Re-render shortcode on template or data file change

Fixes  #1971

hugolib/handler_page.go

@@ -134,6 +134,6 @@ func commonConvert(p *Page, t tpl.Template) HandledResult {
 
 	p.Content = helpers.BytesToHTML(tmpContent)
 	p.TableOfContents = helpers.BytesToHTML(tmpTableOfContents)
-
+	p.rendered = true
 	return HandledResult{err: nil}
 }

hugolib/page.go

@@ -69,7 +69,8 @@ type Page struct {
 	linkTitle           string
 	frontmatter         []byte
 	rawContent          []byte
-	contentShortCodes   map[string]string
+	contentShortCodes   map[string]string // TODO(bep) this shouldn't be needed.
+	shortcodes          map[string]shortcode
 	plain               string // TODO should be []byte
 	plainWords          []string
 	plainInit           sync.Once
@@ -82,6 +83,7 @@ type Page struct {
 	Source
 	Position `json:"-"`
 	Node
+	rendered bool
 }
 
 type Source struct {
@@ -907,9 +909,15 @@ func (p *Page) ProcessShortcodes(t tpl.Template) {
 
 	// these short codes aren't used until after Page render,
 	// but processed here to avoid coupling
+	// TODO(bep) Move this and remove p.contentShortCodes
+	if !p.rendered {
 		tmpContent, tmpContentShortCodes, _ := extractAndRenderShortcodes(string(p.rawContent), p, t)
 		p.rawContent = []byte(tmpContent)
 		p.contentShortCodes = tmpContentShortCodes
+	} else {
+		// shortcode template may have changed, rerender
+		p.contentShortCodes = renderShortcodes(p.shortcodes, p, t)
+	}
 
 }
 

hugolib/shortcode.go

@@ -263,14 +263,30 @@ func renderShortcode(sc shortcode, parent *ShortcodeWithPage, p *Page, t tpl.Tem
 
 func extractAndRenderShortcodes(stringToParse string, p *Page, t tpl.Template) (string, map[string]string, error) {
 
+	if p.rendered {
+		panic("Illegal state: Page already marked as rendered, please reuse the shortcodes")
+	}
+
 	content, shortcodes, err := extractShortcodes(stringToParse, p, t)
-	renderedShortcodes := make(map[string]string)
 
 	if err != nil {
 		//  try to render what we have whilst logging the error
 		jww.ERROR.Println(err.Error())
 	}
 
+	// Save for reuse
+	// TODO(bep) refactor this
+	p.shortcodes = shortcodes
+
+	renderedShortcodes := renderShortcodes(shortcodes, p, t)
+
+	return content, renderedShortcodes, err
+
+}
+
+func renderShortcodes(shortcodes map[string]shortcode, p *Page, t tpl.Template) map[string]string {
+	renderedShortcodes := make(map[string]string)
+
 	for key, sc := range shortcodes {
 		if sc.err != nil {
 			// need to have something to replace with
@@ -280,8 +296,7 @@ func extractAndRenderShortcodes(stringToParse string, p *Page, t tpl.Template) (
 		}
 	}
 
-	return content, renderedShortcodes, err
+	return renderedShortcodes
-
 }
 
 var shortCodeIllegalState = errors.New("Illegal shortcode state")

hugolib/site.go

@@ -475,7 +475,6 @@ func (s *Site) ReBuild(events []fsnotify.Event) error {
 	s.resetPageBuildState()
 
 	// If a content file changes, we need to reload only it and re-render the entire site.
-	if len(sourceChanged) > 0 {
 
 	// First step is to read the changed files and (re)place them in site.Pages
 	// This includes processing any meta-data for that content
@@ -510,6 +509,14 @@ func (s *Site) ReBuild(events []fsnotify.Event) error {
 	go incrementalReadCollator(s, readResults, pageChan, fileConvChan, coordinator, errs)
 	go converterCollator(s, convertResults, errs)
 
+	if len(tmplChanged) > 0 || len(dataChanged) > 0 {
+		// Do not need to read the files again, but they need conversion
+		// for shortocde re-rendering.
+		for _, p := range s.Pages {
+			pageChan <- p
+		}
+	}
+
 	for _, ev := range sourceChanged {
 
 		if ev.Op&fsnotify.Remove == fsnotify.Remove {
@@ -560,6 +567,7 @@ func (s *Site) ReBuild(events []fsnotify.Event) error {
 
 	s.timerStep("read & convert pages from source")
 
+	if len(sourceChanged) > 0 {
 		s.setupPrevNext()
 		if err = s.BuildSiteMeta(); err != nil {
 			return err