hugo/hugolib/alias.go
Bjørn Erik Pedersen dea71670c0
Add Hugo Piper with SCSS support and much more
Before this commit, you would have to use page bundles to do image processing etc. in Hugo.

This commit adds

* A new `/assets` top-level project or theme dir (configurable via `assetDir`)
* A new template func, `resources.Get` which can be used to "get a resource" that can be further processed.

This means that you can now do this in your templates (or shortcodes):

```bash
{{ $sunset := (resources.Get "images/sunset.jpg").Fill "300x200" }}
```

This also adds a new `extended` build tag that enables powerful SCSS/SASS support with source maps. To compile this from source, you will also need a C compiler installed:

```
HUGO_BUILD_TAGS=extended mage install
```

Note that you can use output of the SCSS processing later in a non-SCSSS-enabled Hugo.

The `SCSS` processor is a _Resource transformation step_ and it can be chained with the many others in a pipeline:

```bash
{{ $css := resources.Get "styles.scss" | resources.ToCSS | resources.PostCSS | resources.Minify | resources.Fingerprint }}
<link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen">
```

The transformation funcs above have aliases, so it can be shortened to:

```bash
{{ $css := resources.Get "styles.scss" | toCSS | postCSS | minify | fingerprint }}
<link rel="stylesheet" href="{{ $styles.RelPermalink }}" integrity="{{ $styles.Data.Digest }}" media="screen">
```

A quick tip would be to avoid the fingerprinting part, and possibly also the not-superfast `postCSS` when you're doing development, as it allows Hugo to be smarter about the rebuilding.

Documentation will follow, but have a look at the demo repo in https://github.com/bep/hugo-sass-test

New functions to create `Resource` objects:

* `resources.Get` (see above)
* `resources.FromString`: Create a Resource from a string.

New `Resource` transformation funcs:

* `resources.ToCSS`: Compile `SCSS` or `SASS` into `CSS`.
* `resources.PostCSS`: Process your CSS with PostCSS. Config file support (project or theme or passed as an option).
* `resources.Minify`: Currently supports `css`, `js`, `json`, `html`, `svg`, `xml`.
* `resources.Fingerprint`: Creates a fingerprinted version of the given Resource with Subresource Integrity..
* `resources.Concat`: Concatenates a list of Resource objects. Think of this as a poor man's bundler.
* `resources.ExecuteAsTemplate`: Parses and executes the given Resource and data context (e.g. .Site) as a Go template.

Fixes #4381
Fixes #4903
Fixes #4858
2018-07-06 11:46:12 +02:00

184 lines
5.7 KiB
Go

// Copyright 2017 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 hugolib
import (
"bytes"
"fmt"
"html/template"
"io"
"path/filepath"
"runtime"
"strings"
"github.com/gohugoio/hugo/tpl"
jww "github.com/spf13/jwalterweatherman"
"github.com/gohugoio/hugo/helpers"
)
const (
alias = "<!DOCTYPE html><html><head><title>{{ .Permalink }}</title><link rel=\"canonical\" href=\"{{ .Permalink }}\"/><meta name=\"robots\" content=\"noindex\"><meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" /><meta http-equiv=\"refresh\" content=\"0; url={{ .Permalink }}\" /></head></html>"
aliasXHtml = "<!DOCTYPE html><html xmlns=\"http://www.w3.org/1999/xhtml\"><head><title>{{ .Permalink }}</title><link rel=\"canonical\" href=\"{{ .Permalink }}\"/><meta name=\"robots\" content=\"noindex\"><meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" /><meta http-equiv=\"refresh\" content=\"0; url={{ .Permalink }}\" /></head></html>"
)
var defaultAliasTemplates *template.Template
func init() {
//TODO(bep) consolidate
defaultAliasTemplates = template.New("")
template.Must(defaultAliasTemplates.New("alias").Parse(alias))
template.Must(defaultAliasTemplates.New("alias-xhtml").Parse(aliasXHtml))
}
type aliasHandler struct {
t tpl.TemplateFinder
log *jww.Notepad
allowRoot bool
}
func newAliasHandler(t tpl.TemplateFinder, l *jww.Notepad, allowRoot bool) aliasHandler {
return aliasHandler{t, l, allowRoot}
}
func (a aliasHandler) renderAlias(isXHTML bool, permalink string, page *Page) (io.Reader, error) {
t := "alias"
if isXHTML {
t = "alias-xhtml"
}
var templ tpl.Template
var found bool
if a.t != nil {
templ, found = a.t.Lookup("alias.html")
}
if !found {
def := defaultAliasTemplates.Lookup(t)
if def != nil {
templ = &tpl.TemplateAdapter{Template: def}
}
}
data := struct {
Permalink string
Page *Page
}{
permalink,
page,
}
buffer := new(bytes.Buffer)
err := templ.Execute(buffer, data)
if err != nil {
return nil, err
}
return buffer, nil
}
func (s *Site) writeDestAlias(path, permalink string, p *Page) (err error) {
return s.publishDestAlias(false, path, permalink, p)
}
func (s *Site) publishDestAlias(allowRoot bool, path, permalink string, p *Page) (err error) {
handler := newAliasHandler(s.Tmpl, s.Log, allowRoot)
isXHTML := strings.HasSuffix(path, ".xhtml")
s.Log.DEBUG.Println("creating alias:", path, "redirecting to", permalink)
targetPath, err := handler.targetPathAlias(path)
if err != nil {
return err
}
aliasContent, err := handler.renderAlias(isXHTML, permalink, p)
if err != nil {
return err
}
return s.publish(&s.PathSpec.ProcessingStats.Aliases, targetPath, aliasContent)
}
func (a aliasHandler) targetPathAlias(src string) (string, error) {
originalAlias := src
if len(src) <= 0 {
return "", fmt.Errorf("Alias \"\" is an empty string")
}
alias := filepath.Clean(src)
components := strings.Split(alias, helpers.FilePathSeparator)
if !a.allowRoot && alias == helpers.FilePathSeparator {
return "", fmt.Errorf("Alias \"%s\" resolves to website root directory", originalAlias)
}
// Validate against directory traversal
if components[0] == ".." {
return "", fmt.Errorf("Alias \"%s\" traverses outside the website root directory", originalAlias)
}
// Handle Windows file and directory naming restrictions
// See "Naming Files, Paths, and Namespaces" on MSDN
// https://msdn.microsoft.com/en-us/library/aa365247%28v=VS.85%29.aspx?f=255&MSPPError=-2147217396
msgs := []string{}
reservedNames := []string{"CON", "PRN", "AUX", "NUL", "COM0", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT0", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9"}
if strings.ContainsAny(alias, ":*?\"<>|") {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains invalid characters on Windows: : * ? \" < > |", originalAlias))
}
for _, ch := range alias {
if ch < ' ' {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains ASCII control code (0x00 to 0x1F), invalid on Windows: : * ? \" < > |", originalAlias))
continue
}
}
for _, comp := range components {
if strings.HasSuffix(comp, " ") || strings.HasSuffix(comp, ".") {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains component with a trailing space or period, problematic on Windows", originalAlias))
}
for _, r := range reservedNames {
if comp == r {
msgs = append(msgs, fmt.Sprintf("Alias \"%s\" contains component with reserved name \"%s\" on Windows", originalAlias, r))
}
}
}
if len(msgs) > 0 {
if runtime.GOOS == "windows" {
for _, m := range msgs {
a.log.ERROR.Println(m)
}
return "", fmt.Errorf("Cannot create \"%s\": Windows filename restriction", originalAlias)
}
for _, m := range msgs {
a.log.WARN.Println(m)
}
}
// Add the final touch
alias = strings.TrimPrefix(alias, helpers.FilePathSeparator)
if strings.HasSuffix(alias, helpers.FilePathSeparator) {
alias = alias + "index.html"
} else if !strings.HasSuffix(alias, ".html") {
alias = alias + helpers.FilePathSeparator + "index.html"
}
if originalAlias != alias {
a.log.INFO.Printf("Alias \"%s\" translated to \"%s\"\n", originalAlias, alias)
}
return alias, nil
}