diff --git a/posts/parse.go b/posts/parse.go index 0d61bac..6c179ce 100644 --- a/posts/parse.go +++ b/posts/parse.go @@ -1,209 +1,210 @@ package posts import ( "fmt" stripmd "github.com/writeas/go-strip-markdown/v2" "github.com/writeas/slug" "github.com/writeas/web-core/stringmanip" "regexp" "strings" "unicode" "unicode/utf8" ) const ( maxTitleLen = 80 assumedTitleLen = 80 ) var ( titleElementReg = regexp.MustCompile("") urlReg = regexp.MustCompile("https?://") imgReg = regexp.MustCompile(`!\[([^]]+)\]\([^)]+\)`) ) // ExtractTitle takes the given raw post text and returns a title, if explicitly // provided, and a body. func ExtractTitle(content string) (title string, body string) { if hashIndex := strings.Index(content, "# "); hashIndex == 0 { eol := strings.IndexRune(content, '\n') // First line should start with # and end with \n if eol != -1 { body = strings.TrimLeft(content[eol:], " \t\n\r") title = content[len("# "):eol] return } } body = content return } func PostTitle(content, friendlyId string) string { content = StripHTMLWithoutEscaping(content) content = strings.TrimLeftFunc(stripmd.Strip(content), unicode.IsSpace) eol := strings.IndexRune(content, '\n') blankLine := strings.Index(content, "\n\n") if blankLine != -1 && blankLine <= eol && blankLine <= assumedTitleLen { return strings.TrimSpace(content[:blankLine]) } else if utf8.RuneCountInString(content) <= maxTitleLen { return content } return friendlyId } func FriendlyPostTitle(content, friendlyId string) string { content = StripHTMLWithoutEscaping(content) content = strings.TrimLeftFunc(stripmd.Strip(content), unicode.IsSpace) eol := strings.IndexRune(content, '\n') blankLine := strings.Index(content, "\n\n") if blankLine != -1 && blankLine <= eol && blankLine <= assumedTitleLen { return strings.TrimSpace(content[:blankLine]) } else if eol == -1 && utf8.RuneCountInString(content) <= maxTitleLen { return content } title, truncd := TruncToWord(PostLede(content, true), maxTitleLen) if truncd { title += "..." } return title } // PostDescription generates a description based on the given post content, // title, and post ID. This doesn't consider a V2 post field, `title` when // choosing what to generate. In case a post has a title, this function will // fail, and logic should instead be implemented to skip this when there's no // title, like so: -// var desc string -// if title == "" { -// desc = PostDescription(content, title, friendlyId) -// } else { -// desc = ShortPostDescription(content) -// } +// +// var desc string +// if title == "" { +// desc = PostDescription(content, title, friendlyId) +// } else { +// desc = ShortPostDescription(content) +// } func PostDescription(content, title, friendlyId string) string { maxLen := 140 if content == "" { content = "WriteFreely is a painless, simple, federated blogging platform." } else { fmtStr := "%s" truncation := 0 if utf8.RuneCountInString(content) > maxLen { // Post is longer than the max description, so let's show a better description fmtStr = "%s..." truncation = 3 } if title == friendlyId { // No specific title was found; simply truncate the post, starting at the beginning content = fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1)) } else { // There was a title, so return a real description blankLine := strings.Index(content, "\n\n") if blankLine < 0 { blankLine = 0 } truncd := stringmanip.Substring(content, blankLine, blankLine+maxLen-truncation) contentNoNL := strings.Replace(truncd, "\n", " ", -1) content = strings.TrimSpace(fmt.Sprintf(fmtStr, contentNoNL)) } } return content } func ShortPostDescription(content string) string { maxLen := 140 fmtStr := "%s" truncation := 0 if utf8.RuneCountInString(content) > maxLen { // Post is longer than the max description, so let's show a better description fmtStr = "%s..." truncation = 3 } return strings.TrimSpace(fmt.Sprintf(fmtStr, strings.Replace(stringmanip.Substring(content, 0, maxLen-truncation), "\n", " ", -1))) } // TruncToWord truncates the given text to the provided limit. func TruncToWord(s string, l int) (string, bool) { truncated := false c := []rune(s) if len(c) > l { truncated = true s = string(c[:l]) spaceIdx := strings.LastIndexByte(s, ' ') if spaceIdx > -1 { s = s[:spaceIdx] } } return s, truncated } // PostLede attempts to extract the first thought of the given post, generally // contained within the first line or sentence of text. func PostLede(t string, includePunc bool) string { // Adjust where we truncate if we want to include punctuation iAdj := 0 if includePunc { iAdj = 1 } // Find lede within first line of text nl := strings.IndexRune(t, '\n') if nl > -1 { t = t[:nl] } // Strip certain HTML tags t = titleElementReg.ReplaceAllString(t, "") // Strip URL protocols t = urlReg.ReplaceAllString(t, "") // Strip image URL, leaving only alt text t = imgReg.ReplaceAllString(t, " $1 ") // Find lede within first sentence punc := strings.Index(t, ". ") if punc > -1 { t = t[:punc+iAdj] } punc = stringmanip.IndexRune(t, '。') if punc > -1 { c := []rune(t) t = string(c[:punc+iAdj]) } return t } func GetSlug(title, lang string) string { return GetSlugFromPost("", title, lang) } func GetSlugFromPost(title, body, lang string) string { if title == "" { // Remove Markdown, so e.g. link URLs and image alt text don't make it into the slug body = strings.TrimSpace(stripmd.StripOptions(body, stripmd.Options{SkipImages: true})) title = PostTitle(body, body) } title = PostLede(title, false) // Truncate lede if needed title, _ = TruncToWord(title, maxTitleLen) var s string if lang != "" && len(lang) == 2 { s = slug.MakeLang(title, lang) } else { s = slug.Make(title) } // Transliteration may cause the slug to expand past the limit, so truncate again s, _ = TruncToWord(s, maxTitleLen) return strings.TrimFunc(s, func(r rune) bool { // TruncToWord doesn't respect words in a slug, since spaces are replaced // with hyphens. So remove any trailing hyphens. return r == '-' }) }