/
webtools.go
65 lines (57 loc) · 1.27 KB
/
webtools.go
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package main
import (
"encoding/xml"
"net/http"
"net/url"
)
type HtmlParser struct {
url *url.URL
}
func NewHtmlParser(baseurl interface{}) *HtmlParser {
switch _baseurl := baseurl.(type) {
case string:
if _url, err := url.Parse(_baseurl); err == nil {
return &HtmlParser{url: _url}
}
case *url.URL:
if _baseurl == nil {
return nil
}
return &HtmlParser{url: _baseurl}
}
return nil
}
func (p *HtmlParser) ExtractLinks() []*url.URL {
var d *xml.Decoder
if reply, err := http.Get(p.url.String()); err != nil {
return nil
} else {
defer reply.Body.Close()
d = xml.NewDecoder(reply.Body)
d.Strict = false
d.AutoClose = xml.HTMLAutoClose
d.Entity = xml.HTMLEntity
}
extractHref := func(aElem xml.StartElement) string {
for _, attr := range aElem.Attr {
if attr.Name.Local == "href" {
return attr.Value
}
}
return ""
}
var links = make([]*url.URL, 0, 32)
for token, err := d.Token(); err == nil; token, err = d.Token() {
if t, ok := token.(xml.StartElement); ok && t.Name.Local == "a" {
if href := extractHref(t); href != "" {
if link, err := url.Parse(href); err == nil {
link = p.url.ResolveReference(link)
link.RawQuery = ""
link.Fragment = ""
links = append(links, link)
}
}
}
}
return links
}