chore: introduce HTMLBuilder (#37688)

modules/htmlutil/html.go

@@ -83,3 +83,34 @@ func HTMLPrintTag(w io.Writer, tag template.HTML, attrs map[string]string) (writ
 	written += n
 	return written, err
 }
+
+func EscapeString(s string) template.HTML {
+	return template.HTML(template.HTMLEscapeString(s))
+}
+
+type HTMLBuilder struct {
+	sb strings.Builder
+}
+
+func (b *HTMLBuilder) WriteString(s string) *HTMLBuilder {
+	b.sb.WriteString(template.HTMLEscapeString(s))
+	return b
+}
+
+func (b *HTMLBuilder) WriteHTML(s template.HTML) *HTMLBuilder {
+	b.sb.WriteString(string(s))
+	return b
+}
+
+func (b *HTMLBuilder) WriteFormat(fmt template.HTML, args ...any) *HTMLBuilder {
+	_, _ = HTMLPrintf(&b.sb, fmt, args...)
+	return b
+}
+
+func (b *HTMLBuilder) HTMLString() template.HTML {
+	return template.HTML(b.sb.String())
+}
+
+func (b *HTMLBuilder) String() string {
+	return b.sb.String()
+}

modules/htmlutil/html_test.go

@@ -22,3 +22,10 @@ func TestHTMLFormat(t *testing.T) {
 	assert.Equal(t, template.HTML("&lt;&gt;"), HTMLFormat("%s", template.URL("<>")))
 	assert.Equal(t, template.HTML("&amp;StringMethod &amp;StringMethod"), HTMLFormat("%s %s", testStringer{}, &testStringer{}))
 }
+
+func TestHTMLBuilder(t *testing.T) {
+	b := &HTMLBuilder{}
+	b.WriteString("<").WriteHTML("<hr>").WriteFormat("<span>%s%s</span>", ">", EscapeString(">"))
+	assert.Equal(t, "&lt;<hr><span>&gt;&gt;</span>", b.String())
+	assert.Equal(t, template.HTML("&lt;<hr><span>&gt;&gt;</span>"), b.HTMLString())
+}

modules/markup/internal/renderinternal.go

@@ -77,6 +77,7 @@ func (r *RenderInternal) ProtectSafeAttrs(content template.HTML) template.HTML {
 }
 
 func (r *RenderInternal) FormatWithSafeAttrs(w io.Writer, fmt template.HTML, a ...any) error {
-	_, err := w.Write([]byte(r.ProtectSafeAttrs(htmlutil.HTMLFormat(fmt, a...))))
+	htmlStr := r.ProtectSafeAttrs(htmlutil.HTMLFormat(fmt, a...))
+	_, err := io.WriteString(w, string(htmlStr))
 	return err
 }

modules/markup/orgmode/orgmode.go

@@ -106,31 +106,27 @@ func (r *orgWriter) resolveLink(link string) string {
 // WriteRegularLink renders images, links or videos
 func (r *orgWriter) WriteRegularLink(l org.RegularLink) {
 	link := r.resolveLink(l.URL)
-
-	printHTML := func(html template.HTML, a ...any) {
-		_, _ = fmt.Fprint(r, htmlutil.HTMLFormat(html, a...))
-	}
 	// Inspired by https://github.com/niklasfasching/go-org/blob/6eb20dbda93cb88c3503f7508dc78cbbc639378f/org/html_writer.go#L406-L427
 	switch l.Kind() {
 	case "image":
 		if l.Description == nil {
-			printHTML(`<img src="%s" alt="%s">`, link, link)
+			_, _ = htmlutil.HTMLPrintf(r, `<img src="%s" alt="%s">`, link, link)
 		} else {
 			imageSrc := r.resolveLink(org.String(l.Description...))
-			printHTML(`<a href="%s"><img src="%s" alt="%s"></a>`, link, imageSrc, imageSrc)
+			_, _ = htmlutil.HTMLPrintf(r, `<a href="%s"><img src="%s" alt="%s"></a>`, link, imageSrc, imageSrc)
 		}
 	case "video":
 		if l.Description == nil {
-			printHTML(`<video src="%s">%s</video>`, link, link)
+			_, _ = htmlutil.HTMLPrintf(r, `<video src="%s">%s</video>`, link, link)
 		} else {
 			videoSrc := r.resolveLink(org.String(l.Description...))
-			printHTML(`<a href="%s"><video src="%s">%s</video></a>`, link, videoSrc, videoSrc)
+			_, _ = htmlutil.HTMLPrintf(r, `<a href="%s"><video src="%s">%s</video></a>`, link, videoSrc, videoSrc)
 		}
 	default:
 		var description any = link
 		if l.Description != nil {
 			description = template.HTML(r.WriteNodesAsString(l.Description...)) // orgmode HTMLWriter outputs HTML content
 		}
-		printHTML(`<a href="%s">%s</a>`, link, description)
+		_, _ = htmlutil.HTMLPrintf(r, `<a href="%s">%s</a>`, link, description)
 	}
 }

modules/web/router.go

@@ -260,7 +260,7 @@ func (r *Router) normalizeRequestPath(resp http.ResponseWriter, req *http.Reques
 			// do not respond to other requests, to simulate a real sub-path environment
 			resp.Header().Add("Content-Type", "text/html; charset=utf-8")
 			resp.WriteHeader(http.StatusNotFound)
-			_, _ = resp.Write([]byte(htmlutil.HTMLFormat(`404 page not found, sub-path is: <a href="%s">%s</a>`, setting.AppSubURL, setting.AppSubURL)))
+			_, _ = htmlutil.HTMLPrintf(resp, `404 page not found, sub-path is: <a href="%s">%s</a>`, setting.AppSubURL, setting.AppSubURL)
 			return
 		}
 		normalized = true

routers/web/repo/view_home.go

@@ -276,7 +276,7 @@ func handleRepoViewSubmodule(ctx *context.Context, commitSubmoduleFile *git.Comm
 	redirectLink := submoduleWebLink.CommitWebLink
 	if isViewHomeOnlyContent(ctx) {
 		ctx.Resp.Header().Set("Content-Type", "text/html; charset=utf-8")
-		_, _ = ctx.Resp.Write([]byte(htmlutil.HTMLFormat(`<a href="%s">%s</a>`, redirectLink, redirectLink)))
+		_, _ = htmlutil.HTMLPrintf(ctx.Resp, `<a href="%s">%s</a>`, redirectLink, redirectLink)
 	} else if !httplib.IsCurrentGiteaSiteURL(ctx, redirectLink) {
 		// don't auto-redirect to external URL, to avoid open redirect or phishing
 		ctx.Data["NotFoundPrompt"] = redirectLink