hugo/helpers/content.go
Bjørn Erik Pedersen 80230f26a3
Add support for theme composition and inheritance
This commit adds support for theme composition and inheritance in Hugo.

With this, it helps thinking about a theme as a set of ordered components:

```toml
theme = ["my-shortcodes", "base-theme", "hyde"]
```

The theme definition example above in `config.toml` creates a theme with the 3 components with presedence from left to right.

So, Hugo will, for any given file, data entry etc., look first in the project, and then in `my-shortcode`, `base-theme` and lastly `hyde`.

Hugo uses two different algorithms to merge the filesystems, depending on the file type:

* For `i18n` and `data` files, Hugo merges deeply using the translation id and data key inside the files.
* For `static`, `layouts` (templates) and `archetypes` files, these are merged on file level. So the left-most file will be chosen.

The name used in the `theme` definition above must match a folder in `/your-site/themes`, e.g. `/your-site/themes/my-shortcodes`. There are  plans to improve on this and get a URL scheme so this can be resolved automatically.

Also note that a component that is part of a theme can have its own configuration file, e.g. `config.toml`. There are currently some restrictions to what a theme component can configure:

* `params` (global and per language)
* `menu` (global and per language)
* `outputformats` and `mediatypes`

The same rules apply here: The left-most param/menu etc. with the same ID will win. There are some hidden and experimental namespace support in the above, which we will work to improve in the future, but theme authors are encouraged to create their own namespaces to avoid naming conflicts.

A final note: Themes/components can also have a `theme` definition in their `config.toml` and similar, which is the "inheritance" part of this commit's title. This is currently not supported by the Hugo theme site. We will have to wait for some "auto dependency" feature to be implemented for that to happen, but this can be a powerful feature if you want to create your own theme-variant based on others.

Fixes #4460
Fixes #4450
2018-06-10 23:55:20 +02:00

752 lines
21 KiB
Go

// Copyright 2015 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 helpers implements general utility functions that work with
// and on content. The helper functions defined here lay down the
// foundation of how Hugo works with files and filepaths, and perform
// string operations on content.
package helpers
import (
"bytes"
"fmt"
"html/template"
"os/exec"
"unicode"
"unicode/utf8"
"github.com/gohugoio/hugo/common/maps"
"github.com/chaseadamsio/goorgeous"
bp "github.com/gohugoio/hugo/bufferpool"
"github.com/gohugoio/hugo/config"
"github.com/miekg/mmark"
"github.com/mitchellh/mapstructure"
"github.com/russross/blackfriday"
jww "github.com/spf13/jwalterweatherman"
"strings"
)
// SummaryDivider denotes where content summarization should end. The default is "<!--more-->".
var SummaryDivider = []byte("<!--more-->")
// ContentSpec provides functionality to render markdown content.
type ContentSpec struct {
BlackFriday *BlackFriday
footnoteAnchorPrefix string
footnoteReturnLinkContents string
// SummaryLength is the length of the summary that Hugo extracts from a content.
summaryLength int
BuildFuture bool
BuildExpired bool
BuildDrafts bool
Highlight func(code, lang, optsStr string) (string, error)
defatultPygmentsOpts map[string]string
cfg config.Provider
}
// NewContentSpec returns a ContentSpec initialized
// with the appropriate fields from the given config.Provider.
func NewContentSpec(cfg config.Provider) (*ContentSpec, error) {
bf := newBlackfriday(cfg.GetStringMap("blackfriday"))
spec := &ContentSpec{
BlackFriday: bf,
footnoteAnchorPrefix: cfg.GetString("footnoteAnchorPrefix"),
footnoteReturnLinkContents: cfg.GetString("footnoteReturnLinkContents"),
summaryLength: cfg.GetInt("summaryLength"),
BuildFuture: cfg.GetBool("buildFuture"),
BuildExpired: cfg.GetBool("buildExpired"),
BuildDrafts: cfg.GetBool("buildDrafts"),
cfg: cfg,
}
// Highlighting setup
options, err := parseDefaultPygmentsOpts(cfg)
if err != nil {
return nil, err
}
spec.defatultPygmentsOpts = options
// Use the Pygmentize on path if present
useClassic := false
h := newHiglighters(spec)
if cfg.GetBool("pygmentsUseClassic") {
if !hasPygments() {
jww.WARN.Println("Highlighting with pygmentsUseClassic set requires Pygments to be installed and in the path")
} else {
useClassic = true
}
}
if useClassic {
spec.Highlight = h.pygmentsHighlight
} else {
spec.Highlight = h.chromaHighlight
}
return spec, nil
}
// BlackFriday holds configuration values for BlackFriday rendering.
type BlackFriday struct {
Smartypants bool
SmartypantsQuotesNBSP bool
AngledQuotes bool
Fractions bool
HrefTargetBlank bool
NofollowLinks bool
NoreferrerLinks bool
SmartDashes bool
LatexDashes bool
TaskLists bool
PlainIDAnchors bool
Extensions []string
ExtensionsMask []string
}
// NewBlackfriday creates a new Blackfriday filled with site config or some sane defaults.
func newBlackfriday(config map[string]interface{}) *BlackFriday {
defaultParam := map[string]interface{}{
"smartypants": true,
"angledQuotes": false,
"smartypantsQuotesNBSP": false,
"fractions": true,
"hrefTargetBlank": false,
"nofollowLinks": false,
"noreferrerLinks": false,
"smartDashes": true,
"latexDashes": true,
"plainIDAnchors": true,
"taskLists": true,
}
maps.ToLower(defaultParam)
siteConfig := make(map[string]interface{})
for k, v := range defaultParam {
siteConfig[k] = v
}
if config != nil {
for k, v := range config {
siteConfig[k] = v
}
}
combinedConfig := &BlackFriday{}
if err := mapstructure.Decode(siteConfig, combinedConfig); err != nil {
jww.FATAL.Printf("Failed to get site rendering config\n%s", err.Error())
}
return combinedConfig
}
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 stripHTMLReplacer = strings.NewReplacer("\n", " ", "</p>", "\n", "<br>", "\n", "<br />", "\n")
var mmarkExtensionMap = map[string]int{
"tables": mmark.EXTENSION_TABLES,
"fencedCode": mmark.EXTENSION_FENCED_CODE,
"autolink": mmark.EXTENSION_AUTOLINK,
"laxHtmlBlocks": mmark.EXTENSION_LAX_HTML_BLOCKS,
"spaceHeaders": mmark.EXTENSION_SPACE_HEADERS,
"hardLineBreak": mmark.EXTENSION_HARD_LINE_BREAK,
"footnotes": mmark.EXTENSION_FOOTNOTES,
"noEmptyLineBeforeBlock": mmark.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK,
"headerIds": mmark.EXTENSION_HEADER_IDS,
"autoHeaderIds": mmark.EXTENSION_AUTO_HEADER_IDS,
}
// StripHTML accepts a string, strips out all HTML tags and returns it.
func StripHTML(s string) string {
// Shortcut strings with no tags in them
if !strings.ContainsAny(s, "<>") {
return s
}
s = stripHTMLReplacer.Replace(s)
// Walk through the string removing all tags
b := bp.GetBuffer()
defer bp.PutBuffer(b)
var inTag, isSpace, wasSpace bool
for _, r := range s {
if !inTag {
isSpace = false
}
switch {
case r == '<':
inTag = true
case r == '>':
inTag = false
case unicode.IsSpace(r):
isSpace = true
fallthrough
default:
if !inTag && (!isSpace || (isSpace && !wasSpace)) {
b.WriteRune(r)
}
}
wasSpace = isSpace
}
return b.String()
}
// stripEmptyNav strips out empty <nav> tags from content.
func stripEmptyNav(in []byte) []byte {
return bytes.Replace(in, []byte("<nav>\n</nav>\n\n"), []byte(``), -1)
}
// BytesToHTML converts bytes to type template.HTML.
func BytesToHTML(b []byte) template.HTML {
return template.HTML(string(b))
}
// getHTMLRenderer creates a new Blackfriday HTML Renderer with the given configuration.
func (c *ContentSpec) getHTMLRenderer(defaultFlags int, ctx *RenderingContext) blackfriday.Renderer {
renderParameters := blackfriday.HtmlRendererParameters{
FootnoteAnchorPrefix: c.footnoteAnchorPrefix,
FootnoteReturnLinkContents: c.footnoteReturnLinkContents,
}
b := len(ctx.DocumentID) != 0
if ctx.Config == nil {
panic(fmt.Sprintf("RenderingContext of %q doesn't have a config", ctx.DocumentID))
}
if b && !ctx.Config.PlainIDAnchors {
renderParameters.FootnoteAnchorPrefix = ctx.DocumentID + ":" + renderParameters.FootnoteAnchorPrefix
renderParameters.HeaderIDSuffix = ":" + ctx.DocumentID
}
htmlFlags := defaultFlags
htmlFlags |= blackfriday.HTML_USE_XHTML
htmlFlags |= blackfriday.HTML_FOOTNOTE_RETURN_LINKS
if ctx.Config.Smartypants {
htmlFlags |= blackfriday.HTML_USE_SMARTYPANTS
}
if ctx.Config.SmartypantsQuotesNBSP {
htmlFlags |= blackfriday.HTML_SMARTYPANTS_QUOTES_NBSP
}
if ctx.Config.AngledQuotes {
htmlFlags |= blackfriday.HTML_SMARTYPANTS_ANGLED_QUOTES
}
if ctx.Config.Fractions {
htmlFlags |= blackfriday.HTML_SMARTYPANTS_FRACTIONS
}
if ctx.Config.HrefTargetBlank {
htmlFlags |= blackfriday.HTML_HREF_TARGET_BLANK
}
if ctx.Config.NofollowLinks {
htmlFlags |= blackfriday.HTML_NOFOLLOW_LINKS
}
if ctx.Config.NoreferrerLinks {
htmlFlags |= blackfriday.HTML_NOREFERRER_LINKS
}
if ctx.Config.SmartDashes {
htmlFlags |= blackfriday.HTML_SMARTYPANTS_DASHES
}
if ctx.Config.LatexDashes {
htmlFlags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
}
return &HugoHTMLRenderer{
cs: c,
RenderingContext: ctx,
Renderer: blackfriday.HtmlRendererWithParameters(htmlFlags, "", "", renderParameters),
}
}
func getMarkdownExtensions(ctx *RenderingContext) 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
if ctx.Config == nil {
panic(fmt.Sprintf("RenderingContext of %q doesn't have a config", ctx.DocumentID))
}
for _, extension := range ctx.Config.Extensions {
if flag, ok := blackfridayExtensionMap[extension]; ok {
flags |= flag
}
}
for _, extension := range ctx.Config.ExtensionsMask {
if flag, ok := blackfridayExtensionMap[extension]; ok {
flags &= ^flag
}
}
return flags
}
func (c ContentSpec) markdownRender(ctx *RenderingContext) []byte {
if ctx.RenderTOC {
return blackfriday.Markdown(ctx.Content,
c.getHTMLRenderer(blackfriday.HTML_TOC, ctx),
getMarkdownExtensions(ctx))
}
return blackfriday.Markdown(ctx.Content, c.getHTMLRenderer(0, ctx),
getMarkdownExtensions(ctx))
}
// getMmarkHTMLRenderer creates a new mmark HTML Renderer with the given configuration.
func (c *ContentSpec) getMmarkHTMLRenderer(defaultFlags int, ctx *RenderingContext) mmark.Renderer {
renderParameters := mmark.HtmlRendererParameters{
FootnoteAnchorPrefix: c.footnoteAnchorPrefix,
FootnoteReturnLinkContents: c.footnoteReturnLinkContents,
}
b := len(ctx.DocumentID) != 0
if ctx.Config == nil {
panic(fmt.Sprintf("RenderingContext of %q doesn't have a config", ctx.DocumentID))
}
if b && !ctx.Config.PlainIDAnchors {
renderParameters.FootnoteAnchorPrefix = ctx.DocumentID + ":" + renderParameters.FootnoteAnchorPrefix
// renderParameters.HeaderIDSuffix = ":" + ctx.DocumentId
}
htmlFlags := defaultFlags
htmlFlags |= mmark.HTML_FOOTNOTE_RETURN_LINKS
return &HugoMmarkHTMLRenderer{
cs: c,
Renderer: mmark.HtmlRendererWithParameters(htmlFlags, "", "", renderParameters),
Cfg: c.cfg,
}
}
func getMmarkExtensions(ctx *RenderingContext) int {
flags := 0
flags |= mmark.EXTENSION_TABLES
flags |= mmark.EXTENSION_FENCED_CODE
flags |= mmark.EXTENSION_AUTOLINK
flags |= mmark.EXTENSION_SPACE_HEADERS
flags |= mmark.EXTENSION_CITATION
flags |= mmark.EXTENSION_TITLEBLOCK_TOML
flags |= mmark.EXTENSION_HEADER_IDS
flags |= mmark.EXTENSION_AUTO_HEADER_IDS
flags |= mmark.EXTENSION_UNIQUE_HEADER_IDS
flags |= mmark.EXTENSION_FOOTNOTES
flags |= mmark.EXTENSION_SHORT_REF
flags |= mmark.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK
flags |= mmark.EXTENSION_INCLUDE
if ctx.Config == nil {
panic(fmt.Sprintf("RenderingContext of %q doesn't have a config", ctx.DocumentID))
}
for _, extension := range ctx.Config.Extensions {
if flag, ok := mmarkExtensionMap[extension]; ok {
flags |= flag
}
}
return flags
}
func (c ContentSpec) mmarkRender(ctx *RenderingContext) []byte {
return mmark.Parse(ctx.Content, c.getMmarkHTMLRenderer(0, ctx),
getMmarkExtensions(ctx)).Bytes()
}
// ExtractTOC extracts Table of Contents from content.
func ExtractTOC(content []byte) (newcontent []byte, toc []byte) {
if !bytes.Contains(content, []byte("<nav>")) {
return content, nil
}
origContent := make([]byte, len(content))
copy(origContent, content)
first := []byte(`<nav>
<ul>`)
last := []byte(`</ul>
</nav>`)
replacement := []byte(`<nav id="TableOfContents">
<ul>`)
startOfTOC := bytes.Index(content, first)
peekEnd := len(content)
if peekEnd > 70+startOfTOC {
peekEnd = 70 + startOfTOC
}
if startOfTOC < 0 {
return stripEmptyNav(content), toc
}
// Need to peek ahead to see if this nav element is actually the right one.
correctNav := bytes.Index(content[startOfTOC:peekEnd], []byte(`<li><a href="#`))
if correctNav < 0 { // no match found
return content, toc
}
lengthOfTOC := bytes.Index(content[startOfTOC:], last) + len(last)
endOfTOC := startOfTOC + lengthOfTOC
newcontent = append(content[:startOfTOC], content[endOfTOC:]...)
toc = append(replacement, origContent[startOfTOC+len(first):endOfTOC]...)
return
}
// RenderingContext holds contextual information, like content and configuration,
// for a given content rendering.
// By creating you must set the Config, otherwise it will panic.
type RenderingContext struct {
Content []byte
PageFmt string
DocumentID string
DocumentName string
Config *BlackFriday
RenderTOC bool
Cfg config.Provider
}
// RenderBytes renders a []byte.
func (c ContentSpec) RenderBytes(ctx *RenderingContext) []byte {
switch ctx.PageFmt {
default:
return c.markdownRender(ctx)
case "markdown":
return c.markdownRender(ctx)
case "asciidoc":
return getAsciidocContent(ctx)
case "mmark":
return c.mmarkRender(ctx)
case "rst":
return getRstContent(ctx)
case "org":
return orgRender(ctx, c)
case "pandoc":
return getPandocContent(ctx)
}
}
// TotalWords counts instance of one or more consecutive white space
// characters, as defined by unicode.IsSpace, in s.
// This is a cheaper way of word counting than the obvious len(strings.Fields(s)).
func TotalWords(s string) int {
n := 0
inWord := false
for _, r := range s {
wasInWord := inWord
inWord = !unicode.IsSpace(r)
if inWord && !wasInWord {
n++
}
}
return n
}
// Old implementation only kept for benchmark comparison.
// TODO(bep) remove
func totalWordsOld(s string) int {
return len(strings.Fields(s))
}
// TruncateWordsByRune truncates words by runes.
func (c *ContentSpec) TruncateWordsByRune(in []string) (string, bool) {
words := make([]string, len(in))
copy(words, in)
count := 0
for index, word := range words {
if count >= c.summaryLength {
return strings.Join(words[:index], " "), true
}
runeCount := utf8.RuneCountInString(word)
if len(word) == runeCount {
count++
} else if count+runeCount < c.summaryLength {
count += runeCount
} else {
for ri := range word {
if count >= c.summaryLength {
truncatedWords := append(words[:index], word[:ri])
return strings.Join(truncatedWords, " "), true
}
count++
}
}
}
return strings.Join(words, " "), false
}
// TruncateWordsToWholeSentence takes content and truncates to whole sentence
// limited by max number of words. It also returns whether it is truncated.
func (c *ContentSpec) TruncateWordsToWholeSentence(s string) (string, bool) {
var (
wordCount = 0
lastWordIndex = -1
)
for i, r := range s {
if unicode.IsSpace(r) {
wordCount++
lastWordIndex = i
if wordCount >= c.summaryLength {
break
}
}
}
if lastWordIndex == -1 {
return s, false
}
endIndex := -1
for j, r := range s[lastWordIndex:] {
if isEndOfSentence(r) {
endIndex = j + lastWordIndex + utf8.RuneLen(r)
break
}
}
if endIndex == -1 {
return s, false
}
return strings.TrimSpace(s[:endIndex]), endIndex < len(s)
}
func isEndOfSentence(r rune) bool {
return r == '.' || r == '?' || r == '!' || r == '"' || r == '\n'
}
// Kept only for benchmark.
func (c *ContentSpec) truncateWordsToWholeSentenceOld(content string) (string, bool) {
words := strings.Fields(content)
if c.summaryLength >= len(words) {
return strings.Join(words, " "), false
}
for counter, word := range words[c.summaryLength:] {
if strings.HasSuffix(word, ".") ||
strings.HasSuffix(word, "?") ||
strings.HasSuffix(word, ".\"") ||
strings.HasSuffix(word, "!") {
upper := c.summaryLength + counter + 1
return strings.Join(words[:upper], " "), (upper < len(words))
}
}
return strings.Join(words[:c.summaryLength], " "), true
}
func getAsciidocExecPath() string {
path, err := exec.LookPath("asciidoc")
if err != nil {
return ""
}
return path
}
func getAsciidoctorExecPath() string {
path, err := exec.LookPath("asciidoctor")
if err != nil {
return ""
}
return path
}
// HasAsciidoc returns whether Asciidoc or Asciidoctor is installed on this computer.
func HasAsciidoc() bool {
return (getAsciidoctorExecPath() != "" ||
getAsciidocExecPath() != "")
}
// getAsciidocContent calls asciidoctor or asciidoc as an external helper
// to convert AsciiDoc content to HTML.
func getAsciidocContent(ctx *RenderingContext) []byte {
var isAsciidoctor bool
path := getAsciidoctorExecPath()
if path == "" {
path = getAsciidocExecPath()
if path == "" {
jww.ERROR.Println("asciidoctor / asciidoc not found in $PATH: Please install.\n",
" Leaving AsciiDoc content unrendered.")
return ctx.Content
}
} else {
isAsciidoctor = true
}
jww.INFO.Println("Rendering", ctx.DocumentName, "with", path, "...")
args := []string{"--no-header-footer", "--safe"}
if isAsciidoctor {
// asciidoctor-specific arg to show stack traces on errors
args = append(args, "--trace")
}
args = append(args, "-")
return externallyRenderContent(ctx, path, args)
}
// HasRst returns whether rst2html is installed on this computer.
func HasRst() bool {
return getRstExecPath() != ""
}
func getRstExecPath() string {
path, err := exec.LookPath("rst2html")
if err != nil {
path, err = exec.LookPath("rst2html.py")
if err != nil {
return ""
}
}
return path
}
func getPythonExecPath() string {
path, err := exec.LookPath("python")
if err != nil {
path, err = exec.LookPath("python.exe")
if err != nil {
return ""
}
}
return path
}
// getRstContent calls the Python script rst2html as an external helper
// to convert reStructuredText content to HTML.
func getRstContent(ctx *RenderingContext) []byte {
python := getPythonExecPath()
path := getRstExecPath()
if path == "" {
jww.ERROR.Println("rst2html / rst2html.py not found in $PATH: Please install.\n",
" Leaving reStructuredText content unrendered.")
return ctx.Content
}
jww.INFO.Println("Rendering", ctx.DocumentName, "with", path, "...")
args := []string{path, "--leave-comments", "--initial-header-level=2"}
result := externallyRenderContent(ctx, python, args)
// TODO(bep) check if rst2html has a body only option.
bodyStart := bytes.Index(result, []byte("<body>\n"))
if bodyStart < 0 {
bodyStart = -7 //compensate for length
}
bodyEnd := bytes.Index(result, []byte("\n</body>"))
if bodyEnd < 0 || bodyEnd >= len(result) {
bodyEnd = len(result) - 1
if bodyEnd < 0 {
bodyEnd = 0
}
}
return result[bodyStart+7 : bodyEnd]
}
// getPandocContent calls pandoc as an external helper to convert pandoc markdown to HTML.
func getPandocContent(ctx *RenderingContext) []byte {
path, err := exec.LookPath("pandoc")
if err != nil {
jww.ERROR.Println("pandoc not found in $PATH: Please install.\n",
" Leaving pandoc content unrendered.")
return ctx.Content
}
args := []string{"--mathjax"}
return externallyRenderContent(ctx, path, args)
}
func orgRender(ctx *RenderingContext, c ContentSpec) []byte {
content := ctx.Content
cleanContent := bytes.Replace(content, []byte("# more"), []byte(""), 1)
return goorgeous.Org(cleanContent,
c.getHTMLRenderer(blackfriday.HTML_TOC, ctx))
}
func externallyRenderContent(ctx *RenderingContext, path string, args []string) []byte {
content := ctx.Content
cleanContent := bytes.Replace(content, SummaryDivider, []byte(""), 1)
cmd := exec.Command(path, args...)
cmd.Stdin = bytes.NewReader(cleanContent)
var out, cmderr bytes.Buffer
cmd.Stdout = &out
cmd.Stderr = &cmderr
err := cmd.Run()
// Most external helpers exit w/ non-zero exit code only if severe, i.e.
// halting errors occurred. -> log stderr output regardless of state of err
for _, item := range strings.Split(string(cmderr.Bytes()), "\n") {
item := strings.TrimSpace(item)
if item != "" {
jww.ERROR.Printf("%s: %s", ctx.DocumentName, item)
}
}
if err != nil {
jww.ERROR.Printf("%s rendering %s: %v", path, ctx.DocumentName, err)
}
return normalizeExternalHelperLineFeeds(out.Bytes())
}