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fix: use TagAttr and move trim space to sanitization

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This commit is contained in:
yinebebt
2024-12-02 13:06:53 +03:00
parent 49f7b809fd
commit 3fbfc5ceef
1 changed files with 39 additions and 27 deletions
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66
server/linkpreview.go
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@ -86,11 +86,13 @@ func previewLink(w http.ResponseWriter, r *http.Request) {
if cc := resp.Header.Get("Cache-Control"); cc != "" {
w.Header().Set("Cache-Control", cc)
}
w.Header().Set("Content-Type", "application/json")
if r.Method == http.MethodHead {
w.WriteHeader(http.StatusOK)
return
}
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(extractMetadata(body)); err != nil {
http.Error(w, "Failed to encode response", http.StatusInternalServerError)
}
@ -101,50 +103,60 @@ func extractMetadata(body io.Reader) *linkPreview {
var inTitleTag bool
tokenizer := html.NewTokenizer(body)
lp:
for {
switch tokenizer.Next() {
case html.ErrorToken:
return sanitizePreview(preview)
break lp
case html.StartTagToken, html.SelfClosingTagToken:
token := tokenizer.Token()
if token.DataAtom == atom.Meta {
tag, hasAttr := tokenizer.TagName()
tagName := atom.Lookup(tag)
if tagName == atom.Meta && hasAttr {
var name, property, content string
for _, attr := range token.Attr {
switch attr.Key {
for {
key, val, moreAttr := tokenizer.TagAttr()
switch atom.String(key) {
case "name":
name = attr.Val
name = string(val)
case "property":
property = attr.Val
property = string(val)
case "content":
content = attr.Val
content = string(val)
}
if !moreAttr {
break
}
}
if strings.HasPrefix(property, "og:") && content != "" {
switch property {
case "og:title":
preview.Title = content
case "og:description":
if content != "" {
if strings.HasPrefix(property, "og:") {
switch property {
case "og:title":
preview.Title = content
case "og:description":
preview.Description = content
case "og:image":
preview.ImageURL = content
}
} else if name == "description" && preview.Description == "" {
preview.Description = content
case "og:image":
preview.ImageURL = content
}
} else if name == "description" && preview.Description == "" {
preview.Description = content
}
} else if token.DataAtom == atom.Title {
} else if tagName == atom.Title {
inTitleTag = true
}
case html.TextToken:
if preview.Title == "" && inTitleTag {
preview.Title = strings.TrimSpace(tokenizer.Token().Data)
}
case html.EndTagToken:
if tokenizer.Token().DataAtom == atom.Title {
if inTitleTag {
if preview.Title == "" {
preview.Title = tokenizer.Token().Data
}
inTitleTag = false
}
case html.EndTagToken:
inTitleTag = false
}
if preview.Title != "" && preview.Description != "" && preview.ImageURL != "" {
break
@ -174,13 +186,13 @@ func validateURL(u *url.URL) error {
func sanitizePreview(preview linkPreview) *linkPreview {
if utf8.RuneCountInString(preview.Title) > 80 {
preview.Title = string([]rune(preview.Title)[:80])
preview.Title = string([]rune(strings.TrimSpace(preview.Title))[:80])
}
if utf8.RuneCountInString(preview.Description) > 256 {
preview.Description = string([]rune(preview.Description)[:256])
preview.Description = string([]rune(strings.TrimSpace(preview.Description))[:256])
}
if len(preview.ImageURL) > 2000 {
preview.ImageURL = preview.ImageURL[:2000]
preview.ImageURL = strings.TrimSpace(preview.ImageURL)[:2000]
}
return &preview