// 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.ERROR.Println("rst2html / rst2html.py not found in $PATH: Please install.\n", " Leaving reStructuredText content unrendered.") return src } logger.INFO.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("\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] } 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() != "" }