Add site-wide/per-page [blackfriday] extensions option

helpers/content.go

@@ -28,6 +28,7 @@ import (
 	jww "github.com/spf13/jwalterweatherman"
 
 	"strings"
+	"sync"
 )
 
 // Length of the summary that Hugo extracts from a content.
@@ -36,6 +37,30 @@ var SummaryLength = 70
 // Custom divider <!--more--> let's user define where summarization ends.
 var SummaryDivider = []byte("<!--more-->")
 
+type Blackfriday struct {
+	AngledQuotes   bool
+	Fractions      bool
+	PlainIdAnchors bool
+	Extensions     []string
+}
+
+var blackfridayExtensionMap = map[string]int{
+	"noIntraEmphasis":        blackfriday.EXTENSION_NO_INTRA_EMPHASIS,
+	"tables":                 blackfriday.EXTENSION_TABLES,
+	"fencedCode":             blackfriday.EXTENSION_FENCED_CODE,
+	"autolink":               blackfriday.EXTENSION_AUTOLINK,
+	"strikethrough":          blackfriday.EXTENSION_STRIKETHROUGH,
+	"laxHtmlBlocks":          blackfriday.EXTENSION_LAX_HTML_BLOCKS,
+	"spaceHeaders":           blackfriday.EXTENSION_SPACE_HEADERS,
+	"hardLineBreak":          blackfriday.EXTENSION_HARD_LINE_BREAK,
+	"tabSizeEight":           blackfriday.EXTENSION_TAB_SIZE_EIGHT,
+	"footnotes":              blackfriday.EXTENSION_FOOTNOTES,
+	"noEmptyLineBeforeBlock": blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK,
+	"headerIds":              blackfriday.EXTENSION_HEADER_IDS,
+	"titleblock":             blackfriday.EXTENSION_TITLEBLOCK,
+	"autoHeaderIds":          blackfriday.EXTENSION_AUTO_HEADER_IDS,
+}
+
 // StripHTML accepts a string, strips out all HTML tags and returns it.
 func StripHTML(s string) string {
 	output := ""
@@ -87,7 +112,7 @@ func GetHtmlRenderer(defaultFlags int, ctx RenderingContext) blackfriday.Rendere
 
 	b := len(ctx.DocumentId) != 0
 
-	if m, ok := ctx.ConfigFlags["plainIdAnchors"]; b && ((ok && !m) || !ok) {
+	if b && !ctx.getConfig().PlainIdAnchors {
 		renderParameters.FootnoteAnchorPrefix = ctx.DocumentId + ":" + renderParameters.FootnoteAnchorPrefix
 		renderParameters.HeaderIDSuffix = ":" + ctx.DocumentId
 	}
@@ -99,40 +124,40 @@ func GetHtmlRenderer(defaultFlags int, ctx RenderingContext) blackfriday.Rendere
 	htmlFlags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
 	htmlFlags |= blackfriday.HTML_FOOTNOTE_RETURN_LINKS
 
-	var angledQuotes bool
-
-	if m, ok := ctx.ConfigFlags["angledQuotes"]; ok {
-		angledQuotes = m
-	}
-
-	if angledQuotes {
+	if ctx.getConfig().AngledQuotes {
 		htmlFlags |= blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES
 	}
 
-	if m, ok := ctx.ConfigFlags["fractions"]; ok && !m {
+	if !ctx.getConfig().Fractions {
 		htmlFlags &^= blackfriday.HTML_SMARTYPANTS_FRACTIONS
 	}
 
 	return blackfriday.HtmlRendererWithParameters(htmlFlags, "", "", renderParameters)
 }
 
-func GetMarkdownExtensions() int {
-	return 0 | blackfriday.EXTENSION_NO_INTRA_EMPHASIS |
+func GetMarkdownExtensions(ctx RenderingContext) int {
+	flags := 0 | blackfriday.EXTENSION_NO_INTRA_EMPHASIS |
 		blackfriday.EXTENSION_TABLES | blackfriday.EXTENSION_FENCED_CODE |
 		blackfriday.EXTENSION_AUTOLINK | blackfriday.EXTENSION_STRIKETHROUGH |
 		blackfriday.EXTENSION_SPACE_HEADERS | blackfriday.EXTENSION_FOOTNOTES |
 		blackfriday.EXTENSION_HEADER_IDS | blackfriday.EXTENSION_AUTO_HEADER_IDS
+	for _, extension := range ctx.getConfig().Extensions {
+		if flag, ok := blackfridayExtensionMap[extension]; ok {
+			flags |= flag
+		}
+	}
+	return flags
 }
 
 func MarkdownRender(ctx RenderingContext) []byte {
 	return blackfriday.Markdown(ctx.Content, GetHtmlRenderer(0, ctx),
-		GetMarkdownExtensions())
+		GetMarkdownExtensions(ctx))
 }
 
 func MarkdownRenderWithTOC(ctx RenderingContext) []byte {
 	return blackfriday.Markdown(ctx.Content,
 		GetHtmlRenderer(blackfriday.HTML_TOC, ctx),
-		GetMarkdownExtensions())
+		GetMarkdownExtensions(ctx))
 }
 
 // ExtractTOC extracts Table of Contents from content.
@@ -172,10 +197,20 @@ func ExtractTOC(content []byte) (newcontent []byte, toc []byte) {
 }
 
 type RenderingContext struct {
-	Content     []byte
-	PageFmt     string
-	DocumentId  string
-	ConfigFlags map[string]bool
+	Content    []byte
+	PageFmt    string
+	DocumentId string
+	Config     *Blackfriday
+	configInit sync.Once
+}
+
+func (c *RenderingContext) getConfig() *Blackfriday {
+	c.configInit.Do(func() {
+		if c.Config == nil {
+			c.Config = new(Blackfriday)
+		}
+	})
+	return c.Config
 }
 
 func RenderBytesWithTOC(ctx RenderingContext) []byte {
@@ -261,8 +296,8 @@ func GetRstContent(content []byte) string {
 		path, err = exec.LookPath("rst2html.py")
 		if err != nil {
 			jww.ERROR.Println("rst2html / rst2html.py not found in $PATH: Please install.\n",
-			                  "                 Leaving reStructuredText content unrendered.")
-			return(string(content))
+				"                 Leaving reStructuredText content unrendered.")
+			return (string(content))
 		}
 	}