YouTubeCenter Version Checker

ytcenter-check.go

///
// YouTube Center Checker
//
// A very messy golang script to download the chrome manifest from the
// YouTubeCenter (https://github.com/YePpHa/YouTubeCenter) repo and display it
//
// This is more of a learning exercise than a useful utility.

package main

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

const (
  MANIFEST_URL = "https://github.com/YePpHa/YouTubeCenter/raw/master/dist/chrome-update.xml"
)

func main() {
  var manifest *chromeManifest
  var err error

  var flagTest bool
  flag.BoolVar(&flagTest, "test", false, "Use test data, don't contact GitHub")
  flag.Parse()

  if flagTest {
    testData, _ := GetManifestTestXML()
    manifest, err = GetManifest(testData)
  } else {
    manifest, err = GetManifest("")
  }
  if err != nil {
    log.Fatal(err)
  }
  fmt.Println(manifest.App.UpdateCheck.Version)
}

type chromeManifest struct {
  App xmlApp `xml:"app"`
}
type xmlApp struct {
  UpdateCheck updateCheck `xml:"updatecheck"`
}
type updateCheck struct {
  Version string `xml:"version,attr"`
}

// Downloads and unmarshals the manifest
func GetManifest(xmlString string) (manifest *chromeManifest, err error) {
  // var err error
  if xmlString == "" {
    xmlString, err = GetManifestXML()
  }
  if err != nil {
    return manifest, err
  }
  // fmt.Println(xmlString)
  xmlBytes := []byte(xmlString)
  manifest = new(chromeManifest)
  err = xml.Unmarshal(xmlBytes, &manifest)
  return
}

func GetManifestTestXML() (contents string, err error) {
  return `<?xml version="1.0" encoding="UTF-8"?>
<gupdate xmlns="http://www.google.com/update2/response" protocol="2.0">
  <app appid="ajijnmbjgaeekdpmpohgppkckmnagimk">
    <updatecheck codebase="https://raw.github.com/YePpHa/YouTubeCenter/master/dist/YouTubeCenter.crx" version="31337" />
  </app>
</gupdate>`, nil
}
func GetManifestXML() (contents string, err error) {
  if response, err := http.Get(MANIFEST_URL); err != nil {
    return "", err
  } else {
    defer response.Body.Close()

    if xml, err := ioutil.ReadAll(response.Body); err != nil {
      return "", err
    } else {
      contents = fmt.Sprintf("%s\n", string(xml))
    }
  }
  return
}