forgejo/modules/markup/markdown/callout/github.go
2024-08-18 15:19:01 +02:00

140 lines
4.4 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// Copyright 2024 The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
// SPDX-License-Identifier: MIT
package callout
import (
"strings"
"code.gitea.io/gitea/modules/svg"
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/parser"
"github.com/yuin/goldmark/renderer"
"github.com/yuin/goldmark/renderer/html"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
type GitHubCalloutTransformer struct{}
// Transform transforms the given AST tree.
func (g *GitHubCalloutTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
supportedAttentionTypes := map[string]bool{
"note": true,
"tip": true,
"important": true,
"warning": true,
"caution": true,
}
_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
if !entering {
return ast.WalkContinue, nil
}
if v, ok := n.(*ast.Blockquote); ok {
if v.ChildCount() == 0 {
return ast.WalkContinue, nil
}
// We only want attention blockquotes when the AST looks like:
// Text: "["
// Text: "!TYPE"
// Text(SoftLineBreak): "]"
// grab these nodes and make sure we adhere to the attention blockquote structure
firstParagraph := v.FirstChild()
if firstParagraph.ChildCount() < 3 {
return ast.WalkContinue, nil
}
firstTextNode, ok := firstParagraph.FirstChild().(*ast.Text)
if !ok || string(firstTextNode.Text(reader.Source())) != "[" {
return ast.WalkContinue, nil
}
secondTextNode, ok := firstTextNode.NextSibling().(*ast.Text)
if !ok {
return ast.WalkContinue, nil
}
// If the second node's text isn't one of the supported attention
// types, continue walking.
secondTextNodeText := secondTextNode.Text(reader.Source())
attentionType := strings.ToLower(strings.TrimPrefix(string(secondTextNodeText), "!"))
if _, has := supportedAttentionTypes[attentionType]; !has {
return ast.WalkContinue, nil
}
thirdTextNode, ok := secondTextNode.NextSibling().(*ast.Text)
if !ok || string(thirdTextNode.Text(reader.Source())) != "]" {
return ast.WalkContinue, nil
}
// color the blockquote
v.SetAttributeString("class", []byte("attention-header attention-"+attentionType))
// create an emphasis to make it bold
attentionParagraph := ast.NewParagraph()
attentionParagraph.SetAttributeString("class", []byte("attention-title"))
emphasis := ast.NewEmphasis(2)
emphasis.SetAttributeString("class", []byte("attention-"+attentionType))
firstParagraph.InsertBefore(firstParagraph, firstTextNode, emphasis)
// capitalize first letter
attentionText := ast.NewString([]byte(strings.ToUpper(string(attentionType[0])) + attentionType[1:]))
// replace the ![TYPE] with a dedicated paragraph of icon+Type
emphasis.AppendChild(emphasis, attentionText)
attentionParagraph.AppendChild(attentionParagraph, NewAttention(attentionType))
attentionParagraph.AppendChild(attentionParagraph, emphasis)
firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
firstParagraph.RemoveChild(firstParagraph, firstTextNode)
firstParagraph.RemoveChild(firstParagraph, secondTextNode)
}
return ast.WalkContinue, nil
})
}
type GitHubCalloutHTMLRenderer struct {
html.Config
}
// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
func (r *GitHubCalloutHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
reg.Register(KindAttention, r.renderAttention)
}
// renderAttention renders a quote marked with i.e. "> **Note**" or "> **Warning**" with a corresponding svg
func (r *GitHubCalloutHTMLRenderer) renderAttention(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
if entering {
n := node.(*Attention)
var octiconName string
switch n.AttentionType {
case "note":
octiconName = "info"
case "tip":
octiconName = "light-bulb"
case "important":
octiconName = "report"
case "warning":
octiconName = "alert"
case "caution":
octiconName = "stop"
default:
octiconName = "info"
}
_, _ = w.WriteString(string(svg.RenderHTML("octicon-"+octiconName, 16, "attention-icon attention-"+n.AttentionType)))
}
return ast.WalkContinue, nil
}
func NewGitHubCalloutHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
r := &GitHubCalloutHTMLRenderer{
Config: html.NewConfig(),
}
for _, opt := range opts {
opt.SetHTMLOption(&r.Config)
}
return r
}