ref: 195bd1243b350e7a7814e0c893d17c3c408039c7
dir: /markup/asciidocext/convert.go/
// Copyright 2020 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 asciidocext converts Asciidoc to HTML using Asciidoc or Asciidoctor
// external binaries. The `asciidoc` module is reserved for a future golang
// implementation.
package asciidocext
import (
"bytes"
"os/exec"
"path/filepath"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/markup/asciidocext/asciidocext_config"
"github.com/gohugoio/hugo/markup/converter"
"github.com/gohugoio/hugo/markup/internal"
"github.com/gohugoio/hugo/markup/tableofcontents"
"golang.org/x/net/html"
)
/* ToDo: RelPermalink patch for svg posts not working*/
type pageSubset interface {
RelPermalink() string
}
// Provider is the package entry point.
var Provider converter.ProviderProvider = provider{}
type provider struct{}
func (p provider) New(cfg converter.ProviderConfig) (converter.Provider, error) {
return converter.NewProvider("asciidocext", func(ctx converter.DocumentContext) (converter.Converter, error) {
return &asciidocConverter{
ctx: ctx,
cfg: cfg,
}, nil
}), nil
}
type asciidocResult struct {
converter.Result
toc tableofcontents.Root
}
func (r asciidocResult) TableOfContents() tableofcontents.Root {
return r.toc
}
type asciidocConverter struct {
ctx converter.DocumentContext
cfg converter.ProviderConfig
}
func (a *asciidocConverter) Convert(ctx converter.RenderContext) (converter.Result, error) {
content, toc, err := extractTOC(a.getAsciidocContent(ctx.Src, a.ctx))
if err != nil {
return nil, err
}
return asciidocResult{
Result: converter.Bytes(content),
toc: toc,
}, nil
}
func (a *asciidocConverter) Supports(_ identity.Identity) bool {
return false
}
// getAsciidocContent calls asciidoctor or asciidoc as an external helper
// to convert AsciiDoc content to HTML.
func (a *asciidocConverter) getAsciidocContent(src []byte, ctx converter.DocumentContext) []byte {
path := getAsciidoctorExecPath()
if path == "" {
a.cfg.Logger.ERROR.Println("asciidoctor / asciidoc not found in $PATH: Please install.\n",
" Leaving AsciiDoc content unrendered.")
return src
}
args := a.parseArgs(ctx)
args = append(args, "-")
a.cfg.Logger.INFO.Println("Rendering", ctx.DocumentName, "with", path, "using asciidoctor args", args, "...")
return internal.ExternallyRenderContent(a.cfg, ctx, src, path, args)
}
func (a *asciidocConverter) parseArgs(ctx converter.DocumentContext) []string {
var cfg = a.cfg.MarkupConfig.AsciidocExt
args := []string{}
args = a.appendArg(args, "-b", cfg.Backend, asciidocext_config.CliDefault.Backend, asciidocext_config.AllowedBackend)
for _, extension := range cfg.Extensions {
if !asciidocext_config.AllowedExtensions[extension] {
a.cfg.Logger.ERROR.Println("Unsupported asciidoctor extension was passed in. Extension `" + extension + "` ignored.")
continue
}
args = append(args, "-r", extension)
}
for attributeKey, attributeValue := range cfg.Attributes {
if asciidocext_config.DisallowedAttributes[attributeKey] {
a.cfg.Logger.ERROR.Println("Unsupported asciidoctor attribute was passed in. Attribute `" + attributeKey + "` ignored.")
continue
}
args = append(args, "-a", attributeKey+"="+attributeValue)
}
if cfg.WorkingFolderCurrent {
contentDir := filepath.Dir(ctx.Filename)
sourceDir := a.cfg.Cfg.GetString("source")
destinationDir := a.cfg.Cfg.GetString("destination")
if destinationDir == "" {
a.cfg.Logger.ERROR.Println("markup.asciidocext.workingFolderCurrent requires hugo command option --destination to be set")
}
if !filepath.IsAbs(destinationDir) && sourceDir != "" {
destinationDir = filepath.Join(sourceDir, destinationDir)
}
var outDir string
var err error
file := filepath.Base(ctx.Filename)
if a.cfg.Cfg.GetBool("uglyUrls") || file == "_index.adoc" || file == "index.adoc" {
outDir, err = filepath.Abs(filepath.Dir(filepath.Join(destinationDir, ctx.DocumentName)))
} else {
postDir := ""
page, ok := ctx.Document.(pageSubset)
if ok {
postDir = filepath.Base(page.RelPermalink())
} else {
a.cfg.Logger.ERROR.Println("unable to cast interface to pageSubset")
}
outDir, err = filepath.Abs(filepath.Join(destinationDir, filepath.Dir(ctx.DocumentName), postDir))
}
if err != nil {
a.cfg.Logger.ERROR.Println("asciidoctor outDir: ", err)
}
args = append(args, "--base-dir", contentDir, "-a", "outdir="+outDir)
}
if cfg.NoHeaderOrFooter {
args = append(args, "--no-header-footer")
} else {
a.cfg.Logger.WARN.Println("asciidoctor parameter NoHeaderOrFooter is expected for correct html rendering")
}
if cfg.SectionNumbers {
args = append(args, "--section-numbers")
}
if cfg.Verbose {
args = append(args, "--verbose")
}
if cfg.Trace {
args = append(args, "--trace")
}
args = a.appendArg(args, "--failure-level", cfg.FailureLevel, asciidocext_config.CliDefault.FailureLevel, asciidocext_config.AllowedFailureLevel)
args = a.appendArg(args, "--safe-mode", cfg.SafeMode, asciidocext_config.CliDefault.SafeMode, asciidocext_config.AllowedSafeMode)
return args
}
func (a *asciidocConverter) appendArg(args []string, option, value, defaultValue string, allowedValues map[string]bool) []string {
if value != defaultValue {
if allowedValues[value] {
args = append(args, option, value)
} else {
a.cfg.Logger.ERROR.Println("Unsupported asciidoctor value `" + value + "` for option " + option + " was passed in and will be ignored.")
}
}
return args
}
func getAsciidoctorExecPath() string {
path, err := exec.LookPath("asciidoctor")
if err != nil {
return ""
}
return path
}
// extractTOC extracts the toc from the given src html.
// It returns the html without the TOC, and the TOC data
func extractTOC(src []byte) ([]byte, tableofcontents.Root, error) {
var buf bytes.Buffer
buf.Write(src)
node, err := html.Parse(&buf)
if err != nil {
return nil, tableofcontents.Root{}, err
}
var (
f func(*html.Node) bool
toc tableofcontents.Root
toVisit []*html.Node
)
f = func(n *html.Node) bool {
if n.Type == html.ElementNode && n.Data == "div" {
for _, a := range n.Attr {
if a.Key == "id" && a.Val == "toc" {
toc, err = parseTOC(n)
if err != nil {
return false
}
n.Parent.RemoveChild(n)
return true
}
}
}
if n.FirstChild != nil {
toVisit = append(toVisit, n.FirstChild)
}
if n.NextSibling != nil {
if ok := f(n.NextSibling); ok {
return true
}
}
for len(toVisit) > 0 {
nv := toVisit[0]
toVisit = toVisit[1:]
if ok := f(nv); ok {
return true
}
}
return false
}
f(node)
if err != nil {
return nil, tableofcontents.Root{}, err
}
buf.Reset()
err = html.Render(&buf, node)
if err != nil {
return nil, tableofcontents.Root{}, err
}
// ltrim <html><head></head><body> and rtrim </body></html> which are added by html.Render
res := buf.Bytes()[25:]
res = res[:len(res)-14]
return res, toc, nil
}
// parseTOC returns a TOC root from the given toc Node
func parseTOC(doc *html.Node) (tableofcontents.Root, error) {
var (
toc tableofcontents.Root
f func(*html.Node, int, int)
)
f = func(n *html.Node, parent, level int) {
if n.Type == html.ElementNode {
switch n.Data {
case "ul":
if level == 0 {
parent += 1
}
level += 1
f(n.FirstChild, parent, level)
case "li":
for c := n.FirstChild; c != nil; c = c.NextSibling {
if c.Type != html.ElementNode || c.Data != "a" {
continue
}
var href string
for _, a := range c.Attr {
if a.Key == "href" {
href = a.Val[1:]
break
}
}
for d := c.FirstChild; d != nil; d = d.NextSibling {
if d.Type == html.TextNode {
toc.AddAt(tableofcontents.Header{
Text: d.Data,
ID: href,
}, parent, level)
}
}
}
f(n.FirstChild, parent, level)
}
}
if n.NextSibling != nil {
f(n.NextSibling, parent, level)
}
}
f(doc.FirstChild, 0, 0)
return toc, nil
}
// Supports returns whether Asciidoctor is installed on this computer.
func Supports() bool {
return getAsciidoctorExecPath() != ""
}