package getter import ( "fmt" "io" "net/http" "net/url" "golang.org/x/net/html" "golang.org/x/net/html/atom" ) type HTMLMeta struct { Title string `json:"title"` Description string `json:"description"` Image string `json:"image"` } func GetHTMLMeta(urlStr string) (*HTMLMeta, error) { if _, err := url.Parse(urlStr); err != nil { return nil, err } response, err := http.Get(urlStr) if err != nil { return nil, err } defer response.Body.Close() mediatype, err := getMediatype(response) if err != nil { return nil, err } if mediatype != "text/html" { return nil, fmt.Errorf("Wrong website mediatype") } htmlMeta := extractHTMLMeta(response.Body) return htmlMeta, nil } func extractHTMLMeta(resp io.Reader) *HTMLMeta { tokenizer := html.NewTokenizer(resp) htmlMeta := new(HTMLMeta) for { tokenType := tokenizer.Next() if tokenType == html.ErrorToken { break } else if tokenType == html.StartTagToken || tokenType == html.SelfClosingTagToken { token := tokenizer.Token() if token.DataAtom == atom.Body { break } if token.DataAtom == atom.Title { tokenizer.Next() token := tokenizer.Token() htmlMeta.Title = token.Data } else if token.DataAtom == atom.Meta { description, ok := extractMetaProperty(token, "description") if ok { htmlMeta.Description = description } ogTitle, ok := extractMetaProperty(token, "og:title") if ok { htmlMeta.Title = ogTitle } ogDescription, ok := extractMetaProperty(token, "og:description") if ok { htmlMeta.Description = ogDescription } ogImage, ok := extractMetaProperty(token, "og:image") if ok { htmlMeta.Image = ogImage } } } } return htmlMeta } func extractMetaProperty(token html.Token, prop string) (content string, ok bool) { content, ok = "", false for _, attr := range token.Attr { if attr.Key == "property" && attr.Val == prop { ok = true } if attr.Key == "content" { content = attr.Val } } return content, ok }