package extension import ( "bytes" "github.com/yuin/goldmark" "github.com/yuin/goldmark/ast" "github.com/yuin/goldmark/parser" "github.com/yuin/goldmark/text" "github.com/yuin/goldmark/util" "regexp" ) var wwwURLRegxp = regexp.MustCompile(`^www\.[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}((?:/|[#?])[-a-zA-Z0-9@:%_\+.~#!?&//=\(\);,'">\^{}\[\]` + "`" + `]*)?`) var urlRegexp = regexp.MustCompile(`^(?:http|https|ftp):\/\/(?:www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}((?:/|[#?])[-a-zA-Z0-9@:%_+.~#$!?&//=\(\);,'">\^{}\[\]` + "`" + `]*)?`) type linkifyParser struct { } var defaultLinkifyParser = &linkifyParser{} // NewLinkifyParser return a new InlineParser can parse // text that seems like a URL. func NewLinkifyParser() parser.InlineParser { return defaultLinkifyParser } 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 bytes.HasPrefix(line, protoHTTP) || bytes.HasPrefix(line, protoHTTPS) || bytes.HasPrefix(line, protoFTP) { m = urlRegexp.FindSubmatchIndex(line) } if m == nil && bytes.HasPrefix(line, domainWWW) { m = wwwURLRegxp.FindSubmatchIndex(line) protocol = []byte("http") } if m != nil { 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 := util.FindEmailIndex(line) 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 { } // Linkify is an extension that allow you to parse text that seems like a URL. var Linkify = &linkify{} func (e *linkify) Extend(m goldmark.Markdown) { m.Parser().AddOptions( parser.WithInlineParsers( util.Prioritized(NewLinkifyParser(), 999), ), ) }