*: Reorganize code

parser/confluencetags.go

@@ -0,0 +1,114 @@
+package parser
+
+import (
+	"bytes"
+	"regexp"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+// NewConfluenceTagParser returns an inline parser that parses <ac:* /> and <ri:* /> tags to ensure that Confluence specific tags are parsed
+// as ast.KindRawHtml so they are not escaped at render time. The parser must be registered with a higher priority
+// than goldmark's linkParser. Otherwise, the linkParser would parse the <ac:* /> tags.
+func NewConfluenceTagParser() parser.InlineParser {
+	return &confluenceTagParser{}
+}
+
+var _ parser.InlineParser = (*confluenceTagParser)(nil)
+
+// confluenceTagParser is a stripped down version of goldmark's rawHTMLParser.
+// See: https://github.com/yuin/goldmark/blob/master/parser/raw_html.go
+type confluenceTagParser struct {
+}
+
+func (s *confluenceTagParser) Trigger() []byte {
+	return []byte{'<'}
+}
+
+func (s *confluenceTagParser) Parse(_ ast.Node, block text.Reader, pc parser.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 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 spaceOrOneNewline = `(?:[ \t]|(?:\r\n|\n){0,1})`
+var attributePattern = `(?:[\r\n \t]+[a-zA-Z_:][a-zA-Z0-9:._-]*(?:[\r\n \t]*=[\r\n \t]*(?:[^\"'=<>` + "`" + `\x00-\x20]+|'[^']*'|"[^"]*"))?)`
+
+// Only match <ac:*/> and <ri:*/> tags
+var openTagRegexp = regexp.MustCompile("^<(ac|ri):" + tagnamePattern + attributePattern + `*` + spaceOrOneNewline + `*/?>`)
+var closeTagRegexp = regexp.MustCompile("^</ac:" + tagnamePattern + spaceOrOneNewline + `*>`)
+
+var openCDATA = []byte("<![CDATA[")
+var closeCDATA = []byte("]]>")
+var closeDecl = []byte(">")
+
+func (s *confluenceTagParser) parseUntil(block text.Reader, closer []byte, _ parser.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 *confluenceTagParser) parseMultiLineRegexp(reg *regexp.Regexp, block text.Reader, _ parser.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
+}