gotosocial/vendor/github.com/yuin/goldmark/parser/raw_html.go
Autumn! eb08529f35
[chore/bugfix] Switch markdown from blackfriday to goldmark (#1267)
Co-authored-by: Autumn! <autumnull@posteo.net>
2022-12-16 12:20:22 +01:00

163 lines
4.3 KiB
Go

package parser
import (
"bytes"
"regexp"
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
type rawHTMLParser struct {
}
var defaultRawHTMLParser = &rawHTMLParser{}
// NewRawHTMLParser return a new InlineParser that can parse
// inline htmls
func NewRawHTMLParser() InlineParser {
return defaultRawHTMLParser
}
func (s *rawHTMLParser) Trigger() []byte {
return []byte{'<'}
}
func (s *rawHTMLParser) Parse(parent ast.Node, block text.Reader, pc Context) ast.Node {
line, _ := block.PeekLine()
if len(line) > 1 && util.IsAlphaNumeric(line[1]) {
return s.parseMultiLineRegexp(openTagRegexp, block, pc)
}
if len(line) > 2 && line[1] == '/' && util.IsAlphaNumeric(line[2]) {
return s.parseMultiLineRegexp(closeTagRegexp, block, pc)
}
if bytes.HasPrefix(line, openComment) {
return s.parseComment(block, pc)
}
if bytes.HasPrefix(line, openProcessingInstruction) {
return s.parseUntil(block, closeProcessingInstruction, pc)
}
if len(line) > 2 && line[1] == '!' && line[2] >= 'A' && line[2] <= 'Z' {
return s.parseUntil(block, closeDecl, pc)
}
if bytes.HasPrefix(line, openCDATA) {
return s.parseUntil(block, closeCDATA, pc)
}
return nil
}
var tagnamePattern = `([A-Za-z][A-Za-z0-9-]*)`
var attributePattern = `(?:[\r\n \t]+[a-zA-Z_:][a-zA-Z0-9:._-]*(?:[\r\n \t]*=[\r\n \t]*(?:[^\"'=<>` + "`" + `\x00-\x20]+|'[^']*'|"[^"]*"))?)`
var openTagRegexp = regexp.MustCompile("^<" + tagnamePattern + attributePattern + `*[ \t]*/?>`)
var closeTagRegexp = regexp.MustCompile("^</" + tagnamePattern + `\s*>`)
var openProcessingInstruction = []byte("<?")
var closeProcessingInstruction = []byte("?>")
var openCDATA = []byte("<![CDATA[")
var closeCDATA = []byte("]]>")
var closeDecl = []byte(">")
var emptyComment = []byte("<!---->")
var invalidComment1 = []byte("<!-->")
var invalidComment2 = []byte("<!--->")
var openComment = []byte("<!--")
var closeComment = []byte("-->")
var doubleHyphen = []byte("--")
func (s *rawHTMLParser) parseComment(block text.Reader, pc Context) ast.Node {
savedLine, savedSegment := block.Position()
node := ast.NewRawHTML()
line, segment := block.PeekLine()
if bytes.HasPrefix(line, emptyComment) {
node.Segments.Append(segment.WithStop(segment.Start + len(emptyComment)))
block.Advance(len(emptyComment))
return node
}
if bytes.HasPrefix(line, invalidComment1) || bytes.HasPrefix(line, invalidComment2) {
return nil
}
offset := len(openComment)
line = line[offset:]
for {
hindex := bytes.Index(line, doubleHyphen)
if hindex > -1 {
hindex += offset
}
index := bytes.Index(line, closeComment) + offset
if index > -1 && hindex == index {
if index == 0 || len(line) < 2 || line[index-offset-1] != '-' {
node.Segments.Append(segment.WithStop(segment.Start + index + len(closeComment)))
block.Advance(index + len(closeComment))
return node
}
}
if hindex > 0 {
break
}
node.Segments.Append(segment)
block.AdvanceLine()
line, segment = block.PeekLine()
offset = 0
if line == nil {
break
}
}
block.SetPosition(savedLine, savedSegment)
return nil
}
func (s *rawHTMLParser) parseUntil(block text.Reader, closer []byte, pc Context) ast.Node {
savedLine, savedSegment := block.Position()
node := ast.NewRawHTML()
for {
line, segment := block.PeekLine()
if line == nil {
break
}
index := bytes.Index(line, closer)
if index > -1 {
node.Segments.Append(segment.WithStop(segment.Start + index + len(closer)))
block.Advance(index + len(closer))
return node
}
node.Segments.Append(segment)
block.AdvanceLine()
}
block.SetPosition(savedLine, savedSegment)
return nil
}
func (s *rawHTMLParser) parseMultiLineRegexp(reg *regexp.Regexp, block text.Reader, pc Context) ast.Node {
sline, ssegment := block.Position()
if block.Match(reg) {
node := ast.NewRawHTML()
eline, esegment := block.Position()
block.SetPosition(sline, ssegment)
for {
line, segment := block.PeekLine()
if line == nil {
break
}
l, _ := block.Position()
start := segment.Start
if l == sline {
start = ssegment.Start
}
end := segment.Stop
if l == eline {
end = esegment.Start
}
node.Segments.Append(text.NewSegment(start, end))
if l == eline {
block.Advance(end - start)
break
} else {
block.AdvanceLine()
}
}
return node
}
return nil
}