/
html.go
159 lines (144 loc) · 2.85 KB
/
html.go
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package indexer
import (
"bytes"
"io"
"strings"
"golang.org/x/net/html"
"golang.org/x/net/html/atom"
)
type htmlParser struct {
title string
b bytes.Buffer
noIndex bool // set to true if has meta name="robots" or name="kkr-search" and content="noindex">
}
func (p *htmlParser) parseMeta(n *html.Node) {
consume := false
robots := false
for _, a := range n.Attr {
if a.Key == "name" {
v := strings.ToLower(a.Val)
if v == "keywords" || v == "description" {
consume = true
} else if v == "robots" || v == "kkr-search" {
robots = true
}
}
}
if !consume && !robots {
return
}
for _, a := range n.Attr {
if a.Key == "content" {
if consume {
p.consumeString(a.Val)
} else if robots {
p.noIndex = false
}
}
}
}
func (p *htmlParser) skipNoIndexElement(n *html.Node) bool {
for _, a := range n.Attr {
if a.Key == "data-kkr-search" {
v := strings.ToLower(a.Val)
if v == "noindex" {
return true
}
}
}
return false
}
func (p *htmlParser) parseImg(n *html.Node) {
for _, a := range n.Attr {
if a.Key == "alt" || a.Key == "title" {
p.consumeString(a.Val)
return
}
}
}
func (p *htmlParser) parseTitle(n *html.Node) {
if c := n.FirstChild; c != nil && c.Type == html.TextNode {
p.title = c.Data
}
}
func (p *htmlParser) consumeString(s string) {
p.b.WriteString(s)
p.b.WriteByte('\n')
}
func (p *htmlParser) parseNoscript(n *html.Node) {
c := n.FirstChild
if c == nil {
return
}
nodes, err := html.ParseFragment(strings.NewReader(c.Data), nil)
if err != nil {
return // ignore error
}
for _, v := range nodes {
p.parseNode(v)
}
}
func (p *htmlParser) parseNode(n *html.Node) {
if p.noIndex {
return
}
switch n.Type {
case html.DocumentNode:
// Parse children
if c := n.FirstChild; c != nil {
p.parseNode(c)
}
case html.ElementNode:
switch n.DataAtom {
case atom.Title:
p.parseTitle(n)
case atom.Meta:
p.parseMeta(n)
case atom.Img:
p.parseImg(n)
case atom.Noscript:
// Parse insides of noscript as HTML.
p.parseNoscript(n)
case atom.Script, atom.Style:
// skip children
default:
if !p.skipNoIndexElement(n) {
// Parse children
if c := n.FirstChild; c != nil {
p.parseNode(c)
}
}
}
case html.TextNode:
p.consumeString(n.Data)
}
// Parse sibling.
if c := n.NextSibling; c != nil {
p.parseNode(c)
}
}
func (p *htmlParser) Parse(r io.Reader) error {
doc, err := html.Parse(r)
if err != nil {
return err
}
p.parseNode(doc)
return nil
}
func (p *htmlParser) Content() string {
return p.b.String()
}
func (p *htmlParser) Title() string {
return p.title
}
func (p *htmlParser) IsIndexable() bool {
return !p.noIndex
}
func parseHTML(r io.Reader) (title, content string, indexable bool, err error) {
var p htmlParser
err = p.Parse(r)
if err != nil {
return
}
return p.Title(), p.Content(), p.IsIndexable(), nil
}