CRpk9nXl8ZKS7UJTno1dvQXMe1kqfAj8WxsSkLor-EqzOmbnRGq-tk&lib=M0B6GXYh0EOYMkP7qr1Xy9xw8GuJxFqGH"
	resp, err := http.Get(url)
	if err != nil {
		log.Fatal(err)
	}

	defer resp.Body.Close()

	htmlData, err := ioutil.ReadAll(resp.Body) //<--- here!

	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	// print out
	fmt.Println(string(htmlData))

	var product Product
	json.Unmarshal([]byte(string(htmlData)), &product)

	fmt.Printf("ID: %s, Description: %s", product.ProductId, product.ProductName)
}

Output:

{"user":[{"ProductId":1,"ProductName":"Helmet"},{"ProductId":2,"ProductName":"Glove"},{"ProductId":3,"ProductName":"Detecttor"}]}
ID: , Description:

[hyousef (Hasan Yousef)]

I got it:
1- The unmarshal target struct must match the data,

type Data struct {
   User []Product `json:"user"`
}

2- The fields types should be matching, so ProductID should be uint
3- The json OP got in output should match the tags used

type Product struct {
    ProductId   uint `json:"ProductId"`
    ProductName string `json:"ProductName"`
}

So, a working code is:

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
)

type Data struct {
	User []Product `json:"user"`
}
type Product struct {
	ProductId   uint   `json:"ProductId"`
	ProductName string `json:"ProductName"`
}

func main() {
	url := "https://script.googleusercontent.com/macros/echo?user_content_key=WBSJPDNSN6X1FCYeXsR6TDaDval0vdvmSoMmXFhGbt5sfK0ia80Dp7kPD27GLpZbYz8vrwfDiUecI2oGMjEtgfL5o8Da25T1m5_BxDlH2jW0nuo2oDemN9CCS2h10ox_1xSncGQajx_ryfhECjZEnGb6k9xaGtOX6M1tIiG811CRpk9nXl8ZKS7UJTno1dvQXMe1kqfAj8WxsSkLor-EqzOmbnRGq-tk&lib=M0B6GXYh0EOYMkP7qr1Xy9xw8GuJxFqGH"
	resp, err := http.Get(url)
	if err != nil {
		log.Fatal(err)
	}

	defer resp.Body.Close()

	htmlData, err := ioutil.ReadAll(resp.Body) 

	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	// print out
	fmt.Println(string(htmlData))

	//var product Product
	var data Data
	json.Unmarshal([]byte(string(htmlData)), &data)

	fmt.Println(data)
	fmt.Println(data.User)
	fmt.Println(data.User[0])
	fmt.Printf("id: %v, description: %s", data.User[0].ProductId, data.User[0].ProductName)
}