//
// Blackfriday Markdown Processor
// Available at http://github.com/russross/blackfriday
//
// Copyright © 2011 Russ Ross <russ@russross.com>.
// Distributed under the Simplified BSD License.
// See README.md for details.
//
//
//
// HTML rendering backend
//
//
package blackfriday
import (
"bytes"
"fmt"
"io"
"regexp"
"strings"
)
// HTMLFlags control optional behavior of HTML renderer.
type HTMLFlags int
// HTML renderer configuration options.
const (
HTMLFlagsNone HTMLFlags = 0
SkipHTML HTMLFlags = 1 << iota // Skip preformatted HTML blocks
SkipImages // Skip embedded images
SkipLinks // Skip all links
Safelink // Only link to trusted protocols
NofollowLinks // Only link with rel="nofollow"
NoreferrerLinks // Only link with rel="noreferrer"
NoopenerLinks // Only link with rel="noopener"
HrefTargetBlank // Add a blank target
CompletePage // Generate a complete HTML page
UseXHTML // Generate XHTML output instead of HTML
FootnoteReturnLinks // Generate a link at the end of a footnote to return to the source
Smartypants // Enable smart punctuation substitutions
SmartypantsFractions // Enable smart fractions (with Smartypants)
SmartypantsDashes // Enable smart dashes (with Smartypants)
SmartypantsLatexDashes // Enable LaTeX-style dashes (with Smartypants)
SmartypantsAngledQuotes // Enable angled double quotes (with Smartypants) for double quotes rendering
SmartypantsQuotesNBSP // Enable « French guillemets » (with Smartypants)
TOC // Generate a table of contents
)
var (
htmlTagRe = regexp.MustCompile("(?i)^" + htmlTag)
)
const (
htmlTag = "(?:" + openTag + "|" + closeTag + "|" + htmlComment + "|" +
processingInstruction + "|" + declaration + "|" + cdata + ")"
closeTag = "</" + tagName + "\\s*[>]"
openTag = "<" + tagName + attribute + "*" + "\\s*/?>"
attribute = "(?:" + "\\s+" + attributeName + attributeValueSpec + "?)"
attributeValue = "(?:" + unquotedValue + "|" + singleQuotedValue + "|" + doubleQuotedValue + ")"
attributeValueSpec = "(?:" + "\\s*=" + "\\s*" + attributeValue + ")"
attributeName = "[a-zA-Z_:][a-zA-Z0-9:._-]*"
cdata = "<!\\[CDATA\\[[\\s\\S]*?\\]\\]>"
declaration = "<![A-Z]+" + "\\s+[^>]*>"
doubleQuotedValue = "\"[^\"]*\""
htmlComment = "<!---->|<!--(?:-?[^>-])(?:-?[^-])*-->"
processingInstruction = "[<][?].*?[?][>]"
singleQuotedValue = "'[^']*'"
tagName = "[A-Za-z][A-Za-z0-9-]*"
unquotedValue = "[^\"'=<>`\\x00-\\x20]+"
)
// HTMLRendererParameters is a collection of supplementary parameters tweaking
// the behavior of various parts of HTML renderer.
type HTMLRendererParameters struct {
// Prepend this text to each relative URL.
AbsolutePrefix string
// Add this text to each footnote anchor, to ensure uniqueness.
FootnoteAnchorPrefix string
// Show this text inside the <a> tag for a footnote return link, if the
// HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
// <sup>[return]</sup> is used.
FootnoteReturnLinkContents string
// If set, add this text to the front of each Heading ID, to ensure
// uniqueness.
HeadingIDPrefix string
// If set, add this text to the back of each Heading ID, to ensure uniqueness.
HeadingIDSuffix string
// Increase heading levels: if the offset is 1, <h1> becomes <h2> etc.
// Negative offset is also valid.
// Resulting levels are clipped between 1 and 6.
HeadingLevelOffset int
Title string // Document title (used if CompletePage is set)
CSS string // Optional CSS file URL (used if CompletePage is set)
Icon string // Optional icon file URL (used if CompletePage is set)
Flags HTMLFlags // Flags allow customizing this renderer's behavior
}
// HTMLRenderer is a type that implements the Renderer interface for HTML output.
//
// Do not create this directly, instead use the NewHTMLRenderer function.
type HTMLRenderer struct {
HTMLRendererParameters
closeTag string // how to end singleton tags: either " />" or ">"
// Track heading IDs to prevent ID collision in a single generation.
headingIDs map[string]int
lastOutputLen int
disableTags int
sr *SPRenderer
}
const (
xhtmlClose = " />"
htmlClose = ">"
)
// NewHTMLRenderer creates and configures an HTMLRenderer object, which
// satisfies the Renderer interface.
func NewHTMLRenderer(params HTMLRendererParameters) *HTMLRenderer {
// configure the rendering engine
closeTag := htmlClose
if params.Flags&UseXHTML != 0 {
closeTag = xhtmlClose
}
if params.FootnoteReturnLinkContents == "" {
// U+FE0E is VARIATION SELECTOR-15.
// It suppresses automatic emoji presentation of the preceding
// U+21A9 LEFTWARDS ARROW WITH HOOK on iOS and iPadOS.
params.FootnoteReturnLinkContents = "<span aria-label='Return'>↩\ufe0e</span>"
}
return &HTMLRenderer{
HTMLRendererParameters: params,
closeTag: closeTag,
headingIDs: make(map[string]int),
sr: NewSmartypantsRenderer(params.Flags),
}
}
func isHTMLTag(tag []byte, tagname string) bool {
found, _ := findHTMLTagPos(tag, tagname)
return found
}
// Look for a character, but ignore it when it's in any kind of quotes, it
// might be JavaScript
func skipUntilCharIgnoreQuotes(html []byte, start int, char byte) int {
inSingleQuote := false
inDoubleQuote := false
inGraveQuote := false
i := start
for i < len(html) {
switch {
case html[i] == char && !inSingleQuote && !inDoubleQuote && !inGraveQuote:
return i
case html[i] == '\'':
inSingleQuote = !inSingleQuote
case html[i] == '"':
inDoubleQuote = !inDoubleQuote
case html[i] == '`':
inGraveQuote = !inGraveQuote
}
i++
}
return start
}
func findHTMLTagPos(tag []byte, tagname string) (bool, int) {
i := 0
if i < len(tag) && tag[0] != '<' {
return false, -1
}
i++
i = skipSpace(tag, i)
if i < len(tag) && tag[i] == '/' {
i++
}
i = skipSpace(tag, i)
j := 0
for ; i < len(tag); i, j = i+1, j+1 {
if j >= len(tagname) {
break
}
if strings.ToLower(string(tag[i]))[0] != tagname[j] {
return false, -1
}
}
if i == len(tag) {
return false, -1
}
rightAngle := skipUntilCharIgnoreQuotes(tag, i, '>')
if rightAngle >= i {
return true, rightAngle
}
return false, -1
}
func skipSpace(tag []byte, i int) int {
for i < len(tag) && isspace(tag[i]) {
i++
}
return i
}
func isRelativeLink(link []byte) (yes bool) {
// a tag begin with '#'
if link[0] == '#' {
return true
}
// link begin with '/' but not '//', the second maybe a protocol relative link
if len(link) >= 2 && link[0] == '/' && link[1] != '/' {
return true
}
// only the root '/'
if len(link) == 1 && link[0] == '/' {
return true
}
// current directory : begin with "./"
if bytes.HasPrefix(link, []byte("./")) {
return true
}
// parent directory : begin with "../"
if bytes.HasPrefix(link, []byte("../")) {
return true
}
return false
}
func (r *HTMLRenderer) ensureUniqueHeadingID(id string) string {
for count, found := r.headingIDs[id]; found; count, found = r.headingIDs[id] {
tmp := fmt.Sprintf("%s-%d", id, count+1)
if _, tmpFound := r.headingIDs[tmp]; !tmpFound {
r.headingIDs[id] = count + 1
id = tmp
} else {
id = id + "-1"
}
}
if _, found := r.headingIDs[id]; !found {
r.headingIDs[id] = 0
}
return id
}
func (r *HTMLRenderer) addAbsPrefix(link []byte) []byte {
if r.AbsolutePrefix != "" && isRelativeLink(link) && link[0] != '.' {
newDest := r.AbsolutePrefix
if link[0] != '/' {
newDest += "/"
}
newDest += string(link)
return []byte(newDest)
}
return link
}
func appendLinkAttrs(attrs []string, flags HTMLFlags, link []byte) []string {
if isRelativeLink(link) {
return attrs
}
val := []string{}
if flags&NofollowLinks != 0 {
val = append(val, "nofollow")
}
if flags&NoreferrerLinks != 0 {
val = append(val, "noreferrer")
}
if flags&NoopenerLinks != 0 {
val = append(val, "noopener")
}
if flags&HrefTargetBlank != 0 {
attrs = append(attrs, "target=\"_blank\"")
}
if len(val) == 0 {
return attrs
}
attr := fmt.Sprintf("rel=%q", strings.Join(val, " "))
return append(attrs, attr)
}
func isMailto(link []byte) bool {
return bytes.HasPrefix(link, []byte("mailto:"))
}
func needSkipLink(flags HTMLFlags, dest []byte) bool {
if flags&SkipLinks != 0 {
return true
}
return flags&Safelink != 0 && !isSafeLink(dest) && !isMailto(dest)
}
func isSmartypantable(node *Node) bool {
pt := node.Parent.Type
return pt != Link && pt != CodeBlock && pt != Code
}
func appendLanguageAttr(attrs []string, info []byte) []string {
if len(info) == 0 {
return attrs
}
endOfLang := bytes.IndexAny(info, "\t ")
if endOfLang < 0 {
endOfLang = len(info)
}
return append(attrs, fmt.Sprintf("class=\"language-%s\"", info[:endOfLang]))
}
func (r *HTMLRenderer) tag(w io.Writer, name []byte, attrs []string) {
w.Write(name)
if len(attrs) > 0 {
w.Write(spaceBytes)
w.Write([]byte(strings.Join(attrs, " ")))
}
w.Write(gtBytes)
r.lastOutputLen = 1
}
func footnoteRef(prefix string, node *Node) []byte {
urlFrag := prefix + string(slugify(node.Destination))
anchor := fmt.Sprintf(`<a href="#fn:%s">%d</a>`, urlFrag, node.NoteID)
return []byte(fmt.Sprintf(`<sup class="footnote-ref" id="fnref:%s">%s</sup>`, urlFrag, anchor))
}
func footnoteItem(prefix string, slug []byte) []byte {
return []byte(fmt.Sprintf(`<li id="fn:%s%s">`, prefix, slug))
}
func footnoteReturnLink(prefix, returnLink string, slug []byte) []byte {
const format = ` <a class="footnote-return" href="#fnref:%s%s">%s</a>`
return []byte(fmt.Sprintf(format, prefix, slug, returnLink))
}
func itemOpenCR(node *Node) bool {
if node.Prev == nil {
return false
}
ld := node.Parent.ListData
return !ld.Tight && ld.ListFlags&ListTypeDefinition == 0
}
func skipParagraphTags(node *Node) bool {
grandparent := node.Parent.Parent
if grandparent == nil || grandparent.Type != List {
return false
}
tightOrTerm := grandparent.Tight || node.Parent.ListFlags&ListTypeTerm != 0
return grandparent.Type == List && tightOrTerm
}
func cellAlignment(align CellAlignFlags) string {
switch align {
case TableAlignmentLeft:
return "left"
case TableAlignmentRight:
return "right"
case TableAlignmentCenter:
return "center"
default:
return ""
}
}
func (r *HTMLRenderer) out(w io.Writer, text []byte) {
if r.disableTags > 0 {
w.Write(htmlTagRe.ReplaceAll(text, []byte{}))
} else {
w.Write(text)
}
r.lastOutputLen = len(text)
}
func (r *HTMLRenderer) cr(w io.Writer) {
if r.lastOutputLen > 0 {
r.out(w, nlBytes)
}
}
var (
nlBytes = []byte{'\n'}
gtBytes = []byte{'>'}
spaceBytes = []byte{' '}
)
var (
brTag = []byte("<br>")
brXHTMLTag = []byte("<br />")
emTag = []byte("<em>")
emCloseTag = []byte("</em>")
strongTag = []byte("<strong>")
strongCloseTag = []byte("</strong>")
delTag = []byte("<del>")
delCloseTag = []byte("</del>")
ttTag = []byte("<tt>")
ttCloseTag = []byte("</tt>")
aTag = []byte("<a")
aCloseTag = []byte("</a>")
preTag = []byte("<pre>")
preCloseTag = []byte("</pre>")
codeTag = []byte("<code>")
codeCloseTag = []byte("</code>")
pTag = []byte("<p>")
pCloseTag = []byte("</p>")
blockquoteTag = []byte("<blockquote>")
blockquoteCloseTag = []byte("</blockquote>")
hrTag = []byte("<hr>")
hrXHTMLTag = []byte("<hr />")
ulTag = []byte("<ul>")
ulCloseTag = []byte("</ul>")
olTag = []byte("<ol>")
olCloseTag = []byte("</ol>")
dlTag = []byte("<dl>")
dlCloseTag = []byte("</dl>")
liTag = []byte("<li>")
liCloseTag = []byte("</li>")
ddTag = []byte("<dd>")
ddCloseTag = []byte("</dd>")
dtTag = []byte("<dt>")
dtCloseTag = []byte("</dt>")
tableTag = []byte("<table>")
tableCloseTag = []byte("</table>")
tdTag = []byte("<td")
tdCloseTag = []byte("</td>")
thTag = []byte("<th")
thCloseTag = []byte("</th>")
theadTag = []byte("<thead>")
theadCloseTag = []byte("</thead>")
tbodyTag = []byte("<tbody>")
tbodyCloseTag = []byte("</tbody>")
trTag = []byte("<tr>")
trCloseTag = []byte("</tr>")
h1Tag = []byte("<h1")
h1CloseTag = []byte("</h1>")
h2Tag = []byte("<h2")
h2CloseTag = []byte("</h2>")
h3Tag = []byte("<h3")
h3CloseTag = []byte("</h3>")
h4Tag = []byte("<h4")
h4CloseTag = []byte("</h4>")
h5Tag = []byte("<h5")
h5CloseTag = []byte("</h5>")
h6Tag = []byte("<h6")
h6CloseTag = []byte("</h6>")
footnotesDivBytes = []byte("\n<div class=\"footnotes\">\n\n")
footnotesCloseDivBytes = []byte("\n</div>\n")
)
func headingTagsFromLevel(level int) ([]byte, []byte) {
if level <= 1 {
return h1Tag, h1CloseTag
}
switch level {
case 2:
return h2Tag, h2CloseTag
case 3:
return h3Tag, h3CloseTag
case 4:
return h4Tag, h4CloseTag
case 5:
return h5Tag, h5CloseTag
}
return h6Tag, h6CloseTag
}
func (r *HTMLRenderer) outHRTag(w io.Writer) {
if r.Flags&UseXHTML == 0 {
r.out(w, hrTag)
} else {
r.out(w, hrXHTMLTag)
}
}
// RenderNode is a default renderer of a single node of a syntax tree. For
// block nodes it will be called twice: first time with entering=true, second
// time with entering=false, so that it could know when it's working on an open
// tag and when on close. It writes the result to w.
//
// The return value is a way to tell the calling walker to adjust its walk
// pattern: e.g. it can terminate the traversal by returning Terminate. Or it
// can ask the walker to skip a subtree of this node by returning SkipChildren.
// The typical behavior is to return GoToNext, which asks for the usual
// traversal to the next node.
func (r *HTMLRenderer) RenderNode(w io.Writer, node *Node, entering bool) WalkStatus {
attrs := []string{}
switch node.Type {
case Text:
if r.Flags&Smartypants != 0 {
var tmp bytes.Buffer
escapeHTML(&tmp, node.Literal)
r.sr.Process(w, tmp.Bytes())
} else {
if node.Parent.Type == Link {
escLink(w, node.Literal)
} else {
escapeHTML(w, node.Literal)
}
}
case Softbreak:
r.cr(w)
// TODO: make it configurable via out(renderer.softbreak)
case Hardbreak:
if r.Flags&UseXHTML == 0 {
r.out(w, brTag)
} else {
r.out(w, brXHTMLTag)
}
r.cr(w)
case Emph:
if entering {
r.out(w, emTag)
} else {
r.out(w, emCloseTag)
}
case Strong:
if entering {
r.out(w, strongTag)
} else {
r.out(w, strongCloseTag)
}
case Del:
if entering {
r.out(w, delTag)
} else {
r.out(w, delCloseTag)
}
case HTMLSpan:
if r.Flags&SkipHTML != 0 {
break
}
r.out(w, node.Literal)
case Link:
// mark it but don't link it if it is not a safe link: no smartypants
dest := node.LinkData.Destination
if needSkipLink(r.Flags, dest) {
if entering {
r.out(w, ttTag)
} else {
r.out(w, ttCloseTag)
}
} else {
if entering {
dest = r.addAbsPrefix(dest)
var hrefBuf bytes.Buffer
hrefBuf.WriteString("href=\"")
escLink(&hrefBuf, dest)
hrefBuf.WriteByte('"')
attrs = append(attrs, hrefBuf.String())
if node.NoteID != 0 {
r.out(w, footnoteRef(r.FootnoteAnchorPrefix, node))
break
}
attrs = appendLinkAttrs(attrs, r.Flags, dest)
if len(node.LinkData.Title) > 0 {
var titleBuff bytes.Buffer
titleBuff.WriteString("title=\"")
escapeHTML(&titleBuff, node.LinkData.Title)
titleBuff.WriteByte('"')
attrs = append(attrs, titleBuff.String())
}
r.tag(w, aTag, attrs)
} else {
if node.NoteID != 0 {
break
}
r.out(w, aCloseTag)
}
}
case Image:
if r.Flags&SkipImages != 0 {
return SkipChildren
}
if entering {
dest := node.LinkData.Destination
dest = r.addAbsPrefix(dest)
if r.disableTags == 0 {
//if options.safe && potentiallyUnsafe(dest) {
//out(w, `<img src="" alt="`)
//} else {
r.out(w, []byte(`<img src="`))
escLink(w, dest)
r.out(w, []byte(`" alt="`))
//}
}
r.disableTags++
} else {
r.disableTags--
if r.disableTags == 0 {
if node.LinkData.Title != nil {
r.out(w, []byte(`" title="`))
escapeHTML(w, node.LinkData.Title)
}
r.out(w, []byte(`" />`))
}
}
case Code:
r.out(w, codeTag)
escapeAllHTML(w, node.Literal)
r.out(w, codeCloseTag)
case Document:
break
case Paragraph:
if skipParagraphTags(node) {
break
}
if entering {
// TODO: untangle this clusterfuck about when the newlines need
// to be added and when not.
if node.Prev != nil {
switch node.Prev.Type {
case HTMLBlock, List, Paragraph, Heading, CodeBlock, BlockQuote, HorizontalRule:
r.cr(w)
}
}
if node.Parent.Type == BlockQuote && node.Prev == nil {
r.cr(w)
}
r.out(w, pTag)
} else {
r.out(w, pCloseTag)
if !(node.Parent.Type == Item && node.Next == nil) {
r.cr(w)
}
}
case BlockQuote:
if entering {
r.cr(w)
r.out(w, blockquoteTag)
} else {
r.out(w, blockquoteCloseTag)
r.cr(w)
}
case HTMLBlock:
if r.Flags&SkipHTML != 0 {
break
}
r.cr(w)
r.out(w, node.Literal)
r.cr(w)
case Heading:
headingLevel := r.HTMLRendererParameters.HeadingLevelOffset + node.Level
openTag, closeTag := headingTagsFromLevel(headingLevel)
if entering {
if node.IsTitleblock {
attrs = append(attrs, `class="title"`)
}
if node.HeadingID != "" {
id := r.ensureUniqueHeadingID(node.HeadingID)
if r.HeadingIDPrefix != "" {
id = r.HeadingIDPrefix + id
}
if r.HeadingIDSuffix != "" {
id = id + r.HeadingIDSuffix
}
attrs = append(attrs, fmt.Sprintf(`id="%s"`, id))
}
r.cr(w)
r.tag(w, openTag, attrs)
} else {
r.out(w, closeTag)
if !(node.Parent.Type == Item && node.Next == nil) {
r.cr(w)
}
}
case HorizontalRule:
r.cr(w)
r.outHRTag(w)
r.cr(w)
case List:
openTag := ulTag
closeTag := ulCloseTag
if node.ListFlags&ListTypeOrdered != 0 {
openTag = olTag
closeTag = olCloseTag
}
if node.ListFlags&ListTypeDefinition != 0 {
openTag = dlTag
closeTag = dlCloseTag
}
if entering {
if node.IsFootnotesList {
r.out(w, footnotesDivBytes)
r.outHRTag(w)
r.cr(w)
}
r.cr(w)
if node.Parent.Type == Item && node.Parent.Parent.Tight {
r.cr(w)
}
r.tag(w, openTag[:len(openTag)-1], attrs)
r.cr(w)
} else {
r.out(w, closeTag)
//cr(w)
//if node.parent.Type != Item {
// cr(w)
//}
if node.Parent.Type == Item && node.Next != nil {
r.cr(w)
}
if node.Parent.Type == Document || node.Parent.Type == BlockQuote {
r.cr(w)
}
if node.IsFootnotesList {
r.out(w, footnotesCloseDivBytes)
}
}
case Item:
openTag := liTag
closeTag := liCloseTag
if node.ListFlags&ListTypeDefinition != 0 {
openTag = ddTag
closeTag = ddCloseTag
}
if node.ListFlags&ListTypeTerm != 0 {
openTag = dtTag
closeTag = dtCloseTag
}
if entering {
if itemOpenCR(node) {
r.cr(w)
}
if node.ListData.RefLink != nil {
slug := slugify(node.ListData.RefLink)
r.out(w, footnoteItem(r.FootnoteAnchorPrefix, slug))
break
}
r.out(w, openTag)
} else {
if node.ListData.RefLink != nil {
slug := slugify(node.ListData.RefLink)
if r.Flags&FootnoteReturnLinks != 0 {
r.out(w, footnoteReturnLink(r.FootnoteAnchorPrefix, r.FootnoteReturnLinkContents, slug))
}
}
r.out(w, closeTag)
r.cr(w)
}
case CodeBlock:
attrs = appendLanguageAttr(attrs, node.Info)
r.cr(w)
r.out(w, preTag)
r.tag(w, codeTag[:len(codeTag)-1], attrs)
escapeAllHTML(w, node.Literal)
r.out(w, codeCloseTag)
r.out(w, preCloseTag)
if node.Parent.Type != Item {
r.cr(w)
}
case Table:
if entering {
r.cr(w)
r.out(w, tableTag)
} else {
r.out(w, tableCloseTag)
r.cr(w)
}
case TableCell:
openTag := tdTag
closeTag := tdCloseTag
if node.IsHeader {
openTag = thTag
closeTag = thCloseTag
}
if entering {
align := cellAlignment(node.Align)
if align != "" {
attrs = append(attrs, fmt.Sprintf(`align="%s"`, align))
}
if node.Prev == nil {
r.cr(w)
}
r.tag(w, openTag, attrs)
} else {
r.out(w, closeTag)
r.cr(w)
}
case TableHead:
if entering {
r.cr(w)
r.out(w, theadTag)
} else {
r.out(w, theadCloseTag)
r.cr(w)
}
case TableBody:
if entering {
r.cr(w)
r.out(w, tbodyTag)
// XXX: this is to adhere to a rather silly test. Should fix test.
if node.FirstChild == nil {
r.cr(w)
}
} else {
r.out(w, tbodyCloseTag)
r.cr(w)
}
case TableRow:
if entering {
r.cr(w)
r.out(w, trTag)
} else {
r.out(w, trCloseTag)
r.cr(w)
}
default:
panic("Unknown node type " + node.Type.String())
}
return GoToNext
}
// RenderHeader writes HTML document preamble and TOC if requested.
func (r *HTMLRenderer) RenderHeader(w io.Writer, ast *Node) {
r.writeDocumentHeader(w)
if r.Flags&TOC != 0 {
r.writeTOC(w, ast)
}
}
// RenderFooter writes HTML document footer.
func (r *HTMLRenderer) RenderFooter(w io.Writer, ast *Node) {
if r.Flags&CompletePage == 0 {
return
}
io.WriteString(w, "\n</body>\n</html>\n")
}
func (r *HTMLRenderer) writeDocumentHeader(w io.Writer) {
if r.Flags&CompletePage == 0 {
return
}
ending := ""
if r.Flags&UseXHTML != 0 {
io.WriteString(w, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" ")
io.WriteString(w, "\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n")
io.WriteString(w, "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n")
ending = " /"
} else {
io.WriteString(w, "<!DOCTYPE html>\n")
io.WriteString(w, "<html>\n")
}
io.WriteString(w, "<head>\n")
io.WriteString(w, " <title>")
if r.Flags&Smartypants != 0 {
r.sr.Process(w, []byte(r.Title))
} else {
escapeHTML(w, []byte(r.Title))
}
io.WriteString(w, "</title>\n")
io.WriteString(w, " <meta name=\"GENERATOR\" content=\"Blackfriday Markdown Processor v")
io.WriteString(w, Version)
io.WriteString(w, "\"")
io.WriteString(w, ending)
io.WriteString(w, ">\n")
io.WriteString(w, " <meta charset=\"utf-8\"")
io.WriteString(w, ending)
io.WriteString(w, ">\n")
if r.CSS != "" {
io.WriteString(w, " <link rel=\"stylesheet\" type=\"text/css\" href=\"")
escapeHTML(w, []byte(r.CSS))
io.WriteString(w, "\"")
io.WriteString(w, ending)
io.WriteString(w, ">\n")
}
if r.Icon != "" {
io.WriteString(w, " <link rel=\"icon\" type=\"image/x-icon\" href=\"")
escapeHTML(w, []byte(r.Icon))
io.WriteString(w, "\"")
io.WriteString(w, ending)
io.WriteString(w, ">\n")
}
io.WriteString(w, "</head>\n")
io.WriteString(w, "<body>\n\n")
}
func (r *HTMLRenderer) writeTOC(w io.Writer, ast *Node) {
buf := bytes.Buffer{}
inHeading := false
tocLevel := 0
headingCount := 0
ast.Walk(func(node *Node, entering bool) WalkStatus {
if node.Type == Heading && !node.HeadingData.IsTitleblock {
inHeading = entering
if entering {
node.HeadingID = fmt.Sprintf("toc_%d", headingCount)
if node.Level == tocLevel {
buf.WriteString("</li>\n\n<li>")
} else if node.Level < tocLevel {
for node.Level < tocLevel {
tocLevel--
buf.WriteString("</li>\n</ul>")
}
buf.WriteString("</li>\n\n<li>")
} else {
for node.Level > tocLevel {
tocLevel++
buf.WriteString("\n<ul>\n<li>")
}
}
fmt.Fprintf(&buf, `<a href="#toc_%d">`, headingCount)
headingCount++
} else {
buf.WriteString("</a>")
}
return GoToNext
}
if inHeading {
return r.RenderNode(&buf, node, entering)
}
return GoToNext
})
for ; tocLevel > 0; tocLevel-- {
buf.WriteString("</li>\n</ul>")
}
if buf.Len() > 0 {
io.WriteString(w, "<nav>\n")
w.Write(buf.Bytes())
io.WriteString(w, "\n\n</nav>\n")
}
r.lastOutputLen = buf.Len()
}