writefreely/parse/posts.go

92 lines
2.1 KiB
Go

/*
* Copyright © 2018-2020 Musing Studio LLC.
*
* This file is part of WriteFreely.
*
* WriteFreely is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, included
* in the LICENSE file in this source code package.
*/
// Package parse assists in the parsing of plain text posts
package parse
import (
"github.com/writeas/web-core/stringmanip"
"regexp"
"strings"
)
var (
titleElementReg = regexp.MustCompile("</?p>")
urlReg = regexp.MustCompile("https?://")
imgReg = regexp.MustCompile(`!\[([^]]+)\]\([^)]+\)`)
)
// 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])
}
punc = stringmanip.IndexRune(t, '?')
if punc > -1 {
c := []rune(t)
t = string(c[:punc+iAdj])
}
return t
}
// 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
}
// Truncate truncates the given text to the provided limit, returning the original string if it's shorter than the limit.
func Truncate(s string, l int) string {
c := []rune(s)
if len(c) > l {
s = string(c[:l])
}
return s
}