forgejo/vendor/github.com/yuin/goldmark/extension/linkify.go
2020-02-28 13:06:10 +00:00

304 lines
7.4 KiB
Go

package extension
import (
"bytes"
"regexp"
"github.com/yuin/goldmark"
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/parser"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
var wwwURLRegxp = regexp.MustCompile(`^www\.[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]+(?:(?:/|[#?])[-a-zA-Z0-9@:%_\+.~#!?&//=\(\);,'">\^{}\[\]` + "`" + `]*)?`)
var urlRegexp = regexp.MustCompile(`^(?:http|https|ftp):\/\/(?:www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]+(?:(?:/|[#?])[-a-zA-Z0-9@:%_+.~#$!?&//=\(\);,'">\^{}\[\]` + "`" + `]*)?`)
// An LinkifyConfig struct is a data structure that holds configuration of the
// Linkify extension.
type LinkifyConfig struct {
AllowedProtocols [][]byte
URLRegexp *regexp.Regexp
WWWRegexp *regexp.Regexp
EmailRegexp *regexp.Regexp
}
const optLinkifyAllowedProtocols parser.OptionName = "LinkifyAllowedProtocols"
const optLinkifyURLRegexp parser.OptionName = "LinkifyURLRegexp"
const optLinkifyWWWRegexp parser.OptionName = "LinkifyWWWRegexp"
const optLinkifyEmailRegexp parser.OptionName = "LinkifyEmailRegexp"
// SetOption implements SetOptioner.
func (c *LinkifyConfig) SetOption(name parser.OptionName, value interface{}) {
switch name {
case optLinkifyAllowedProtocols:
c.AllowedProtocols = value.([][]byte)
case optLinkifyURLRegexp:
c.URLRegexp = value.(*regexp.Regexp)
case optLinkifyWWWRegexp:
c.WWWRegexp = value.(*regexp.Regexp)
case optLinkifyEmailRegexp:
c.EmailRegexp = value.(*regexp.Regexp)
}
}
// A LinkifyOption interface sets options for the LinkifyOption.
type LinkifyOption interface {
parser.Option
SetLinkifyOption(*LinkifyConfig)
}
type withLinkifyAllowedProtocols struct {
value [][]byte
}
func (o *withLinkifyAllowedProtocols) SetParserOption(c *parser.Config) {
c.Options[optLinkifyAllowedProtocols] = o.value
}
func (o *withLinkifyAllowedProtocols) SetLinkifyOption(p *LinkifyConfig) {
p.AllowedProtocols = o.value
}
// WithLinkifyAllowedProtocols is a functional option that specify allowed
// protocols in autolinks. Each protocol must end with ':' like
// 'http:' .
func WithLinkifyAllowedProtocols(value [][]byte) LinkifyOption {
return &withLinkifyAllowedProtocols{
value: value,
}
}
type withLinkifyURLRegexp struct {
value *regexp.Regexp
}
func (o *withLinkifyURLRegexp) SetParserOption(c *parser.Config) {
c.Options[optLinkifyURLRegexp] = o.value
}
func (o *withLinkifyURLRegexp) SetLinkifyOption(p *LinkifyConfig) {
p.URLRegexp = o.value
}
// WithLinkifyURLRegexp is a functional option that specify
// a pattern of the URL including a protocol.
func WithLinkifyURLRegexp(value *regexp.Regexp) LinkifyOption {
return &withLinkifyURLRegexp{
value: value,
}
}
// WithLinkifyWWWRegexp is a functional option that specify
// a pattern of the URL without a protocol.
// This pattern must start with 'www.' .
type withLinkifyWWWRegexp struct {
value *regexp.Regexp
}
func (o *withLinkifyWWWRegexp) SetParserOption(c *parser.Config) {
c.Options[optLinkifyWWWRegexp] = o.value
}
func (o *withLinkifyWWWRegexp) SetLinkifyOption(p *LinkifyConfig) {
p.WWWRegexp = o.value
}
func WithLinkifyWWWRegexp(value *regexp.Regexp) LinkifyOption {
return &withLinkifyWWWRegexp{
value: value,
}
}
// WithLinkifyWWWRegexp is a functional otpion that specify
// a pattern of the email address.
type withLinkifyEmailRegexp struct {
value *regexp.Regexp
}
func (o *withLinkifyEmailRegexp) SetParserOption(c *parser.Config) {
c.Options[optLinkifyEmailRegexp] = o.value
}
func (o *withLinkifyEmailRegexp) SetLinkifyOption(p *LinkifyConfig) {
p.EmailRegexp = o.value
}
func WithLinkifyEmailRegexp(value *regexp.Regexp) LinkifyOption {
return &withLinkifyEmailRegexp{
value: value,
}
}
type linkifyParser struct {
LinkifyConfig
}
// NewLinkifyParser return a new InlineParser can parse
// text that seems like a URL.
func NewLinkifyParser(opts ...LinkifyOption) parser.InlineParser {
p := &linkifyParser{
LinkifyConfig: LinkifyConfig{
AllowedProtocols: nil,
URLRegexp: urlRegexp,
WWWRegexp: wwwURLRegxp,
},
}
for _, o := range opts {
o.SetLinkifyOption(&p.LinkifyConfig)
}
return p
}
func (s *linkifyParser) Trigger() []byte {
// ' ' indicates any white spaces and a line head
return []byte{' ', '*', '_', '~', '('}
}
var protoHTTP = []byte("http:")
var protoHTTPS = []byte("https:")
var protoFTP = []byte("ftp:")
var domainWWW = []byte("www.")
func (s *linkifyParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
if pc.IsInLinkLabel() {
return nil
}
line, segment := block.PeekLine()
consumes := 0
start := segment.Start
c := line[0]
// advance if current position is not a line head.
if c == ' ' || c == '*' || c == '_' || c == '~' || c == '(' {
consumes++
start++
line = line[1:]
}
var m []int
var protocol []byte
var typ ast.AutoLinkType = ast.AutoLinkURL
if s.LinkifyConfig.AllowedProtocols == nil {
if bytes.HasPrefix(line, protoHTTP) || bytes.HasPrefix(line, protoHTTPS) || bytes.HasPrefix(line, protoFTP) {
m = s.LinkifyConfig.URLRegexp.FindSubmatchIndex(line)
}
} else {
for _, prefix := range s.LinkifyConfig.AllowedProtocols {
if bytes.HasPrefix(line, prefix) {
m = s.LinkifyConfig.URLRegexp.FindSubmatchIndex(line)
break
}
}
}
if m == nil && bytes.HasPrefix(line, domainWWW) {
m = s.LinkifyConfig.WWWRegexp.FindSubmatchIndex(line)
protocol = []byte("http")
}
if m != nil && m[0] != 0 {
m = nil
}
if m != nil && m[0] == 0 {
lastChar := line[m[1]-1]
if lastChar == '.' {
m[1]--
} else if lastChar == ')' {
closing := 0
for i := m[1] - 1; i >= m[0]; i-- {
if line[i] == ')' {
closing++
} else if line[i] == '(' {
closing--
}
}
if closing > 0 {
m[1] -= closing
}
} else if lastChar == ';' {
i := m[1] - 2
for ; i >= m[0]; i-- {
if util.IsAlphaNumeric(line[i]) {
continue
}
break
}
if i != m[1]-2 {
if line[i] == '&' {
m[1] -= m[1] - i
}
}
}
}
if m == nil {
if len(line) > 0 && util.IsPunct(line[0]) {
return nil
}
typ = ast.AutoLinkEmail
stop := -1
if s.LinkifyConfig.EmailRegexp == nil {
stop = util.FindEmailIndex(line)
} else {
m := s.LinkifyConfig.EmailRegexp.FindSubmatchIndex(line)
if m != nil && m[0] == 0 {
stop = m[1]
}
}
if stop < 0 {
return nil
}
at := bytes.IndexByte(line, '@')
m = []int{0, stop, at, stop - 1}
if m == nil || bytes.IndexByte(line[m[2]:m[3]], '.') < 0 {
return nil
}
lastChar := line[m[1]-1]
if lastChar == '.' {
m[1]--
}
if m[1] < len(line) {
nextChar := line[m[1]]
if nextChar == '-' || nextChar == '_' {
return nil
}
}
}
if m == nil {
return nil
}
if consumes != 0 {
s := segment.WithStop(segment.Start + 1)
ast.MergeOrAppendTextSegment(parent, s)
}
consumes += m[1]
block.Advance(consumes)
n := ast.NewTextSegment(text.NewSegment(start, start+m[1]))
link := ast.NewAutoLink(typ, n)
link.Protocol = protocol
return link
}
func (s *linkifyParser) CloseBlock(parent ast.Node, pc parser.Context) {
// nothing to do
}
type linkify struct {
options []LinkifyOption
}
// Linkify is an extension that allow you to parse text that seems like a URL.
var Linkify = &linkify{}
func NewLinkify(opts ...LinkifyOption) goldmark.Extender {
return &linkify{
options: opts,
}
}
func (e *linkify) Extend(m goldmark.Markdown) {
m.Parser().AddOptions(
parser.WithInlineParsers(
util.Prioritized(NewLinkifyParser(e.options...), 999),
),
)
}