diff options
author | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2018-02-20 10:02:14 +0100 |
---|---|---|
committer | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2018-07-06 11:46:12 +0200 |
commit | dea71670c059ab4d5a42bd22503f18c087dd22d4 (patch) | |
tree | 52889fd27a2d316fad5a04c0f2fe2198491c6cd1 /resource/postcss | |
parent | a5d0a57e6bdab583134a68c035aac9b3007f006a (diff) |
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
Diffstat (limited to 'resource/postcss')
-rw-r--r-- | resource/postcss/postcss.go | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/resource/postcss/postcss.go b/resource/postcss/postcss.go new file mode 100644 index 000000000..7dd27b2f9 --- /dev/null +++ b/resource/postcss/postcss.go @@ -0,0 +1,175 @@ +// 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 postcss + +import ( + "fmt" + "io" + "path/filepath" + + "github.com/gohugoio/hugo/hugofs" + + "github.com/mitchellh/mapstructure" + // "io/ioutil" + "os" + "os/exec" + + "github.com/gohugoio/hugo/common/errors" + + "github.com/gohugoio/hugo/resource" +) + +// Some of the options from https://github.com/postcss/postcss-cli +type Options struct { + + // Set a custom path to look for a config file. + Config string + + NoMap bool `mapstructure:"no-map"` // Disable the default inline sourcemaps + + // Options for when not using a config file + Use string // List of postcss plugins to use + Parser string // Custom postcss parser + Stringifier string // Custom postcss stringifier + Syntax string // Custom postcss syntax +} + +func DecodeOptions(m map[string]interface{}) (opts Options, err error) { + if m == nil { + return + } + err = mapstructure.WeakDecode(m, &opts) + return +} + +func (opts Options) toArgs() []string { + var args []string + if opts.NoMap { + args = append(args, "--no-map") + } + if opts.Use != "" { + args = append(args, "--use", opts.Use) + } + if opts.Parser != "" { + args = append(args, "--parser", opts.Parser) + } + if opts.Stringifier != "" { + args = append(args, "--stringifier", opts.Stringifier) + } + if opts.Syntax != "" { + args = append(args, "--syntax", opts.Syntax) + } + return args +} + +// Client is the client used to do PostCSS transformations. +type Client struct { + rs *resource.Spec +} + +// New creates a new Client with the given specification. +func New(rs *resource.Spec) *Client { + return &Client{rs: rs} +} + +type postcssTransformation struct { + options Options + rs *resource.Spec +} + +func (t *postcssTransformation) Key() resource.ResourceTransformationKey { + return resource.NewResourceTransformationKey("postcss", t.options) +} + +// Transform shells out to postcss-cli to do the heavy lifting. +// For this to work, you need some additional tools. To install them globally: +// npm install -g postcss-cli +// npm install -g autoprefixer +func (t *postcssTransformation) Transform(ctx *resource.ResourceTransformationCtx) error { + + const binary = "postcss" + + if _, err := exec.LookPath(binary); err != nil { + // This may be on a CI server etc. Will fall back to pre-built assets. + return errors.FeatureNotAvailableErr + } + + var configFile string + logger := t.rs.Logger + + if t.options.Config != "" { + configFile = t.options.Config + } else { + configFile = "postcss.config.js" + } + + configFile = filepath.Clean(configFile) + + // We need an abolute filename to the config file. + if !filepath.IsAbs(configFile) { + // We resolve this against the virtual Work filesystem, to allow + // this config file to live in one of the themes if needed. + fi, err := t.rs.BaseFs.Work.Fs.Stat(configFile) + if err != nil { + if t.options.Config != "" { + // Only fail if the user specificed config file is not found. + return fmt.Errorf("postcss config %q not found: %s", configFile, err) + } + configFile = "" + } else { + configFile = fi.(hugofs.RealFilenameInfo).RealFilename() + } + } + + var cmdArgs []string + + if configFile != "" { + logger.INFO.Println("postcss: use config file", configFile) + cmdArgs = []string{"--config", configFile} + } + + if optArgs := t.options.toArgs(); len(optArgs) > 0 { + cmdArgs = append(cmdArgs, optArgs...) + } + + cmd := exec.Command(binary, cmdArgs...) + + cmd.Stdout = ctx.To + cmd.Stderr = os.Stderr + + stdin, err := cmd.StdinPipe() + if err != nil { + return err + } + + go func() { + defer stdin.Close() + io.Copy(stdin, ctx.From) + }() + + err = cmd.Run() + if err != nil { + return err + } + + return nil +} + +// Process transforms the given Resource with the PostCSS processor. +func (c *Client) Process(res resource.Resource, options Options) (resource.Resource, error) { + return c.rs.Transform( + res, + &postcssTransformation{rs: c.rs, options: options}, + ) +} |