hugo/commands/static_syncer.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

130 lines
4.4 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 commands
import (
"os"
"path/filepath"
"github.com/gohugoio/hugo/hugolib/filesystems"
"github.com/fsnotify/fsnotify"
"github.com/gohugoio/hugo/helpers"
"github.com/spf13/fsync"
)
type staticSyncer struct {
c *commandeer
}
func newStaticSyncer(c *commandeer) (*staticSyncer, error) {
return &staticSyncer{c: c}, nil
}
func (s *staticSyncer) isStatic(filename string) bool {
return s.c.hugo.BaseFs.SourceFilesystems.IsStatic(filename)
}
func (s *staticSyncer) syncsStaticEvents(staticEvents []fsnotify.Event) error {
c := s.c
syncFn := func(sourceFs *filesystems.SourceFilesystem) (uint64, error) {
publishDir := c.hugo.PathSpec.PublishDir
// If root, remove the second '/'
if publishDir == "//" {
publishDir = helpers.FilePathSeparator
}
if sourceFs.PublishFolder != "" {
publishDir = filepath.Join(publishDir, sourceFs.PublishFolder)
}
syncer := fsync.NewSyncer()
syncer.NoTimes = c.Cfg.GetBool("noTimes")
syncer.NoChmod = c.Cfg.GetBool("noChmod")
syncer.SrcFs = sourceFs.Fs
syncer.DestFs = c.Fs.Destination
// prevent spamming the log on changes
logger := helpers.NewDistinctFeedbackLogger()
for _, ev := range staticEvents {
// Due to our approach of layering both directories and the content's rendered output
// into one we can't accurately remove a file not in one of the source directories.
// If a file is in the local static dir and also in the theme static dir and we remove
// it from one of those locations we expect it to still exist in the destination
//
// If Hugo generates a file (from the content dir) over a static file
// the content generated file should take precedence.
//
// Because we are now watching and handling individual events it is possible that a static
// event that occupies the same path as a content generated file will take precedence
// until a regeneration of the content takes places.
//
// Hugo assumes that these cases are very rare and will permit this bad behavior
// The alternative is to track every single file and which pipeline rendered it
// and then to handle conflict resolution on every event.
fromPath := ev.Name
relPath := sourceFs.MakePathRelative(fromPath)
if relPath == "" {
// Not member of this virtual host.
continue
}
// Remove || rename is harder and will require an assumption.
// Hugo takes the following approach:
// If the static file exists in any of the static source directories after this event
// Hugo will re-sync it.
// If it does not exist in all of the static directories Hugo will remove it.
//
// This assumes that Hugo has not generated content on top of a static file and then removed
// the source of that static file. In this case Hugo will incorrectly remove that file
// from the published directory.
if ev.Op&fsnotify.Rename == fsnotify.Rename || ev.Op&fsnotify.Remove == fsnotify.Remove {
if _, err := sourceFs.Fs.Stat(relPath); os.IsNotExist(err) {
// If file doesn't exist in any static dir, remove it
toRemove := filepath.Join(publishDir, relPath)
logger.Println("File no longer exists in static dir, removing", toRemove)
_ = c.Fs.Destination.RemoveAll(toRemove)
} else if err == nil {
// If file still exists, sync it
logger.Println("Syncing", relPath, "to", publishDir)
if err := syncer.Sync(filepath.Join(publishDir, relPath), relPath); err != nil {
c.Logger.ERROR.Println(err)
}
} else {
c.Logger.ERROR.Println(err)
}
continue
}
// For all other event operations Hugo will sync static.
logger.Println("Syncing", relPath, "to", publishDir)
if err := syncer.Sync(filepath.Join(publishDir, relPath), relPath); err != nil {
c.Logger.ERROR.Println(err)
}
}
return 0, nil
}
_, err := c.doWithPublishDirs(syncFn)
return err
}