forgejo/modules/markup/markdown/markdown.go
zeripath 27757714d0 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>
2019-12-31 03:53:28 +02:00

135 lines
3.8 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"
"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"
giteautil "code.gitea.io/gitea/modules/util"
"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"
)
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
}
// RenderRaw renders Markdown to HTML without handling special links.
func RenderRaw(body []byte, urlPrefix string, wikiMarkdown bool) []byte {
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)
}
return markup.SanitizeReader(&buf).Bytes()
}
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)
}