How to unmarshal xml data from online xml file

I have an xml file on suppose https://www.notre-shop.com/sitemap_products_1.xml and I want to unmarshal this xml in my go code so I did this

package main

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

var Product struct {
    Locs []string `xml:"url>loc"`
    Name []string `xml:"url>image:title"`
}

func main() {
    res, err := http.Get("https://www.notre-shop.com/sitemap_products_1.xml")
    if err!=nil{
        log.Fatal(err)
    }

    data, err := ioutil.ReadAll(res.Body)
    if err!=nil{
        log.Fatal(err)
    }
    defer res.Body.Close()

    err = xml.Unmarshal(data, &Product)
    if err!=nil{
        log.Fatal(err)
    }
    for x, _ := range Product.Name {
        fmt.Println(Product.Name[x], Product.Locs[x])
    }
}

But this doesn't print anything. What am I doing wrong?

Here is the complete code https://play.golang.org/p/pZ6j4-lSEz on play.

Please try the following code which works for me (note: you could also use ioutil.ReadAll and xml.Unmarshal as you had before, instead of xml.Decode):

package main

import (
	"encoding/xml"
	"fmt"
	"log"
	"net/http"
)

// <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:image="http://www.google.com/schemas/sitemap-image/1.1">
//    <url>
//        <loc>
//            https://www.notre-shop.com/products/test-product-releasing-soon-2
//        </loc>
//        <lastmod>2017-01-17T08:04:44Z</lastmod>
//        <changefreq>daily</changefreq>
//        <image:image>
//            <image:loc>
//                https://cdn.shopify.com/s/files/1/0624/0605/products/NOTRE-CHICAGO-QK9C9548_fde37b05-495e-47b0-8dd1-b053c9ed3545.jpg?v=1481853712
//            </image:loc>
//            <image:title>Test Product Releasing Soon 2</image:title>
//        </image:image>
//    </url>
// </urlset>
type URLSet struct {
	XMLName string `xml:"urlset"`

	URLs []URL `xml:"url"`
}

type URL struct {
	Loc   string `xml:"loc"`
	Image Image  `xml:"image"`
}

type Image struct {
	Title string `xml:"title"`
}

func main() {
	resp, err := http.Get("https://www.notre-shop.com/sitemap_products_1.xml")
	if err != nil {
		log.Fatalln(err) // log.Fatal always exits the program, need to check err != nil first
	}
	defer resp.Body.Close()

	var urlSet URLSet
	if err = xml.NewDecoder(resp.Body).Decode(&urlSet); err != nil {
		log.Fatalln(err)
	}

	for _, url := range urlSet.URLs {
		fmt.Println(url.Loc, url.Image.Title)
	}
}

This is what the XML Specification says

> The Namespaces in XML Recommendation [XML Names] assigns a meaning
> to names containing colon characters. Therefore, authors should not
> use the colon in XML names except for namespace purposes, but XML
> processors must accept the colon as a name character.

This is the XML Namespace Recommendation says

> The XML Namespaces Recommendation expresses universal names in an
> indirect way that is compatible with XML 1.0. In effect the XML
> Namespaces Recommendation defines a mapping from an XML 1.0 tree where
> element type names and attribute names are local names into a tree
> where element type names and attribute names can be universal names.
> The mapping is based on the idea of a prefix. If an element type name
> or attribute name contains a colon, then the mapping treats the part
> of the name before the colon as a prefix, and the part of the name
> after the colon as the local name. A prefix foo refers to the URI
> specified in the value of the xmlns:foo attribute.

You may not use name with colon(:) to get the inner elements rather you can avoid the pefix ,here is your code re-written

And for performance/memory considerations since you are getting a io.Reader you may use xml.Decoder instead of xml.Unmarshal.

package main

import (
	"encoding/xml"
	"fmt"
	"log"
	"net/http"
)

var Product struct {
	Locs []string `xml:"url>loc"`
	Name []Image  `xml:"url>image"`
}

type Image struct {
	Title string `xml:"title"`
}

func main() {
	res, err := http.Get("https://www.notre-shop.com/sitemap_products_1.xml")
	if err != nil {
		log.Fatal(err)
	}
	defer res.Body.Close()
	decoder := xml.NewDecoder(res.Body)
	err = decoder.Decode(&Product)
	if err != nil {
		log.Fatal(err)
	}
	for x, _ := range Product.Name {
		fmt.Println(Product.Name[x].Title, Product.Locs[x])
	}
}

Here is play link play