ref: 718e09ed4bc538f4fccc4337f99e9eb86aea31f3
dir: /markup/rst/convert.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 rst converts content to HTML using the RST external helper.
package rst
import (
"bytes"
"os/exec"
"runtime"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/markup/internal"
"github.com/gohugoio/hugo/markup/converter"
)
// 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("rst", func(ctx converter.DocumentContext) (converter.Converter, error) {
return &rstConverter{
ctx: ctx,
cfg: cfg,
}, nil
}), nil
}
type rstConverter struct {
ctx converter.DocumentContext
cfg converter.ProviderConfig
}
func (c *rstConverter) Convert(ctx converter.RenderContext) (converter.Result, error) {
return converter.Bytes(c.getRstContent(ctx.Src, c.ctx)), nil
}
func (c *rstConverter) Supports(feature identity.Identity) bool {
return false
}
// getRstContent calls the Python script rst2html as an external helper
// to convert reStructuredText content to HTML.
func (c *rstConverter) getRstContent(src []byte, ctx converter.DocumentContext) []byte {
logger := c.cfg.Logger
path := getRstExecPath()
if path == "" {
logger.Println("rst2html / rst2html.py not found in $PATH: Please install.\n",
" Leaving reStructuredText content unrendered.")
return src
}
logger.Println("Rendering", ctx.DocumentName, "with", path, "...")
var result []byte
// certain *nix based OSs wrap executables in scripted launchers
// invoking binaries on these OSs via python interpreter causes SyntaxError
// invoke directly so that shebangs work as expected
// handle Windows manually because it doesn't do shebangs
if runtime.GOOS == "windows" {
python := internal.GetPythonExecPath()
args := []string{path, "--leave-comments", "--initial-header-level=2"}
result = internal.ExternallyRenderContent(c.cfg, ctx, src, python, args)
} else {
args := []string{"--leave-comments", "--initial-header-level=2"}
result = internal.ExternallyRenderContent(c.cfg, ctx, src, path, 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]
}
func getRstExecPath() string {
path, err := exec.LookPath("rst2html")
if err != nil {
path, err = exec.LookPath("rst2html.py")
if err != nil {
return ""
}
}
return path
}
// Supports returns whether rst is installed on this computer.
func Supports() bool {
return getRstExecPath() != ""
}