Prepare for Goldmark

This commmit prepares for the addition of Goldmark as the new Markdown renderer in Hugo.

This introduces a new `markup` package with some common interfaces and each implementation in its own package.

See #5963

1 files changed, 224 insertions, 0 deletions

diff --git a/markup/blackfriday/convert.go b/markup/blackfriday/convert.go
new file mode 100644
index 000000000..f9d957a4e
--- /dev/null
+++ b/markup/blackfriday/convert.go
@@ -0,0 +1,224 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package blackfriday converts Markdown to HTML using Blackfriday v1.
+package blackfriday
+
+import (
+	"github.com/gohugoio/hugo/markup/converter"
+	"github.com/gohugoio/hugo/markup/internal"
+	"github.com/russross/blackfriday"
+)
+
+// Provider is the package entry point.
+var Provider converter.NewProvider = provider{}
+
+type provider struct {
+}
+
+func (p provider) New(cfg converter.ProviderConfig) (converter.Provider, error) {
+	defaultBlackFriday, err := internal.NewBlackfriday(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	defaultExtensions := getMarkdownExtensions(defaultBlackFriday)
+
+	pygmentsCodeFences := cfg.Cfg.GetBool("pygmentsCodeFences")
+	pygmentsCodeFencesGuessSyntax := cfg.Cfg.GetBool("pygmentsCodeFencesGuessSyntax")
+	pygmentsOptions := cfg.Cfg.GetString("pygmentsOptions")
+
+	var n converter.NewConverter = func(ctx converter.DocumentContext) (converter.Converter, error) {
+		b := defaultBlackFriday
+		extensions := defaultExtensions
+
+		if ctx.ConfigOverrides != nil {
+			var err error
+			b, err = internal.UpdateBlackFriday(b, ctx.ConfigOverrides)
+			if err != nil {
+				return nil, err
+			}
+			extensions = getMarkdownExtensions(b)
+		}
+
+		return &blackfridayConverter{
+			ctx:        ctx,
+			bf:         b,
+			extensions: extensions,
+			cfg:        cfg,
+
+			pygmentsCodeFences:            pygmentsCodeFences,
+			pygmentsCodeFencesGuessSyntax: pygmentsCodeFencesGuessSyntax,
+			pygmentsOptions:               pygmentsOptions,
+		}, nil
+	}
+
+	return n, nil
+
+}
+
+type blackfridayConverter struct {
+	ctx        converter.DocumentContext
+	bf         *internal.BlackFriday
+	extensions int
+
+	pygmentsCodeFences            bool
+	pygmentsCodeFencesGuessSyntax bool
+	pygmentsOptions               string
+
+	cfg converter.ProviderConfig
+}
+
+func (c *blackfridayConverter) AnchorSuffix() string {
+	if c.bf.PlainIDAnchors {
+		return ""
+	}
+	return ":" + c.ctx.DocumentID
+}
+
+func (c *blackfridayConverter) Convert(ctx converter.RenderContext) (converter.Result, error) {
+	r := c.getHTMLRenderer(ctx.RenderTOC)
+
+	return converter.Bytes(blackfriday.Markdown(ctx.Src, r, c.extensions)), nil
+
+}
+
+func (c *blackfridayConverter) getHTMLRenderer(renderTOC bool) blackfriday.Renderer {
+	flags := getFlags(renderTOC, c.bf)
+
+	documentID := c.ctx.DocumentID
+
+	renderParameters := blackfriday.HtmlRendererParameters{
+		FootnoteAnchorPrefix:       c.bf.FootnoteAnchorPrefix,
+		FootnoteReturnLinkContents: c.bf.FootnoteReturnLinkContents,
+	}
+
+	if documentID != "" && !c.bf.PlainIDAnchors {
+		renderParameters.FootnoteAnchorPrefix = documentID + ":" + renderParameters.FootnoteAnchorPrefix
+		renderParameters.HeaderIDSuffix = ":" + documentID
+	}
+
+	return &hugoHTMLRenderer{
+		c:        c,
+		Renderer: blackfriday.HtmlRendererWithParameters(flags, "", "", renderParameters),
+	}
+}
+
+func getFlags(renderTOC bool, cfg *internal.BlackFriday) int {
+
+	var flags int
+
+	if renderTOC {
+		flags = blackfriday.HTML_TOC
+	}
+
+	flags |= blackfriday.HTML_USE_XHTML
+	flags |= blackfriday.HTML_FOOTNOTE_RETURN_LINKS
+
+	if cfg.Smartypants {
+		flags |= blackfriday.HTML_USE_SMARTYPANTS
+	}
+
+	if cfg.SmartypantsQuotesNBSP {
+		flags |= blackfriday.HTML_SMARTYPANTS_QUOTES_NBSP
+	}
+
+	if cfg.AngledQuotes {
+		flags |= blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES
+	}
+
+	if cfg.Fractions {
+		flags |= blackfriday.HTML_SMARTYPANTS_FRACTIONS
+	}
+
+	if cfg.HrefTargetBlank {
+		flags |= blackfriday.HTML_HREF_TARGET_BLANK
+	}
+
+	if cfg.NofollowLinks {
+		flags |= blackfriday.HTML_NOFOLLOW_LINKS
+	}
+
+	if cfg.NoreferrerLinks {
+		flags |= blackfriday.HTML_NOREFERRER_LINKS
+	}
+
+	if cfg.SmartDashes {
+		flags |= blackfriday.HTML_SMARTYPANTS_DASHES
+	}
+
+	if cfg.LatexDashes {
+		flags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
+	}
+
+	if cfg.SkipHTML {
+		flags |= blackfriday.HTML_SKIP_HTML
+	}
+
+	return flags
+}
+
+func getMarkdownExtensions(cfg *internal.BlackFriday) int {
+	// Default Blackfriday common extensions
+	commonExtensions := 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_HEADER_IDS |
+		blackfriday.EXTENSION_BACKSLASH_LINE_BREAK |
+		blackfriday.EXTENSION_DEFINITION_LISTS
+
+	// Extra Blackfriday extensions that Hugo enables by default
+	flags := commonExtensions |
+		blackfriday.EXTENSION_AUTO_HEADER_IDS |
+		blackfriday.EXTENSION_FOOTNOTES
+
+	for _, extension := range cfg.Extensions {
+		if flag, ok := blackfridayExtensionMap[extension]; ok {
+			flags |= flag
+		}
+	}
+	for _, extension := range cfg.ExtensionsMask {
+		if flag, ok := blackfridayExtensionMap[extension]; ok {
+			flags &= ^flag
+		}
+	}
+	return flags
+}
+
+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,
+	"backslashLineBreak":     blackfriday.EXTENSION_BACKSLASH_LINE_BREAK,
+	"definitionLists":        blackfriday.EXTENSION_DEFINITION_LISTS,
+	"joinLines":              blackfriday.EXTENSION_JOIN_LINES,
+}
+
+var (
+	_ converter.DocumentInfo = (*blackfridayConverter)(nil)
+)