html.go (view raw)
1//
2// Blackfriday Markdown Processor
3// Available at http://github.com/russross/blackfriday
4//
5// Copyright © 2011 Russ Ross <russ@russross.com>.
6// Distributed under the Simplified BSD License.
7// See README.md for details.
8//
9
10//
11//
12// HTML rendering backend
13//
14//
15
16package blackfriday
17
18import (
19 "bytes"
20 "fmt"
21 "io"
22 "regexp"
23 "strings"
24)
25
26// HTMLFlags control optional behavior of HTML renderer.
27type HTMLFlags int
28
29// HTML renderer configuration options.
30const (
31 HTMLFlagsNone HTMLFlags = 0
32 SkipHTML HTMLFlags = 1 << iota // Skip preformatted HTML blocks
33 SkipStyle // Skip embedded <style> elements
34 SkipImages // Skip embedded images
35 SkipLinks // Skip all links
36 Safelink // Only link to trusted protocols
37 NofollowLinks // Only link with rel="nofollow"
38 NoreferrerLinks // Only link with rel="noreferrer"
39 HrefTargetBlank // Add a blank target
40 CompletePage // Generate a complete HTML page
41 UseXHTML // Generate XHTML output instead of HTML
42 FootnoteReturnLinks // Generate a link at the end of a footnote to return to the source
43 Smartypants // Enable smart punctuation substitutions
44 SmartypantsFractions // Enable smart fractions (with Smartypants)
45 SmartypantsDashes // Enable smart dashes (with Smartypants)
46 SmartypantsLatexDashes // Enable LaTeX-style dashes (with Smartypants)
47 SmartypantsAngledQuotes // Enable angled double quotes (with Smartypants) for double quotes rendering
48
49 TagName = "[A-Za-z][A-Za-z0-9-]*"
50 AttributeName = "[a-zA-Z_:][a-zA-Z0-9:._-]*"
51 UnquotedValue = "[^\"'=<>`\\x00-\\x20]+"
52 SingleQuotedValue = "'[^']*'"
53 DoubleQuotedValue = "\"[^\"]*\""
54 AttributeValue = "(?:" + UnquotedValue + "|" + SingleQuotedValue + "|" + DoubleQuotedValue + ")"
55 AttributeValueSpec = "(?:" + "\\s*=" + "\\s*" + AttributeValue + ")"
56 Attribute = "(?:" + "\\s+" + AttributeName + AttributeValueSpec + "?)"
57 OpenTag = "<" + TagName + Attribute + "*" + "\\s*/?>"
58 CloseTag = "</" + TagName + "\\s*[>]"
59 HTMLComment = "<!---->|<!--(?:-?[^>-])(?:-?[^-])*-->"
60 ProcessingInstruction = "[<][?].*?[?][>]"
61 Declaration = "<![A-Z]+" + "\\s+[^>]*>"
62 CDATA = "<!\\[CDATA\\[[\\s\\S]*?\\]\\]>"
63 HTMLTag = "(?:" + OpenTag + "|" + CloseTag + "|" + HTMLComment + "|" +
64 ProcessingInstruction + "|" + Declaration + "|" + CDATA + ")"
65)
66
67var (
68 htmlTagRe = regexp.MustCompile("(?i)^" + HTMLTag)
69)
70
71// HTMLRendererParameters is a collection of supplementary parameters tweaking
72// the behavior of various parts of HTML renderer.
73type HTMLRendererParameters struct {
74 // Prepend this text to each relative URL.
75 AbsolutePrefix string
76 // Add this text to each footnote anchor, to ensure uniqueness.
77 FootnoteAnchorPrefix string
78 // Show this text inside the <a> tag for a footnote return link, if the
79 // HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
80 // <sup>[return]</sup> is used.
81 FootnoteReturnLinkContents string
82 // If set, add this text to the front of each Header ID, to ensure
83 // uniqueness.
84 HeaderIDPrefix string
85 // If set, add this text to the back of each Header ID, to ensure uniqueness.
86 HeaderIDSuffix string
87
88 Title string // Document title (used if CompletePage is set)
89 CSS string // Optional CSS file URL (used if CompletePage is set)
90 Icon string // Optional icon file URL (used if CompletePage is set)
91
92 Flags HTMLFlags // Flags allow customizing this renderer's behavior
93 Extensions Extensions // Extensions give Smartypants and HTML renderer access to Blackfriday's global extensions
94}
95
96// HTMLRenderer is a type that implements the Renderer interface for HTML output.
97//
98// Do not create this directly, instead use the NewHTMLRenderer function.
99type HTMLRenderer struct {
100 HTMLRendererParameters
101
102 closeTag string // how to end singleton tags: either " />" or ">"
103
104 // Track header IDs to prevent ID collision in a single generation.
105 headerIDs map[string]int
106
107 lastOutputLen int
108 disableTags int
109
110 sr *SPRenderer
111}
112
113const (
114 xhtmlClose = " />"
115 htmlClose = ">"
116)
117
118// NewHTMLRenderer creates and configures an HTMLRenderer object, which
119// satisfies the Renderer interface.
120func NewHTMLRenderer(params HTMLRendererParameters) *HTMLRenderer {
121 // configure the rendering engine
122 closeTag := htmlClose
123 if params.Flags&UseXHTML != 0 {
124 closeTag = xhtmlClose
125 }
126
127 if params.FootnoteReturnLinkContents == "" {
128 params.FootnoteReturnLinkContents = `<sup>[return]</sup>`
129 }
130
131 return &HTMLRenderer{
132 HTMLRendererParameters: params,
133
134 closeTag: closeTag,
135 headerIDs: make(map[string]int),
136
137 sr: NewSmartypantsRenderer(params.Flags),
138 }
139}
140
141func isHTMLTag(tag []byte, tagname string) bool {
142 found, _ := findHTMLTagPos(tag, tagname)
143 return found
144}
145
146// Look for a character, but ignore it when it's in any kind of quotes, it
147// might be JavaScript
148func skipUntilCharIgnoreQuotes(html []byte, start int, char byte) int {
149 inSingleQuote := false
150 inDoubleQuote := false
151 inGraveQuote := false
152 i := start
153 for i < len(html) {
154 switch {
155 case html[i] == char && !inSingleQuote && !inDoubleQuote && !inGraveQuote:
156 return i
157 case html[i] == '\'':
158 inSingleQuote = !inSingleQuote
159 case html[i] == '"':
160 inDoubleQuote = !inDoubleQuote
161 case html[i] == '`':
162 inGraveQuote = !inGraveQuote
163 }
164 i++
165 }
166 return start
167}
168
169func findHTMLTagPos(tag []byte, tagname string) (bool, int) {
170 i := 0
171 if i < len(tag) && tag[0] != '<' {
172 return false, -1
173 }
174 i++
175 i = skipSpace(tag, i)
176
177 if i < len(tag) && tag[i] == '/' {
178 i++
179 }
180
181 i = skipSpace(tag, i)
182 j := 0
183 for ; i < len(tag); i, j = i+1, j+1 {
184 if j >= len(tagname) {
185 break
186 }
187
188 if strings.ToLower(string(tag[i]))[0] != tagname[j] {
189 return false, -1
190 }
191 }
192
193 if i == len(tag) {
194 return false, -1
195 }
196
197 rightAngle := skipUntilCharIgnoreQuotes(tag, i, '>')
198 if rightAngle >= i {
199 return true, rightAngle
200 }
201
202 return false, -1
203}
204
205func skipSpace(tag []byte, i int) int {
206 for i < len(tag) && isspace(tag[i]) {
207 i++
208 }
209 return i
210}
211
212func isRelativeLink(link []byte) (yes bool) {
213 // a tag begin with '#'
214 if link[0] == '#' {
215 return true
216 }
217
218 // link begin with '/' but not '//', the second maybe a protocol relative link
219 if len(link) >= 2 && link[0] == '/' && link[1] != '/' {
220 return true
221 }
222
223 // only the root '/'
224 if len(link) == 1 && link[0] == '/' {
225 return true
226 }
227
228 // current directory : begin with "./"
229 if bytes.HasPrefix(link, []byte("./")) {
230 return true
231 }
232
233 // parent directory : begin with "../"
234 if bytes.HasPrefix(link, []byte("../")) {
235 return true
236 }
237
238 return false
239}
240
241func (r *HTMLRenderer) ensureUniqueHeaderID(id string) string {
242 for count, found := r.headerIDs[id]; found; count, found = r.headerIDs[id] {
243 tmp := fmt.Sprintf("%s-%d", id, count+1)
244
245 if _, tmpFound := r.headerIDs[tmp]; !tmpFound {
246 r.headerIDs[id] = count + 1
247 id = tmp
248 } else {
249 id = id + "-1"
250 }
251 }
252
253 if _, found := r.headerIDs[id]; !found {
254 r.headerIDs[id] = 0
255 }
256
257 return id
258}
259
260func (r *HTMLRenderer) addAbsPrefix(link []byte) []byte {
261 if r.AbsolutePrefix != "" && isRelativeLink(link) && link[0] != '.' {
262 newDest := r.AbsolutePrefix
263 if link[0] != '/' {
264 newDest += "/"
265 }
266 newDest += string(link)
267 return []byte(newDest)
268 }
269 return link
270}
271
272func appendLinkAttrs(attrs []string, flags HTMLFlags, link []byte) []string {
273 if isRelativeLink(link) {
274 return attrs
275 }
276 val := []string{}
277 if flags&NofollowLinks != 0 {
278 val = append(val, "nofollow")
279 }
280 if flags&NoreferrerLinks != 0 {
281 val = append(val, "noreferrer")
282 }
283 if flags&HrefTargetBlank != 0 {
284 attrs = append(attrs, "target=\"_blank\"")
285 }
286 if len(val) == 0 {
287 return attrs
288 }
289 attr := fmt.Sprintf("rel=%q", strings.Join(val, " "))
290 return append(attrs, attr)
291}
292
293func isMailto(link []byte) bool {
294 return bytes.HasPrefix(link, []byte("mailto:"))
295}
296
297func needSkipLink(flags HTMLFlags, dest []byte) bool {
298 if flags&SkipLinks != 0 {
299 return true
300 }
301 return flags&Safelink != 0 && !isSafeLink(dest) && !isMailto(dest)
302}
303
304func isSmartypantable(node *Node) bool {
305 pt := node.Parent.Type
306 return pt != Link && pt != CodeBlock && pt != Code
307}
308
309func appendLanguageAttr(attrs []string, info []byte) []string {
310 infoWords := bytes.Split(info, []byte("\t "))
311 if len(infoWords) > 0 && len(infoWords[0]) > 0 {
312 attrs = append(attrs, fmt.Sprintf("class=\"language-%s\"", infoWords[0]))
313 }
314 return attrs
315}
316
317var (
318 gtBytes = []byte{'>'}
319 spaceBytes = []byte{' '}
320)
321
322func (r *HTMLRenderer) tag(w io.Writer, name []byte, attrs []string) {
323 w.Write(name)
324 if len(attrs) > 0 {
325 w.Write(spaceBytes)
326 w.Write([]byte(strings.Join(attrs, " ")))
327 }
328 w.Write(gtBytes)
329 r.lastOutputLen = 1
330}
331
332func footnoteRef(prefix string, node *Node) []byte {
333 urlFrag := prefix + string(slugify(node.Destination))
334 anchor := fmt.Sprintf(`<a rel="footnote" href="#fn:%s">%d</a>`, urlFrag, node.NoteID)
335 return []byte(fmt.Sprintf(`<sup class="footnote-ref" id="fnref:%s">%s</sup>`, urlFrag, anchor))
336}
337
338func footnoteItem(prefix string, slug []byte) []byte {
339 return []byte(fmt.Sprintf(`<li id="fn:%s%s">`, prefix, slug))
340}
341
342func footnoteReturnLink(prefix, returnLink string, slug []byte) []byte {
343 const format = ` <a class="footnote-return" href="#fnref:%s%s">%s</a>`
344 return []byte(fmt.Sprintf(format, prefix, slug, returnLink))
345}
346
347func itemOpenCR(node *Node) bool {
348 if node.Prev == nil {
349 return false
350 }
351 ld := node.Parent.ListData
352 return !ld.Tight && ld.ListFlags&ListTypeDefinition == 0
353}
354
355func skipParagraphTags(node *Node) bool {
356 grandparent := node.Parent.Parent
357 if grandparent == nil || grandparent.Type != List {
358 return false
359 }
360 tightOrTerm := grandparent.Tight || node.Parent.ListFlags&ListTypeTerm != 0
361 return grandparent.Type == List && tightOrTerm
362}
363
364func cellAlignment(align CellAlignFlags) string {
365 switch align {
366 case TableAlignmentLeft:
367 return "left"
368 case TableAlignmentRight:
369 return "right"
370 case TableAlignmentCenter:
371 return "center"
372 default:
373 return ""
374 }
375}
376
377func (r *HTMLRenderer) out(w io.Writer, text []byte) {
378 if r.disableTags > 0 {
379 w.Write(htmlTagRe.ReplaceAll(text, []byte{}))
380 } else {
381 w.Write(text)
382 }
383 r.lastOutputLen = len(text)
384}
385
386func (r *HTMLRenderer) cr(w io.Writer) {
387 if r.lastOutputLen > 0 {
388 r.out(w, []byte{'\n'})
389 }
390}
391
392var (
393 brTag = []byte("<br>")
394 brXHTMLTag = []byte("<br />")
395 emTag = []byte("<em>")
396 emCloseTag = []byte("</em>")
397 strongTag = []byte("<strong>")
398 strongCloseTag = []byte("</strong>")
399 delTag = []byte("<del>")
400 delCloseTag = []byte("</del>")
401 ttTag = []byte("<tt>")
402 ttCloseTag = []byte("</tt>")
403 aTag = []byte("<a")
404 aCloseTag = []byte("</a>")
405 preTag = []byte("<pre>")
406 preCloseTag = []byte("</pre>")
407 codeTag = []byte("<code>")
408 codeCloseTag = []byte("</code>")
409 pTag = []byte("<p>")
410 pCloseTag = []byte("</p>")
411 blockquoteTag = []byte("<blockquote>")
412 blockquoteCloseTag = []byte("</blockquote>")
413 hrTag = []byte("<hr>")
414 hrXHTMLTag = []byte("<hr />")
415 ulTag = []byte("<ul>")
416 ulCloseTag = []byte("</ul>")
417 olTag = []byte("<ol>")
418 olCloseTag = []byte("</ol>")
419 dlTag = []byte("<dl>")
420 dlCloseTag = []byte("</dl>")
421 liTag = []byte("<li>")
422 liCloseTag = []byte("</li>")
423 ddTag = []byte("<dd>")
424 ddCloseTag = []byte("</dd>")
425 dtTag = []byte("<dt>")
426 dtCloseTag = []byte("</dt>")
427 tableTag = []byte("<table>")
428 tableCloseTag = []byte("</table>")
429 tdTag = []byte("<td")
430 tdCloseTag = []byte("</td>")
431 thTag = []byte("<th")
432 thCloseTag = []byte("</th>")
433 theadTag = []byte("<thead>")
434 theadCloseTag = []byte("</thead>")
435 tbodyTag = []byte("<tbody>")
436 tbodyCloseTag = []byte("</tbody>")
437 trTag = []byte("<tr>")
438 trCloseTag = []byte("</tr>")
439 h1Tag = []byte("<h1")
440 h1CloseTag = []byte("</h1>")
441 h2Tag = []byte("<h2")
442 h2CloseTag = []byte("</h2>")
443 h3Tag = []byte("<h3")
444 h3CloseTag = []byte("</h3>")
445 h4Tag = []byte("<h4")
446 h4CloseTag = []byte("</h4>")
447 h5Tag = []byte("<h5")
448 h5CloseTag = []byte("</h5>")
449 h6Tag = []byte("<h6")
450 h6CloseTag = []byte("</h6>")
451
452 footnotesDivBytes = []byte("\n<div class=\"footnotes\">\n\n")
453 footnotesCloseDivBytes = []byte("\n</div>\n")
454)
455
456func headerTagsFromLevel(level int) ([]byte, []byte) {
457 switch level {
458 case 1:
459 return h1Tag, h1CloseTag
460 case 2:
461 return h2Tag, h2CloseTag
462 case 3:
463 return h3Tag, h3CloseTag
464 case 4:
465 return h4Tag, h4CloseTag
466 case 5:
467 return h5Tag, h5CloseTag
468 default:
469 return h6Tag, h6CloseTag
470 }
471}
472
473func (r *HTMLRenderer) outHRTag(w io.Writer) {
474 if r.Flags&UseXHTML == 0 {
475 r.out(w, hrTag)
476 } else {
477 r.out(w, hrXHTMLTag)
478 }
479}
480
481// RenderNode is a default renderer of a single node of a syntax tree. For
482// block nodes it will be called twice: first time with entering=true, second
483// time with entering=false, so that it could know when it's working on an open
484// tag and when on close. It writes the result to w.
485//
486// The return value is a way to tell the calling walker to adjust its walk
487// pattern: e.g. it can terminate the traversal by returning Terminate. Or it
488// can ask the walker to skip a subtree of this node by returning SkipChildren.
489// The typical behavior is to return GoToNext, which asks for the usual
490// traversal to the next node.
491func (r *HTMLRenderer) RenderNode(w io.Writer, node *Node, entering bool) WalkStatus {
492 attrs := []string{}
493 switch node.Type {
494 case Text:
495 if r.Flags&Smartypants != 0 {
496 var tmp bytes.Buffer
497 escapeHTML(&tmp, node.Literal)
498 r.sr.Process(w, tmp.Bytes())
499 } else {
500 if node.Parent.Type == Link {
501 escLink(w, node.Literal)
502 } else {
503 escapeHTML(w, node.Literal)
504 }
505 }
506 case Softbreak:
507 r.out(w, []byte{'\n'})
508 // TODO: make it configurable via out(renderer.softbreak)
509 case Hardbreak:
510 if r.Flags&UseXHTML == 0 {
511 r.out(w, brTag)
512 } else {
513 r.out(w, brXHTMLTag)
514 }
515 r.cr(w)
516 case Emph:
517 if entering {
518 r.out(w, emTag)
519 } else {
520 r.out(w, emCloseTag)
521 }
522 case Strong:
523 if entering {
524 r.out(w, strongTag)
525 } else {
526 r.out(w, strongCloseTag)
527 }
528 case Del:
529 if entering {
530 r.out(w, delTag)
531 } else {
532 r.out(w, delCloseTag)
533 }
534 case HTMLSpan:
535 if r.Flags&SkipHTML != 0 {
536 break
537 }
538 if r.Flags&SkipStyle != 0 && isHTMLTag(node.Literal, "style") {
539 break
540 }
541 //if options.safe {
542 // out(w, "<!-- raw HTML omitted -->")
543 //} else {
544 r.out(w, node.Literal)
545 //}
546 case Link:
547 // mark it but don't link it if it is not a safe link: no smartypants
548 dest := node.LinkData.Destination
549 if needSkipLink(r.Flags, dest) {
550 if entering {
551 r.out(w, ttTag)
552 } else {
553 r.out(w, ttCloseTag)
554 }
555 } else {
556 if entering {
557 dest = r.addAbsPrefix(dest)
558 var hrefBuff bytes.Buffer
559 hrefBuff.WriteString("href=\"")
560 escLink(&hrefBuff, dest)
561 hrefBuff.WriteByte('"')
562 attrs = append(attrs, hrefBuff.String())
563 if node.NoteID != 0 {
564 r.out(w, footnoteRef(r.FootnoteAnchorPrefix, node))
565 break
566 }
567 attrs = appendLinkAttrs(attrs, r.Flags, dest)
568 if len(node.LinkData.Title) > 0 {
569 var titleBuff bytes.Buffer
570 titleBuff.WriteString("title=\"")
571 escapeHTML(&titleBuff, node.LinkData.Title)
572 titleBuff.WriteByte('"')
573 attrs = append(attrs, titleBuff.String())
574 }
575 r.tag(w, aTag, attrs)
576 } else {
577 if node.NoteID != 0 {
578 break
579 }
580 r.out(w, aCloseTag)
581 }
582 }
583 case Image:
584 if r.Flags&SkipImages != 0 {
585 return SkipChildren
586 }
587 if entering {
588 dest := node.LinkData.Destination
589 dest = r.addAbsPrefix(dest)
590 if r.disableTags == 0 {
591 //if options.safe && potentiallyUnsafe(dest) {
592 //out(w, `<img src="" alt="`)
593 //} else {
594 r.out(w, []byte(`<img src="`))
595 escLink(w, dest)
596 r.out(w, []byte(`" alt="`))
597 //}
598 }
599 r.disableTags++
600 } else {
601 r.disableTags--
602 if r.disableTags == 0 {
603 if node.LinkData.Title != nil {
604 r.out(w, []byte(`" title="`))
605 escapeHTML(w, node.LinkData.Title)
606 }
607 r.out(w, []byte(`" />`))
608 }
609 }
610 case Code:
611 r.out(w, codeTag)
612 escapeHTML(w, node.Literal)
613 r.out(w, codeCloseTag)
614 case Document:
615 break
616 case Paragraph:
617 if skipParagraphTags(node) {
618 break
619 }
620 if entering {
621 // TODO: untangle this clusterfuck about when the newlines need
622 // to be added and when not.
623 if node.Prev != nil {
624 switch node.Prev.Type {
625 case HTMLBlock, List, Paragraph, Header, CodeBlock, BlockQuote, HorizontalRule:
626 r.cr(w)
627 }
628 }
629 if node.Parent.Type == BlockQuote && node.Prev == nil {
630 r.cr(w)
631 }
632 r.out(w, pTag)
633 } else {
634 r.out(w, pCloseTag)
635 if !(node.Parent.Type == Item && node.Next == nil) {
636 r.cr(w)
637 }
638 }
639 case BlockQuote:
640 if entering {
641 r.cr(w)
642 r.out(w, blockquoteTag)
643 } else {
644 r.out(w, blockquoteCloseTag)
645 r.cr(w)
646 }
647 case HTMLBlock:
648 if r.Flags&SkipHTML != 0 {
649 break
650 }
651 r.cr(w)
652 r.out(w, node.Literal)
653 r.cr(w)
654 case Header:
655 openTag, closeTag := headerTagsFromLevel(node.Level)
656 if entering {
657 if node.IsTitleblock {
658 attrs = append(attrs, `class="title"`)
659 }
660 if node.HeaderID != "" {
661 id := r.ensureUniqueHeaderID(node.HeaderID)
662 if r.HeaderIDPrefix != "" {
663 id = r.HeaderIDPrefix + id
664 }
665 if r.HeaderIDSuffix != "" {
666 id = id + r.HeaderIDSuffix
667 }
668 attrs = append(attrs, fmt.Sprintf(`id="%s"`, id))
669 }
670 r.cr(w)
671 r.tag(w, openTag, attrs)
672 } else {
673 r.out(w, closeTag)
674 if !(node.Parent.Type == Item && node.Next == nil) {
675 r.cr(w)
676 }
677 }
678 case HorizontalRule:
679 r.cr(w)
680 r.outHRTag(w)
681 r.cr(w)
682 case List:
683 openTag := ulTag
684 closeTag := ulCloseTag
685 if node.ListFlags&ListTypeOrdered != 0 {
686 openTag = olTag
687 closeTag = olCloseTag
688 }
689 if node.ListFlags&ListTypeDefinition != 0 {
690 openTag = dlTag
691 closeTag = dlCloseTag
692 }
693 if entering {
694 if node.IsFootnotesList {
695 r.out(w, footnotesDivBytes)
696 r.outHRTag(w)
697 r.cr(w)
698 }
699 r.cr(w)
700 if node.Parent.Type == Item && node.Parent.Parent.Tight {
701 r.cr(w)
702 }
703 r.tag(w, openTag[:len(openTag)-1], attrs)
704 r.cr(w)
705 } else {
706 r.out(w, closeTag)
707 //cr(w)
708 //if node.parent.Type != Item {
709 // cr(w)
710 //}
711 if node.Parent.Type == Item && node.Next != nil {
712 r.cr(w)
713 }
714 if node.Parent.Type == Document || node.Parent.Type == BlockQuote {
715 r.cr(w)
716 }
717 if node.IsFootnotesList {
718 r.out(w, footnotesCloseDivBytes)
719 }
720 }
721 case Item:
722 openTag := liTag
723 closeTag := liCloseTag
724 if node.ListFlags&ListTypeDefinition != 0 {
725 openTag = ddTag
726 closeTag = ddCloseTag
727 }
728 if node.ListFlags&ListTypeTerm != 0 {
729 openTag = dtTag
730 closeTag = dtCloseTag
731 }
732 if entering {
733 if itemOpenCR(node) {
734 r.cr(w)
735 }
736 if node.ListData.RefLink != nil {
737 slug := slugify(node.ListData.RefLink)
738 r.out(w, footnoteItem(r.FootnoteAnchorPrefix, slug))
739 break
740 }
741 r.out(w, openTag)
742 } else {
743 if node.ListData.RefLink != nil {
744 slug := slugify(node.ListData.RefLink)
745 if r.Flags&FootnoteReturnLinks != 0 {
746 r.out(w, footnoteReturnLink(r.FootnoteAnchorPrefix, r.FootnoteReturnLinkContents, slug))
747 }
748 }
749 r.out(w, closeTag)
750 r.cr(w)
751 }
752 case CodeBlock:
753 attrs = appendLanguageAttr(attrs, node.Info)
754 r.cr(w)
755 r.out(w, preTag)
756 r.tag(w, codeTag[:len(codeTag)-1], attrs)
757 escapeHTML(w, node.Literal)
758 r.out(w, codeCloseTag)
759 r.out(w, preCloseTag)
760 if node.Parent.Type != Item {
761 r.cr(w)
762 }
763 case Table:
764 if entering {
765 r.cr(w)
766 r.out(w, tableTag)
767 } else {
768 r.out(w, tableCloseTag)
769 r.cr(w)
770 }
771 case TableCell:
772 openTag := tdTag
773 closeTag := tdCloseTag
774 if node.IsHeader {
775 openTag = thTag
776 closeTag = thCloseTag
777 }
778 if entering {
779 align := cellAlignment(node.Align)
780 if align != "" {
781 attrs = append(attrs, fmt.Sprintf(`align="%s"`, align))
782 }
783 if node.Prev == nil {
784 r.cr(w)
785 }
786 r.tag(w, openTag, attrs)
787 } else {
788 r.out(w, closeTag)
789 r.cr(w)
790 }
791 case TableHead:
792 if entering {
793 r.cr(w)
794 r.out(w, theadTag)
795 } else {
796 r.out(w, theadCloseTag)
797 r.cr(w)
798 }
799 case TableBody:
800 if entering {
801 r.cr(w)
802 r.out(w, tbodyTag)
803 // XXX: this is to adhere to a rather silly test. Should fix test.
804 if node.FirstChild == nil {
805 r.cr(w)
806 }
807 } else {
808 r.out(w, tbodyCloseTag)
809 r.cr(w)
810 }
811 case TableRow:
812 if entering {
813 r.cr(w)
814 r.out(w, trTag)
815 } else {
816 r.out(w, trCloseTag)
817 r.cr(w)
818 }
819 default:
820 panic("Unknown node type " + node.Type.String())
821 }
822 return GoToNext
823}
824
825func (r *HTMLRenderer) writeDocumentHeader(w *bytes.Buffer) {
826 if r.Flags&CompletePage == 0 {
827 return
828 }
829 ending := ""
830 if r.Flags&UseXHTML != 0 {
831 w.WriteString("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" ")
832 w.WriteString("\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n")
833 w.WriteString("<html xmlns=\"http://www.w3.org/1999/xhtml\">\n")
834 ending = " /"
835 } else {
836 w.WriteString("<!DOCTYPE html>\n")
837 w.WriteString("<html>\n")
838 }
839 w.WriteString("<head>\n")
840 w.WriteString(" <title>")
841 if r.Flags&Smartypants != 0 {
842 r.sr.Process(w, []byte(r.Title))
843 } else {
844 escapeHTML(w, []byte(r.Title))
845 }
846 w.WriteString("</title>\n")
847 w.WriteString(" <meta name=\"GENERATOR\" content=\"Blackfriday Markdown Processor v")
848 w.WriteString(Version)
849 w.WriteString("\"")
850 w.WriteString(ending)
851 w.WriteString(">\n")
852 w.WriteString(" <meta charset=\"utf-8\"")
853 w.WriteString(ending)
854 w.WriteString(">\n")
855 if r.CSS != "" {
856 w.WriteString(" <link rel=\"stylesheet\" type=\"text/css\" href=\"")
857 escapeHTML(w, []byte(r.CSS))
858 w.WriteString("\"")
859 w.WriteString(ending)
860 w.WriteString(">\n")
861 }
862 if r.Icon != "" {
863 w.WriteString(" <link rel=\"icon\" type=\"image/x-icon\" href=\"")
864 escapeHTML(w, []byte(r.Icon))
865 w.WriteString("\"")
866 w.WriteString(ending)
867 w.WriteString(">\n")
868 }
869 w.WriteString("</head>\n")
870 w.WriteString("<body>\n\n")
871}
872
873func (r *HTMLRenderer) writeTOC(w *bytes.Buffer, ast *Node) {
874 buf := bytes.Buffer{}
875
876 inHeader := false
877 tocLevel := 0
878 headerCount := 0
879
880 ast.Walk(func(node *Node, entering bool) WalkStatus {
881 if node.Type == Header && !node.HeaderData.IsTitleblock {
882 inHeader = entering
883 if entering {
884 node.HeaderID = fmt.Sprintf("toc_%d", headerCount)
885 if node.Level == tocLevel {
886 buf.WriteString("</li>\n\n<li>")
887 } else if node.Level < tocLevel {
888 for node.Level < tocLevel {
889 tocLevel--
890 buf.WriteString("</li>\n</ul>")
891 }
892 buf.WriteString("</li>\n\n<li>")
893 } else {
894 for node.Level > tocLevel {
895 tocLevel++
896 buf.WriteString("\n<ul>\n<li>")
897 }
898 }
899
900 fmt.Fprintf(&buf, `<a href="#toc_%d">`, headerCount)
901 headerCount++
902 } else {
903 buf.WriteString("</a>")
904 }
905 return GoToNext
906 }
907
908 if inHeader {
909 return r.RenderNode(&buf, node, entering)
910 }
911
912 return GoToNext
913 })
914
915 for ; tocLevel > 0; tocLevel-- {
916 buf.WriteString("</li>\n</ul>")
917 }
918
919 if buf.Len() > 0 {
920 w.WriteString("<nav>\n")
921 w.Write(buf.Bytes())
922 w.WriteString("\n\n</nav>\n")
923 }
924 r.lastOutputLen = buf.Len()
925}
926
927func (r *HTMLRenderer) writeDocumentFooter(w *bytes.Buffer) {
928 if r.Flags&CompletePage == 0 {
929 return
930 }
931 w.WriteString("\n</body>\n</html>\n")
932}
933
934// Render walks the specified syntax (sub)tree and returns a HTML document.
935func (r *HTMLRenderer) Render(ast *Node) []byte {
936 //println("render_Blackfriday")
937 //dump(ast)
938 var buff bytes.Buffer
939 r.writeDocumentHeader(&buff)
940 if r.Extensions&TOC != 0 || r.Extensions&OmitContents != 0 {
941 r.writeTOC(&buff, ast)
942 if r.Extensions&OmitContents != 0 {
943 return buff.Bytes()
944 }
945 }
946 ast.Walk(func(node *Node, entering bool) WalkStatus {
947 return r.RenderNode(&buff, node, entering)
948 })
949 r.writeDocumentFooter(&buff)
950 return buff.Bytes()
951}