Automatically render wiki TOC (#19873)

Automatically add sidebar in the wiki view containing a TOC for the wiki page.
Make the TOC collapsable

Signed-off-by: Andrew Thornton <art27@cantab.net>

modules/markup/markdown/goldmark.go

@@ -27,13 +27,6 @@ import (
 
 var byteMailto = []byte("mailto:")
 
-// Header holds the data about a header.
-type Header struct {
-	Level int
-	Text  string
-	ID    string
-}
-
 // ASTTransformer is a default transformer of the goldmark tree.
 type ASTTransformer struct{}
 
@@ -42,12 +35,13 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 	metaData := meta.GetItems(pc)
 	firstChild := node.FirstChild()
 	createTOC := false
-	toc := []Header{}
+	ctx := pc.Get(renderContextKey).(*markup.RenderContext)
 	rc := &RenderConfig{
 		Meta: "table",
 		Icon: "table",
 		Lang: "",
 	}
+
 	if metaData != nil {
 		rc.ToRenderConfig(metaData)
 
@@ -56,7 +50,7 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 			node.InsertBefore(node, firstChild, metaNode)
 		}
 		createTOC = rc.TOC
-		toc = make([]Header, 0, 100)
+		ctx.TableOfContents = make([]markup.Header, 0, 100)
 	}
 
 	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
@@ -66,23 +60,20 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 
 		switch v := n.(type) {
 		case *ast.Heading:
-			if createTOC {
-				text := n.Text(reader.Source())
-				header := Header{
-					Text:  util.BytesToReadOnlyString(text),
-					Level: v.Level,
-				}
-				if id, found := v.AttributeString("id"); found {
-					header.ID = util.BytesToReadOnlyString(id.([]byte))
-				}
-				toc = append(toc, header)
-			} else {
-				for _, attr := range v.Attributes() {
-					if _, ok := attr.Value.([]byte); !ok {
-						v.SetAttribute(attr.Name, []byte(fmt.Sprintf("%v", attr.Value)))
-					}
+			for _, attr := range v.Attributes() {
+				if _, ok := attr.Value.([]byte); !ok {
+					v.SetAttribute(attr.Name, []byte(fmt.Sprintf("%v", attr.Value)))
 				}
 			}
+			text := n.Text(reader.Source())
+			header := markup.Header{
+				Text:  util.BytesToReadOnlyString(text),
+				Level: v.Level,
+			}
+			if id, found := v.AttributeString("id"); found {
+				header.ID = util.BytesToReadOnlyString(id.([]byte))
+			}
+			ctx.TableOfContents = append(ctx.TableOfContents, header)
 		case *ast.Image:
 			// Images need two things:
 			//
@@ -199,12 +190,12 @@ func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc pa
 		return ast.WalkContinue, nil
 	})
 
-	if createTOC && len(toc) > 0 {
+	if createTOC && len(ctx.TableOfContents) > 0 {
 		lang := rc.Lang
 		if len(lang) == 0 {
 			lang = setting.Langs[0]
 		}
-		tocNode := createTOCNode(toc, lang)
+		tocNode := createTOCNode(ctx.TableOfContents, lang)
 		if tocNode != nil {
 			node.InsertBefore(node, firstChild, tocNode)
 		}

modules/markup/markdown/markdown.go

@@ -34,9 +34,10 @@ var (
 )
 
 var (
-	urlPrefixKey   = parser.NewContextKey()
-	isWikiKey      = parser.NewContextKey()
-	renderMetasKey = parser.NewContextKey()
+	urlPrefixKey     = parser.NewContextKey()
+	isWikiKey        = parser.NewContextKey()
+	renderMetasKey   = parser.NewContextKey()
+	renderContextKey = parser.NewContextKey()
 )
 
 type limitWriter struct {
@@ -67,6 +68,7 @@ func newParserContext(ctx *markup.RenderContext) parser.Context {
 	pc.Set(urlPrefixKey, ctx.URLPrefix)
 	pc.Set(isWikiKey, ctx.IsWiki)
 	pc.Set(renderMetasKey, ctx.Metas)
+	pc.Set(renderContextKey, ctx)
 	return pc
 }
 

modules/markup/markdown/toc.go

@@ -8,12 +8,13 @@ import (
 	"fmt"
 	"net/url"
 
+	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/translation/i18n"
 
 	"github.com/yuin/goldmark/ast"
 )
 
-func createTOCNode(toc []Header, lang string) ast.Node {
+func createTOCNode(toc []markup.Header, lang string) ast.Node {
 	details := NewDetails()
 	summary := NewSummary()