Change markdown rendering from blackfriday to goldmark (#9533)

* Move to goldmark

Markdown rendering moved from blackfriday to the goldmark.

Multiple subtle changes required to the goldmark extensions to keep
current rendering and defaults.

Can go further with goldmark linkify and have this work within markdown
rendering making the link processor unnecessary.

Need to think about how to go about allowing extensions - at present it
seems that these would be hard to do without recompilation.

* linter fixes

Co-authored-by: Lauris BH <lauris@nix.lv>
This commit is contained in:
zeripath 2019-12-31 01:53:28 +00:00 committed by Lauris BH
parent 0c07f1de5b
commit 27757714d0
83 changed files with 13838 additions and 6297 deletions

View file

@ -7,161 +7,83 @@ package markdown
import (
"bytes"
"io"
"strings"
"sync"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/markup"
"code.gitea.io/gitea/modules/markup/common"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
giteautil "code.gitea.io/gitea/modules/util"
"github.com/russross/blackfriday/v2"
"github.com/yuin/goldmark"
"github.com/yuin/goldmark/extension"
"github.com/yuin/goldmark/parser"
"github.com/yuin/goldmark/renderer"
"github.com/yuin/goldmark/renderer/html"
"github.com/yuin/goldmark/util"
)
// Renderer is a extended version of underlying render object.
type Renderer struct {
blackfriday.Renderer
URLPrefix string
IsWiki bool
var converter goldmark.Markdown
var once = sync.Once{}
var urlPrefixKey = parser.NewContextKey()
var isWikiKey = parser.NewContextKey()
// NewGiteaParseContext creates a parser.Context with the gitea context set
func NewGiteaParseContext(urlPrefix string, isWiki bool) parser.Context {
pc := parser.NewContext(parser.WithIDs(newPrefixedIDs()))
pc.Set(urlPrefixKey, urlPrefix)
pc.Set(isWikiKey, isWiki)
return pc
}
var byteMailto = []byte("mailto:")
var htmlEscaper = [256][]byte{
'&': []byte("&amp;"),
'<': []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,
FootnoteAnchorPrefix: "user-content-",
HeadingIDPrefix: "user-content-",
}),
URLPrefix: urlPrefix,
IsWiki: wikiMarkdown,
once.Do(func() {
converter = goldmark.New(
goldmark.WithExtensions(extension.Table,
extension.Strikethrough,
extension.TaskList,
extension.DefinitionList,
common.FootnoteExtension,
extension.NewTypographer(
extension.WithTypographicSubstitutions(extension.TypographicSubstitutions{
extension.EnDash: nil,
extension.EmDash: nil,
}),
),
),
goldmark.WithParserOptions(
parser.WithAttribute(),
parser.WithAutoHeadingID(),
parser.WithASTTransformers(
util.Prioritized(&GiteaASTTransformer{}, 10000),
),
),
goldmark.WithRendererOptions(
html.WithUnsafe(),
),
)
// Override the original Tasklist renderer!
converter.Renderer().AddOptions(
renderer.WithNodeRenderers(
util.Prioritized(NewTaskCheckBoxHTMLRenderer(), 1000),
),
)
if setting.Markdown.EnableHardLineBreak {
converter.Renderer().AddOptions(html.WithHardWraps())
}
})
pc := NewGiteaParseContext(urlPrefix, wikiMarkdown)
var buf bytes.Buffer
if err := converter.Convert(giteautil.NormalizeEOL(body), &buf, parser.WithContext(pc)); err != nil {
log.Error("Unable to render: %v", err)
}
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)
return markup.SanitizeReader(&buf).Bytes()
}
var (
@ -174,8 +96,7 @@ func init() {
}
// Parser implements markup.Parser
type Parser struct {
}
type Parser struct{}
// Name implements markup.Parser
func (Parser) Name() string {