Golang : Get Alexa ranking data example

Problem :

You want to get a website Alexa ranking and process the data in Golang.

Maybe for tracking a competitor ranking or tracking a publisher ranking where you put your advertising money. How to do that with a software instead of visiting Alexa.com all the time?

Solution : For this tutorial example, we will use the old Alexa API version(before they got acquired by Amazon). The API can be accessed at :

http://data.alexa.com/data?cli=10&url=domainname

For instance, a query of socketloop.com popularity with

http://data.alexa.com/data?cli=10&url=socketloop.com

will yield the following result :

 <ALEXA VER="0.9" URL="socketloop.com/" HOME="0" AID="=" IDN="socketloop.com/">
 <SD>
 <POPULARITY URL="socketloop.com/" TEXT="291466" SOURCE="panel"/>
 <REACH RANK="237320"/>
 <RANK DELTA="+31735"/>
 <COUNTRY CODE="US" NAME="United States" RANK="191742"/>
 </SD>
 </ALEXA>

NOTE : If you wish to extract more data from Alexa.com, you will have to use the latest API. See http://docs.aws.amazon.com/AlexaWebInfoService/latest/

Here you go! The Golang code to extract popularity ranking :

 package main

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

 func main() {

 domainName := "socketloop.com"

 resp, err := http.Get("http://data.alexa.com/data?cli=10&url=" + domainName)

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

 defer resp.Body.Close()

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

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

 // convert []byte to type io.Reader with strings.NewReader()
 decoder := xml.NewDecoder(strings.NewReader(string(alexaData)))

 // loop till we get REACH token
 for {
 token, _ := decoder.Token()

 if token == nil {
 break
 }

 switch startElement := token.(type) {
 case xml.StartElement:
 if startElement.Name.Local == "REACH" {
 //fmt.Println(startElement.Name)
 //fmt.Println(startElement.Attr[0])
 fmt.Printf("%s has popularity rank of %s \n", domainName, startElement.Attr[0].Value)
 }
 }
 }

 }

Output :

socketloop.com has popularity rank of 237750

NOTE : I've tried to unmarshal the XML but was unsuccessful. Could it be UPPERCASE or too much attributes ? I don't know... seems like a bug to me or is there something wrong with my code? Let me know if you can help to fix the code at http://play.golang.org/p/uOUjX5immw

References :

http://stackoverflow.com/questions/3676376/fetching-alexa-data

https://www.socketloop.com/tutorials/golang-http-get-example

https://golang.org/pkg/encoding/xml/#Attr