hugo/output/docshelper.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

105 lines
4.1 KiB
Go

package output
import (
"strings"
// "fmt"
"github.com/gohugoio/hugo/docshelper"
)
// This is is just some helpers used to create some JSON used in the Hugo docs.
func init() {
docsProvider := func() map[string]interface{} {
docs := make(map[string]interface{})
docs["formats"] = DefaultFormats
docs["layouts"] = createLayoutExamples()
return docs
}
docshelper.AddDocProvider("output", docsProvider)
}
func createLayoutExamples() interface{} {
type Example struct {
Example string
Kind string
OutputFormat string
Suffix string
Layouts []string `json:"Template Lookup Order"`
}
var (
basicExamples []Example
demoLayout = "demolayout"
demoType = "demotype"
)
for _, example := range []struct {
name string
d LayoutDescriptor
hasTheme bool
f Format
}{
// Taxonomy output.LayoutDescriptor={categories category taxonomy en false Type Section
{"Single page in \"posts\" section", LayoutDescriptor{Kind: "page", Type: "posts"}, false, HTMLFormat},
{"Single page in \"posts\" section with layout set", LayoutDescriptor{Kind: "page", Type: "posts", Layout: demoLayout}, false, HTMLFormat},
{"Single page in \"posts\" section with theme", LayoutDescriptor{Kind: "page", Type: "posts"}, true, HTMLFormat},
{"AMP single page", LayoutDescriptor{Kind: "page", Type: "posts"}, false, AMPFormat},
{"AMP single page, French language", LayoutDescriptor{Kind: "page", Type: "posts", Lang: "fr"}, false, AMPFormat},
// All section or typeless pages gets "page" as type
{"Home page", LayoutDescriptor{Kind: "home", Type: "page"}, false, HTMLFormat},
{"Home page with type set", LayoutDescriptor{Kind: "home", Type: demoType}, false, HTMLFormat},
{"Home page with layout set", LayoutDescriptor{Kind: "home", Type: "page", Layout: demoLayout}, false, HTMLFormat},
{`Home page with theme`, LayoutDescriptor{Kind: "home", Type: "page"}, true, HTMLFormat},
{`AMP home, French language"`, LayoutDescriptor{Kind: "home", Type: "page", Lang: "fr"}, false, AMPFormat},
{"JSON home", LayoutDescriptor{Kind: "home", Type: "page"}, false, JSONFormat},
{"RSS home with theme", LayoutDescriptor{Kind: "home", Type: "page"}, true, RSSFormat},
{"RSS section posts", LayoutDescriptor{Kind: "section", Type: "posts"}, false, RSSFormat},
{"Taxonomy list in categories", LayoutDescriptor{Kind: "taxonomy", Type: "categories", Section: "category"}, false, RSSFormat},
{"Taxonomy terms in categories", LayoutDescriptor{Kind: "taxonomyTerm", Type: "categories", Section: "category"}, false, RSSFormat},
{"Section list for \"posts\" section", LayoutDescriptor{Kind: "section", Type: "posts", Section: "posts"}, false, HTMLFormat},
{"Section list for \"posts\" section with type set to \"blog\"", LayoutDescriptor{Kind: "section", Type: "blog", Section: "posts"}, false, HTMLFormat},
{"Section list for \"posts\" section with layout set to \"demoLayout\"", LayoutDescriptor{Kind: "section", Layout: demoLayout, Section: "posts"}, false, HTMLFormat},
{"Taxonomy list in categories", LayoutDescriptor{Kind: "taxonomy", Type: "categories", Section: "category"}, false, HTMLFormat},
{"Taxonomy term in categories", LayoutDescriptor{Kind: "taxonomyTerm", Type: "categories", Section: "category"}, false, HTMLFormat},
} {
l := NewLayoutHandler()
layouts, _ := l.For(example.d, example.f)
basicExamples = append(basicExamples, Example{
Example: example.name,
Kind: example.d.Kind,
OutputFormat: example.f.Name,
Suffix: example.f.MediaType.Suffix,
Layouts: makeLayoutsPresentable(layouts)})
}
return basicExamples
}
func makeLayoutsPresentable(l []string) []string {
var filtered []string
for _, ll := range l {
if strings.Contains(ll, "page/") {
// This is a valid lookup, but it's more confusing than useful.
continue
}
ll = strings.TrimPrefix(ll, "_text/")
if strings.Contains(ll, "theme/") {
ll = strings.Replace(ll, "theme/", "demoTheme/layouts/", -1)
} else {
ll = "layouts/" + ll
}
if !strings.Contains(ll, "indexes") {
filtered = append(filtered, ll)
}
}
return filtered
}