GoToSocial/internal/text/markdown.go

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/*
GoToSocial
2021-12-20 18:42:19 +01:00
Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package text
import (
"bytes"
"context"
"io"
"github.com/russross/blackfriday/v2"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/log"
"github.com/tdewolff/minify/v2"
"github.com/tdewolff/minify/v2/html"
)
var (
bfExtensions = blackfriday.CommonExtensions | blackfriday.HardLineBreak | blackfriday.Footnotes
m *minify.M
)
type renderer struct {
f *formatter
ctx context.Context
mentions []*gtsmodel.Mention
tags []*gtsmodel.Tag
blackfriday.HTMLRenderer
}
func (r *renderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
if node.Type == blackfriday.Text {
// call RenderNode to do the html escaping
var buff bytes.Buffer
status := r.HTMLRenderer.RenderNode(&buff, node, entering)
html := buff.String()
html = r.f.ReplaceTags(r.ctx, html, r.tags)
html = r.f.ReplaceMentions(r.ctx, html, r.mentions)
// we don't have much recourse if this fails
_, err := io.WriteString(w, html)
if err != nil {
log.Errorf("error outputting markdown text: %s", err)
}
return status
}
return r.HTMLRenderer.RenderNode(w, node, entering)
}
func (f *formatter) FromMarkdown(ctx context.Context, md string, mentions []*gtsmodel.Mention, tags []*gtsmodel.Tag) string {
renderer := &renderer{
f: f,
ctx: ctx,
mentions: mentions,
tags: tags,
HTMLRenderer: *blackfriday.NewHTMLRenderer(blackfriday.HTMLRendererParameters{
Flags: blackfriday.CommonHTMLFlags,
}),
}
// parse markdown, use custom renderer to add hashtag/mention links
contentBytes := blackfriday.Run([]byte(md), blackfriday.WithExtensions(bfExtensions), blackfriday.WithRenderer(renderer))
// clean anything dangerous out of it
content := SanitizeHTML(string(contentBytes))
if m == nil {
m = minify.New()
m.Add("text/html", &html.Minifier{
KeepEndTags: true,
KeepQuotes: true,
})
}
minified, err := m.String("text/html", content)
if err != nil {
log.Errorf("error minifying markdown text: %s", err)
}
return minified
}