107 lines
2.4 KiB
Go
107 lines
2.4 KiB
Go
// Copyright 2017 Frédéric Guillot. All rights reserved.
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// Use of this source code is governed by the Apache 2.0
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// license that can be found in the LICENSE file.
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package scraper // import "miniflux.app/reader/scraper"
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import (
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"errors"
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"fmt"
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"io"
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"strings"
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"miniflux.app/http/client"
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"miniflux.app/logger"
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"miniflux.app/reader/readability"
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"miniflux.app/url"
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"github.com/PuerkitoBio/goquery"
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)
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// Fetch downloads a web page and returns relevant contents.
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func Fetch(websiteURL, rules, userAgent string) (string, error) {
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clt := client.New(websiteURL)
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if userAgent != "" {
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clt.WithUserAgent(userAgent)
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}
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response, err := clt.Get()
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if err != nil {
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return "", err
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}
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if response.HasServerFailure() {
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return "", errors.New("scraper: unable to download web page")
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}
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if !isWhitelistedContentType(response.ContentType) {
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return "", fmt.Errorf("scraper: this resource is not a HTML document (%s)", response.ContentType)
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}
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if err = response.EnsureUnicodeBody(); err != nil {
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return "", err
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}
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// The entry URL could redirect somewhere else.
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websiteURL = response.EffectiveURL
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if rules == "" {
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rules = getPredefinedScraperRules(websiteURL)
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}
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var content string
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if rules != "" {
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logger.Debug(`[Scraper] Using rules %q for %q`, rules, websiteURL)
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content, err = scrapContent(response.Body, rules)
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} else {
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logger.Debug(`[Scraper] Using readability for %q`, websiteURL)
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content, err = readability.ExtractContent(response.Body)
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}
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if err != nil {
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return "", err
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}
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return content, nil
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}
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func scrapContent(page io.Reader, rules string) (string, error) {
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document, err := goquery.NewDocumentFromReader(page)
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if err != nil {
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return "", err
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}
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contents := ""
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document.Find(rules).Each(func(i int, s *goquery.Selection) {
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var content string
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// For some inline elements, we get the parent.
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if s.Is("img") || s.Is("iframe") {
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content, _ = s.Parent().Html()
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} else {
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content, _ = s.Html()
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}
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contents += content
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})
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return contents, nil
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}
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func getPredefinedScraperRules(websiteURL string) string {
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urlDomain := url.Domain(websiteURL)
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for domain, rules := range predefinedRules {
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if strings.Contains(urlDomain, domain) {
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return rules
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}
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}
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return ""
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}
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func isWhitelistedContentType(contentType string) bool {
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contentType = strings.ToLower(contentType)
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return strings.HasPrefix(contentType, "text/html") ||
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strings.HasPrefix(contentType, "application/xhtml+xml")
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}
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