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gitea/modules/markup/markdown/markdown.go

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6.2 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2018 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package markdown
import (
"bytes"
"io"
"strings"
"code.gitea.io/gitea/modules/markup"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
"github.com/russross/blackfriday/v2"
)
// Renderer is a extended version of underlying render object.
type Renderer struct {
blackfriday.Renderer
URLPrefix string
IsWiki bool
}
var byteMailto = []byte("mailto:")
var htmlEscaper = [256][]byte{
'&': []byte("&"),
'<': []byte("&lt;"),
'>': []byte("&gt;"),
'"': []byte("&quot;"),
}
func escapeHTML(w io.Writer, s []byte) {
var start, end int
for end < len(s) {
escSeq := htmlEscaper[s[end]]
if escSeq != nil {
_, _ = w.Write(s[start:end])
_, _ = w.Write(escSeq)
start = end + 1
}
end++
}
if start < len(s) && end <= len(s) {
_, _ = w.Write(s[start:end])
}
}
// 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 *Renderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
switch node.Type {
case blackfriday.Image:
prefix := r.URLPrefix
if r.IsWiki {
prefix = util.URLJoin(prefix, "wiki", "raw")
}
prefix = strings.Replace(prefix, "/src/", "/media/", 1)
link := node.LinkData.Destination
if len(link) > 0 && !markup.IsLink(link) {
lnk := string(link)
lnk = util.URLJoin(prefix, lnk)
lnk = strings.Replace(lnk, " ", "+", -1)
link = []byte(lnk)
}
node.LinkData.Destination = link
// Render link around image only if parent is not link already
if node.Parent != nil && node.Parent.Type != blackfriday.Link {
if entering {
_, _ = w.Write([]byte(`<a href="`))
escapeHTML(w, link)
_, _ = w.Write([]byte(`">`))
return r.Renderer.RenderNode(w, node, entering)
}
s := r.Renderer.RenderNode(w, node, entering)
_, _ = w.Write([]byte(`</a>`))
return s
}
return r.Renderer.RenderNode(w, node, entering)
case blackfriday.Link:
// special case: this is not a link, a hash link or a mailto:, so it's a
// relative URL
link := node.LinkData.Destination
if len(link) > 0 && !markup.IsLink(link) &&
link[0] != '#' && !bytes.HasPrefix(link, byteMailto) &&
node.LinkData.Footnote == nil {
lnk := string(link)
if r.IsWiki {
lnk = util.URLJoin("wiki", lnk)
}
link = []byte(util.URLJoin(r.URLPrefix, lnk))
}
node.LinkData.Destination = link
return r.Renderer.RenderNode(w, node, entering)
case blackfriday.Text:
isListItem := false
for n := node.Parent; n != nil; n = n.Parent {
if n.Type == blackfriday.Item {
isListItem = true
break
}
}
if isListItem {
text := node.Literal
switch {
case bytes.HasPrefix(text, []byte("[ ] ")):
_, _ = w.Write([]byte(`<span class="ui fitted disabled checkbox"><input type="checkbox" disabled="disabled" /><label /></span>`))
text = text[3:]
case bytes.HasPrefix(text, []byte("[x] ")):
_, _ = w.Write([]byte(`<span class="ui checked fitted disabled checkbox"><input type="checkbox" checked="" disabled="disabled" /><label /></span>`))
text = text[3:]
}
node.Literal = text
}
}
return r.Renderer.RenderNode(w, node, entering)
}
const (
blackfridayExtensions = 0 |
blackfriday.NoIntraEmphasis |
blackfriday.Tables |
blackfriday.FencedCode |
blackfriday.Strikethrough |
blackfriday.NoEmptyLineBeforeBlock |
blackfriday.DefinitionLists |
blackfriday.Footnotes |
blackfriday.HeadingIDs |
blackfriday.AutoHeadingIDs
blackfridayHTMLFlags = 0 |
blackfriday.Smartypants
)
// RenderRaw renders Markdown to HTML without handling special links.
func RenderRaw(body []byte, urlPrefix string, wikiMarkdown bool) []byte {
renderer := &Renderer{
Renderer: blackfriday.NewHTMLRenderer(blackfriday.HTMLRendererParameters{
Flags: blackfridayHTMLFlags,
}),
URLPrefix: urlPrefix,
IsWiki: wikiMarkdown,
}
exts := blackfridayExtensions
if setting.Markdown.EnableHardLineBreak {
exts |= blackfriday.HardLineBreak
}
// Need to normalize EOL to UNIX LF to have consistent results in rendering
body = blackfriday.Run(util.NormalizeEOL(body), blackfriday.WithRenderer(renderer), blackfriday.WithExtensions(exts))
return markup.SanitizeBytes(body)
}
var (
// MarkupName describes markup's name
MarkupName = "markdown"
)
func init() {
markup.RegisterParser(Parser{})
}
// Parser implements markup.Parser
type Parser struct {
}
// Name implements markup.Parser
func (Parser) Name() string {
return MarkupName
}
// Extensions implements markup.Parser
func (Parser) Extensions() []string {
return setting.Markdown.FileExtensions
}
// Render implements markup.Parser
func (Parser) Render(rawBytes []byte, urlPrefix string, metas map[string]string, isWiki bool) []byte {
return RenderRaw(rawBytes, urlPrefix, isWiki)
}
// Render renders Markdown to HTML with all specific handling stuff.
func Render(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
return markup.Render("a.md", rawBytes, urlPrefix, metas)
}
// RenderString renders Markdown to HTML with special links and returns string type.
func RenderString(raw, urlPrefix string, metas map[string]string) string {
return markup.RenderString("a.md", raw, urlPrefix, metas)
}
// RenderWiki renders markdown wiki page to HTML and return HTML string
func RenderWiki(rawBytes []byte, urlPrefix string, metas map[string]string) string {
return markup.RenderWiki("a.md", rawBytes, urlPrefix, metas)
}
// IsMarkdownFile reports whether name looks like a Markdown file
// based on its extension.
func IsMarkdownFile(name string) bool {
return markup.IsMarkupFile(name, MarkupName)
}