hugo/resources/resource_transformers/tocss/scss/client.go
Bjørn Erik Pedersen 41a080b268 tocss: Add vars option
This commit adds a new `vars` option to both the Sass transpilers (Dart Sass and Libsass).

This means that you can pass a map with key/value pairs to the transpiler:

```handlebars
{{ $vars := dict "$color1" "blue" "$color2" "green" "$font_size" "24px" }}
{{ $cssOpts := (dict "transpiler" "dartsass" "outputStyle" "compressed" "vars" $vars ) }}
{{ $r := resources.Get "scss/main.scss" |  toCSS $cssOpts }}
```

And the the variables will be available in the `hugo:vars` namespace. Example usage for Dart Sass:

```scss
@use "hugo:vars" as v;

p {
    color: v.$color1;
    font-size: v.$font_size;
}
```

Note that Libsass does not support the `use` keyword, so you need to `import` them as global variables:

```scss
@import "hugo:vars";

p {
    color: $color1;
    font-size: $font_size;
}
```

Hugo will:

* Add a missing leading `$` for the variable names if needed.
* Wrap the values in `unquote('VALUE')` (Sass built-in) to get proper handling of identifiers vs other strings.

This means that you can pull variables directly from e.g. the site config:

```toml
[params]
[params.sassvars]
color1 = "blue"
color2 = "green"
font_size = "24px"
image = "images/hero.jpg"
```

```handlebars
{{ $vars := site.Params.sassvars}}
{{ $cssOpts := (dict "transpiler" "dartsass" "outputStyle" "compressed" "vars" $vars ) }}
{{ $r := resources.Get "scss/main.scss" |  toCSS $cssOpts }}
```

Fixes #10555
2022-12-20 19:36:30 +01:00

94 lines
2.8 KiB
Go

// Copyright 2018 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 scss
import (
"regexp"
"github.com/gohugoio/hugo/helpers"
"github.com/gohugoio/hugo/hugolib/filesystems"
"github.com/gohugoio/hugo/resources"
"github.com/spf13/afero"
"github.com/mitchellh/mapstructure"
)
const transformationName = "tocss"
type Client struct {
rs *resources.Spec
sfs *filesystems.SourceFilesystem
workFs afero.Fs
}
func New(fs *filesystems.SourceFilesystem, rs *resources.Spec) (*Client, error) {
return &Client{sfs: fs, workFs: rs.BaseFs.Work, rs: rs}, nil
}
type Options struct {
// Hugo, will by default, just replace the extension of the source
// to .css, e.g. "scss/main.scss" becomes "scss/main.css". You can
// control this by setting this, e.g. "styles/main.css" will create
// a Resource with that as a base for RelPermalink etc.
TargetPath string
// Hugo automatically adds the entry directories (where the main.scss lives)
// for project and themes to the list of include paths sent to LibSASS.
// Any paths set in this setting will be appended. Note that these will be
// treated as relative to the working dir, i.e. no include paths outside the
// project/themes.
IncludePaths []string
// Default is nested.
// One of nested, expanded, compact, compressed.
OutputStyle string
// Precision of floating point math.
Precision int
// When enabled, Hugo will generate a source map.
EnableSourceMap bool
// Vars will be available in 'hugo:vars', e.g:
// @import "hugo:vars";
Vars map[string]string
}
func DecodeOptions(m map[string]any) (opts Options, err error) {
if m == nil {
return
}
err = mapstructure.WeakDecode(m, &opts)
if opts.TargetPath != "" {
opts.TargetPath = helpers.ToSlashTrimLeading(opts.TargetPath)
}
return
}
var (
regularCSSImportTo = regexp.MustCompile(`.*(@import "(.*\.css)";).*`)
regularCSSImportFrom = regexp.MustCompile(`.*(\/\* HUGO_IMPORT_START (.*) HUGO_IMPORT_END \*\/).*`)
)
func replaceRegularImportsIn(s string) (string, bool) {
replaced := regularCSSImportTo.ReplaceAllString(s, "/* HUGO_IMPORT_START $2 HUGO_IMPORT_END */")
return replaced, s != replaced
}
func replaceRegularImportsOut(s string) string {
return regularCSSImportFrom.ReplaceAllString(s, "@import \"$2\";")
}