hugo/source/fileInfo.go
Bjørn Erik Pedersen 80230f26a3
Add support for theme composition and inheritance
This commit adds support for theme composition and inheritance in Hugo.

With this, it helps thinking about a theme as a set of ordered components:

```toml
theme = ["my-shortcodes", "base-theme", "hyde"]
```

The theme definition example above in `config.toml` creates a theme with the 3 components with presedence from left to right.

So, Hugo will, for any given file, data entry etc., look first in the project, and then in `my-shortcode`, `base-theme` and lastly `hyde`.

Hugo uses two different algorithms to merge the filesystems, depending on the file type:

* For `i18n` and `data` files, Hugo merges deeply using the translation id and data key inside the files.
* For `static`, `layouts` (templates) and `archetypes` files, these are merged on file level. So the left-most file will be chosen.

The name used in the `theme` definition above must match a folder in `/your-site/themes`, e.g. `/your-site/themes/my-shortcodes`. There are  plans to improve on this and get a URL scheme so this can be resolved automatically.

Also note that a component that is part of a theme can have its own configuration file, e.g. `config.toml`. There are currently some restrictions to what a theme component can configure:

* `params` (global and per language)
* `menu` (global and per language)
* `outputformats` and `mediatypes`

The same rules apply here: The left-most param/menu etc. with the same ID will win. There are some hidden and experimental namespace support in the above, which we will work to improve in the future, but theme authors are encouraged to create their own namespaces to avoid naming conflicts.

A final note: Themes/components can also have a `theme` definition in their `config.toml` and similar, which is the "inheritance" part of this commit's title. This is currently not supported by the Hugo theme site. We will have to wait for some "auto dependency" feature to be implemented for that to happen, but this can be a powerful feature if you want to create your own theme-variant based on others.

Fixes #4460
Fixes #4450
2018-06-10 23:55:20 +02:00

246 lines
6.3 KiB
Go

// Copyright 2017-present 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 source
import (
"fmt"
"io"
"os"
"path/filepath"
"strings"
"sync"
"github.com/spf13/afero"
"github.com/gohugoio/hugo/hugofs"
"github.com/gohugoio/hugo/helpers"
)
// fileInfo implements the File interface.
var (
_ File = (*FileInfo)(nil)
_ ReadableFile = (*FileInfo)(nil)
)
type File interface {
// Filename gets the full path and filename to the file.
Filename() string
// Path gets the relative path including file name and extension.
// The directory is relative to the content root.
Path() string
// Dir gets the name of the directory that contains this file.
// The directory is relative to the content root.
Dir() string
// Extension gets the file extension, i.e "myblogpost.md" will return "md".
Extension() string
// Ext is an alias for Extension.
Ext() string // Hmm... Deprecate Extension
// Lang for this page, if `Multilingual` is enabled on your site.
Lang() string
// LogicalName is filename and extension of the file.
LogicalName() string
// Section is first directory below the content root.
// For page bundles in root, the Section will be empty.
Section() string
// BaseFileName is a filename without extension.
BaseFileName() string
// TranslationBaseName is a filename with no extension,
// not even the optional language extension part.
TranslationBaseName() string
// UniqueID is the MD5 hash of the file's path and is for most practical applications,
// Hugo content files being one of them, considered to be unique.
UniqueID() string
FileInfo() os.FileInfo
String() string
}
// A ReadableFile is a File that is readable.
type ReadableFile interface {
File
Open() (io.ReadCloser, error)
}
type FileInfo struct {
// Absolute filename to the file on disk.
filename string
sp *SourceSpec
fi os.FileInfo
// Derived from filename
ext string // Extension without any "."
lang string
name string
dir string
relDir string
relPath string
baseName string
translationBaseName string
section string
isLeafBundle bool
uniqueID string
lazyInit sync.Once
}
func (fi *FileInfo) Filename() string { return fi.filename }
func (fi *FileInfo) Path() string { return fi.relPath }
func (fi *FileInfo) Dir() string { return fi.relDir }
func (fi *FileInfo) Extension() string { return fi.Ext() }
func (fi *FileInfo) Ext() string { return fi.ext }
func (fi *FileInfo) Lang() string { return fi.lang }
func (fi *FileInfo) LogicalName() string { return fi.name }
func (fi *FileInfo) BaseFileName() string { return fi.baseName }
func (fi *FileInfo) TranslationBaseName() string { return fi.translationBaseName }
func (fi *FileInfo) Section() string {
fi.init()
return fi.section
}
func (fi *FileInfo) UniqueID() string {
fi.init()
return fi.uniqueID
}
func (fi *FileInfo) FileInfo() os.FileInfo {
return fi.fi
}
func (fi *FileInfo) String() string { return fi.BaseFileName() }
// We create a lot of these FileInfo objects, but there are parts of it used only
// in some cases that is slightly expensive to construct.
func (fi *FileInfo) init() {
fi.lazyInit.Do(func() {
relDir := strings.Trim(fi.relDir, helpers.FilePathSeparator)
parts := strings.Split(relDir, helpers.FilePathSeparator)
var section string
if (!fi.isLeafBundle && len(parts) == 1) || len(parts) > 1 {
section = parts[0]
}
fi.section = section
fi.uniqueID = helpers.MD5String(filepath.ToSlash(fi.relPath))
})
}
func (sp *SourceSpec) NewFileInfo(baseDir, filename string, isLeafBundle bool, fi os.FileInfo) *FileInfo {
var lang, translationBaseName, relPath string
if fp, ok := fi.(hugofs.FilePather); ok {
filename = fp.Filename()
baseDir = fp.BaseDir()
relPath = fp.Path()
}
if fl, ok := fi.(hugofs.LanguageAnnouncer); ok {
lang = fl.Lang()
translationBaseName = fl.TranslationBaseName()
}
dir, name := filepath.Split(filename)
if !strings.HasSuffix(dir, helpers.FilePathSeparator) {
dir = dir + helpers.FilePathSeparator
}
baseDir = strings.TrimSuffix(baseDir, helpers.FilePathSeparator)
relDir := ""
if dir != baseDir {
relDir = strings.TrimPrefix(dir, baseDir)
}
relDir = strings.TrimPrefix(relDir, helpers.FilePathSeparator)
if relPath == "" {
relPath = filepath.Join(relDir, name)
}
ext := strings.ToLower(strings.TrimPrefix(filepath.Ext(name), "."))
baseName := helpers.Filename(name)
if translationBaseName == "" {
// This is usyally provided by the filesystem. But this FileInfo is also
// created in a standalone context when doing "hugo new". This is
// an approximate implementation, which is "good enough" in that case.
fileLangExt := filepath.Ext(baseName)
translationBaseName = strings.TrimSuffix(baseName, fileLangExt)
}
f := &FileInfo{
sp: sp,
filename: filename,
fi: fi,
lang: lang,
ext: ext,
dir: dir,
relDir: relDir,
relPath: relPath,
name: name,
baseName: baseName,
translationBaseName: translationBaseName,
isLeafBundle: isLeafBundle,
}
return f
}
// Open implements ReadableFile.
func (fi *FileInfo) Open() (io.ReadCloser, error) {
f, err := fi.sp.SourceFs.Open(fi.Filename())
return f, err
}
func printFs(fs afero.Fs, path string, w io.Writer) {
if fs == nil {
return
}
afero.Walk(fs, path, func(path string, info os.FileInfo, err error) error {
if info != nil && !info.IsDir() {
s := path
if lang, ok := info.(hugofs.LanguageAnnouncer); ok {
s = s + "\t" + lang.Lang()
}
if fp, ok := info.(hugofs.FilePather); ok {
s = s + "\t" + fp.Filename()
}
fmt.Fprintln(w, " ", s)
}
return nil
})
}