first-commit

modules/markup/markdown/transform_blockquote.go

@@ -0,0 +1,157 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/svg"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+)
+
+// renderAttention renders a quote marked with i.e. "> **Note**" or "> [!Warning]" with a corresponding svg
+func (r *HTMLRenderer) 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 "tip":
+			octiconName = "light-bulb"
+		case "important":
+			octiconName = "report"
+		case "warning":
+			octiconName = "alert"
+		case "caution":
+			octiconName = "stop"
+		default: // including "note"
+			octiconName = "info"
+		}
+		svgHTML := svg.RenderHTML("octicon-"+octiconName, 16, "attention-icon attention-"+n.AttentionType)
+		_, _ = w.WriteString(string(r.renderInternal.ProtectSafeAttrs(svgHTML)))
+	}
+	return ast.WalkContinue, nil
+}
+
+func (g *ASTTransformer) extractBlockquoteAttentionEmphasis(firstParagraph ast.Node, reader text.Reader) (string, []ast.Node) {
+	if firstParagraph.ChildCount() < 1 {
+		return "", nil
+	}
+	node1, ok := firstParagraph.FirstChild().(*ast.Emphasis)
+	if !ok {
+		return "", nil
+	}
+	val1 := string(node1.Text(reader.Source())) //nolint:staticcheck // Text is deprecated
+	attentionType := strings.ToLower(val1)
+	if g.attentionTypes.Contains(attentionType) {
+		return attentionType, []ast.Node{node1}
+	}
+	return "", nil
+}
+
+func (g *ASTTransformer) extractBlockquoteAttention2(firstParagraph ast.Node, reader text.Reader) (string, []ast.Node) {
+	if firstParagraph.ChildCount() < 2 {
+		return "", nil
+	}
+	node1, ok := firstParagraph.FirstChild().(*ast.Text)
+	if !ok {
+		return "", nil
+	}
+	node2, ok := node1.NextSibling().(*ast.Text)
+	if !ok {
+		return "", nil
+	}
+	val1 := string(node1.Segment.Value(reader.Source()))
+	val2 := string(node2.Segment.Value(reader.Source()))
+	if strings.HasPrefix(val1, `\[!`) && val2 == `\]` {
+		attentionType := strings.ToLower(val1[3:])
+		if g.attentionTypes.Contains(attentionType) {
+			return attentionType, []ast.Node{node1, node2}
+		}
+	}
+	return "", nil
+}
+
+func (g *ASTTransformer) extractBlockquoteAttention3(firstParagraph ast.Node, reader text.Reader) (string, []ast.Node) {
+	if firstParagraph.ChildCount() < 3 {
+		return "", nil
+	}
+	node1, ok := firstParagraph.FirstChild().(*ast.Text)
+	if !ok {
+		return "", nil
+	}
+	node2, ok := node1.NextSibling().(*ast.Text)
+	if !ok {
+		return "", nil
+	}
+	node3, ok := node2.NextSibling().(*ast.Text)
+	if !ok {
+		return "", nil
+	}
+	val1 := string(node1.Segment.Value(reader.Source()))
+	val2 := string(node2.Segment.Value(reader.Source()))
+	val3 := string(node3.Segment.Value(reader.Source()))
+	if val1 != "[" || val3 != "]" || !strings.HasPrefix(val2, "!") {
+		return "", nil
+	}
+
+	attentionType := strings.ToLower(val2[1:])
+	if g.attentionTypes.Contains(attentionType) {
+		return attentionType, []ast.Node{node1, node2, node3}
+	}
+	return "", nil
+}
+
+func (g *ASTTransformer) transformBlockquote(v *ast.Blockquote, reader text.Reader) (ast.WalkStatus, error) {
+	// We only want attention blockquotes when the AST looks like:
+	// > Text("[") Text("!TYPE") Text("]")
+	// > Text("\[!TYPE") TEXT("\]")
+	// > Text("**TYPE**")
+
+	// grab these nodes and make sure we adhere to the attention blockquote structure
+	firstParagraph := v.FirstChild()
+	if firstParagraph == nil {
+		return ast.WalkContinue, nil
+	}
+	g.applyElementDir(firstParagraph)
+
+	attentionType, processedNodes := g.extractBlockquoteAttentionEmphasis(firstParagraph, reader)
+	if attentionType == "" {
+		attentionType, processedNodes = g.extractBlockquoteAttention2(firstParagraph, reader)
+	}
+	if attentionType == "" {
+		attentionType, processedNodes = g.extractBlockquoteAttention3(firstParagraph, reader)
+	}
+	if attentionType == "" {
+		return ast.WalkContinue, nil
+	}
+
+	// color the blockquote
+	v.SetAttributeString(g.renderInternal.SafeAttr("class"), []byte(g.renderInternal.SafeValue("attention-header attention-"+attentionType)))
+
+	// create an emphasis to make it bold
+	attentionParagraph := ast.NewParagraph()
+	g.applyElementDir(attentionParagraph)
+	emphasis := ast.NewEmphasis(2)
+	emphasis.SetAttributeString(g.renderInternal.SafeAttr("class"), []byte(g.renderInternal.SafeValue("attention-"+attentionType)))
+
+	attentionAstString := ast.NewString([]byte(cases.Title(language.English).String(attentionType)))
+
+	// replace the ![TYPE] with a dedicated paragraph of icon+Type
+	emphasis.AppendChild(emphasis, attentionAstString)
+	attentionParagraph.AppendChild(attentionParagraph, NewAttention(attentionType))
+	attentionParagraph.AppendChild(attentionParagraph, emphasis)
+	firstParagraph.Parent().InsertBefore(firstParagraph.Parent(), firstParagraph, attentionParagraph)
+	for _, processed := range processedNodes {
+		firstParagraph.RemoveChild(firstParagraph, processed)
+	}
+	if firstParagraph.ChildCount() == 0 {
+		firstParagraph.Parent().RemoveChild(firstParagraph.Parent(), firstParagraph)
+	}
+	return ast.WalkContinue, nil
+}