gitea/modules/markup/markdown/transform_codespan.go

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// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markdown
import (
"bytes"
"fmt"
"strings"
"code.gitea.io/gitea/modules/markup"
"github.com/microcosm-cc/bluemonday/css"
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/renderer/html"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
// renderCodeSpan renders CodeSpan elements (like goldmark upstream does) but also renders ColorPreview elements.
// See #21474 for reference
func (r *HTMLRenderer) renderCodeSpan(w util.BufWriter, source []byte, n ast.Node, entering bool) (ast.WalkStatus, error) {
if entering {
if n.Attributes() != nil {
_, _ = w.WriteString("<code")
html.RenderAttributes(w, n, html.CodeAttributeFilter)
_ = w.WriteByte('>')
} else {
_, _ = w.WriteString("<code>")
}
for c := n.FirstChild(); c != nil; c = c.NextSibling() {
switch v := c.(type) {
case *ast.Text:
segment := v.Segment
value := segment.Value(source)
if bytes.HasSuffix(value, []byte("\n")) {
r.Writer.RawWrite(w, value[:len(value)-1])
r.Writer.RawWrite(w, []byte(" "))
} else {
r.Writer.RawWrite(w, value)
}
case *ColorPreview:
_, _ = w.WriteString(fmt.Sprintf(`<span class="color-preview" style="background-color: %v"></span>`, string(v.Color)))
}
}
return ast.WalkSkipChildren, nil
}
_, _ = w.WriteString("</code>")
return ast.WalkContinue, nil
}
// cssColorHandler checks if a string is a render-able CSS color value.
// The code is from "github.com/microcosm-cc/bluemonday/css.ColorHandler", except that it doesn't handle color words like "red".
func cssColorHandler(value string) bool {
value = strings.ToLower(value)
if css.HexRGB.MatchString(value) {
return true
}
if css.RGB.MatchString(value) {
return true
}
if css.RGBA.MatchString(value) {
return true
}
if css.HSL.MatchString(value) {
return true
}
return css.HSLA.MatchString(value)
}
func (g *ASTTransformer) transformCodeSpan(ctx *markup.RenderContext, v *ast.CodeSpan, reader text.Reader) {
colorContent := v.Text(reader.Source())
if cssColorHandler(string(colorContent)) {
v.AppendChild(v, NewColorPreview(colorContent))
}
}