gotosocial/internal/text/markdown.go

92 lines
2.5 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// 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"
"codeberg.org/gruf/go-byteutil"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/log"
"github.com/superseriousbusiness/gotosocial/internal/regexes"
"github.com/yuin/goldmark"
"github.com/yuin/goldmark/extension"
"github.com/yuin/goldmark/renderer/html"
)
// FromMarkdown fulfils FormatFunc by parsing
// the given markdown input into a FormatResult.
func (f *Formatter) FromMarkdown(
ctx context.Context,
parseMention gtsmodel.ParseMentionFunc,
authorID string,
statusID string,
input string,
) *FormatResult {
result := new(FormatResult)
// Instantiate goldmark parser for
// markdown, using custom renderer
// to add hashtag/mention links.
md := goldmark.New(
goldmark.WithRendererOptions(
html.WithXHTML(),
html.WithHardWraps(),
// Allows raw HTML. We sanitize
// at the end so this is OK.
html.WithUnsafe(),
),
goldmark.WithExtensions(
&customRenderer{
ctx,
f.db,
parseMention,
authorID,
statusID,
false, // emojiOnly = false.
result,
},
// Turns URLs into links.
extension.NewLinkify(
extension.WithLinkifyURLRegexp(regexes.LinkScheme),
),
extension.Strikethrough,
),
)
// Convert input string to bytes
// without performing any allocs.
bInput := byteutil.S2B(input)
// Parse input into HTML.
var htmlBytes bytes.Buffer
if err := md.Convert(
bInput,
&htmlBytes,
); err != nil {
log.Errorf(ctx, "error formatting markdown input to HTML: %s", err)
}
// Clean and shrink HTML.
result.HTML = byteutil.B2S(htmlBytes.Bytes())
result.HTML = SanitizeToHTML(result.HTML)
result.HTML = MinifyHTML(result.HTML)
return result
}