// 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" "runtime" "github.com/gohugoio/hugo/common/hexec" "github.com/gohugoio/hugo/htesting" "github.com/gohugoio/hugo/identity" "github.com/gohugoio/hugo/markup/converter" "github.com/gohugoio/hugo/markup/internal" ) // 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.ResultRender, error) { b, err := c.getRstContent(ctx.Src, c.ctx) if err != nil { return nil, err } return converter.Bytes(b), 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, error) { logger := c.cfg.Logger binaryName, binaryPath := getRstBinaryNameAndPath() if binaryName == "" { logger.Println("rst2html / rst2html.py not found in $PATH: Please install.\n", " Leaving reStructuredText content unrendered.") return src, nil } logger.Infoln("Rendering", ctx.DocumentName, "with", binaryName, "...") var result []byte var err error // 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" { pythonBinary, _ := internal.GetPythonBinaryAndExecPath() args := []string{binaryPath, "--leave-comments", "--initial-header-level=2"} result, err = internal.ExternallyRenderContent(c.cfg, ctx, src, pythonBinary, args) } else { args := []string{"--leave-comments", "--initial-header-level=2"} result, err = internal.ExternallyRenderContent(c.cfg, ctx, src, binaryName, args) } if err != nil { return nil, err } // TODO(bep) check if rst2html has a body only option. bodyStart := bytes.Index(result, []byte("\n")) if bodyStart < 0 { bodyStart = -7 // compensate for length } bodyEnd := bytes.Index(result, []byte("\n")) if bodyEnd < 0 || bodyEnd >= len(result) { bodyEnd = len(result) - 1 if bodyEnd < 0 { bodyEnd = 0 } } return result[bodyStart+7 : bodyEnd], err } var rst2Binaries = []string{"rst2html", "rst2html.py"} func getRstBinaryNameAndPath() (string, string) { for _, candidate := range rst2Binaries { if pth := hexec.LookPath(candidate); pth != "" { return candidate, pth } } return "", "" } // Supports returns whether rst is (or should be) installed on this computer. func Supports() bool { name, _ := getRstBinaryNameAndPath() hasBin := name != "" if htesting.SupportsAll() { if !hasBin { panic("rst not installed") } return true } return hasBin }