hugo/markup/blackfriday/convert.go
2020-12-03 13:12:58 +01:00

233 lines
6.7 KiB
Go

// 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 (
"unicode"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/markup/blackfriday/blackfriday_config"
"github.com/gohugoio/hugo/markup/converter"
"github.com/russross/blackfriday"
)
// Provider is the package entry point.
var Provider converter.ProviderProvider = provider{}
type provider struct {
}
func (p provider) New(cfg converter.ProviderConfig) (converter.Provider, error) {
defaultExtensions := getMarkdownExtensions(cfg.MarkupConfig.BlackFriday)
return converter.NewProvider("blackfriday", func(ctx converter.DocumentContext) (converter.Converter, error) {
b := cfg.MarkupConfig.BlackFriday
extensions := defaultExtensions
if ctx.ConfigOverrides != nil {
var err error
b, err = blackfriday_config.UpdateConfig(b, ctx.ConfigOverrides)
if err != nil {
return nil, err
}
extensions = getMarkdownExtensions(b)
}
return &blackfridayConverter{
ctx: ctx,
bf: b,
extensions: extensions,
cfg: cfg,
}, nil
}), nil
}
type blackfridayConverter struct {
ctx converter.DocumentContext
bf blackfriday_config.Config
extensions int
cfg converter.ProviderConfig
}
func (c *blackfridayConverter) SanitizeAnchorName(s string) string {
return SanitizedAnchorName(s)
}
// SanitizedAnchorName is how Blackfriday sanitizes anchor names.
// Implementation borrowed from https://github.com/russross/blackfriday/blob/a477dd1646916742841ed20379f941cfa6c5bb6f/block.go#L1464
func SanitizedAnchorName(text string) string {
var anchorName []rune
futureDash := false
for _, r := range text {
switch {
case unicode.IsLetter(r) || unicode.IsNumber(r):
if futureDash && len(anchorName) > 0 {
anchorName = append(anchorName, '-')
}
futureDash = false
anchorName = append(anchorName, unicode.ToLower(r))
default:
futureDash = true
}
}
return string(anchorName)
}
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) Supports(feature identity.Identity) bool {
return false
}
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 blackfriday_config.Config) 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 blackfriday_config.Config) 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)
_ converter.AnchorNameSanitizer = (*blackfridayConverter)(nil)
)