hugo/hugolib/page_bundler_handlers.go
Bjørn Erik Pedersen dea71670c0
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
2018-07-06 11:46:12 +02:00

359 lines
7.8 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 hugolib
import (
"errors"
"fmt"
"path/filepath"
"sort"
"strings"
"github.com/gohugoio/hugo/helpers"
"github.com/gohugoio/hugo/resource"
)
var (
// This should be the only list of valid extensions for content files.
contentFileExtensions = []string{
"html", "htm",
"mdown", "markdown", "md",
"asciidoc", "adoc", "ad",
"rest", "rst",
"mmark",
"org",
"pandoc", "pdc"}
contentFileExtensionsSet map[string]bool
)
func init() {
contentFileExtensionsSet = make(map[string]bool)
for _, ext := range contentFileExtensions {
contentFileExtensionsSet[ext] = true
}
}
func newHandlerChain(s *Site) contentHandler {
c := &contentHandlers{s: s}
contentFlow := c.parsePage(c.processFirstMatch(
// Handles all files with a content file extension. See above.
c.handlePageContent(),
// Every HTML file without front matter will be passed on to this handler.
c.handleHTMLContent(),
))
c.rootHandler = c.processFirstMatch(
contentFlow,
// Creates a file resource (image, CSS etc.) if there is a parent
// page set on the current context.
c.createResource(),
// Everything that isn't handled above, will just be copied
// to destination.
c.copyFile(),
)
return c.rootHandler
}
type contentHandlers struct {
s *Site
rootHandler contentHandler
}
func (c *contentHandlers) processFirstMatch(handlers ...contentHandler) func(ctx *handlerContext) handlerResult {
return func(ctx *handlerContext) handlerResult {
for _, h := range handlers {
res := h(ctx)
if res.handled || res.err != nil {
return res
}
}
return handlerResult{err: errors.New("no matching handler found")}
}
}
type handlerContext struct {
// These are the pages stored in Site.
pages chan<- *Page
doNotAddToSiteCollections bool
currentPage *Page
parentPage *Page
bundle *bundleDir
source *fileInfo
// Relative path to the target.
target string
}
func (c *handlerContext) ext() string {
if c.currentPage != nil {
if c.currentPage.Markup != "" {
return c.currentPage.Markup
}
return c.currentPage.Ext()
}
if c.bundle != nil {
return c.bundle.fi.Ext()
} else {
return c.source.Ext()
}
}
func (c *handlerContext) targetPath() string {
if c.target != "" {
return c.target
}
return c.source.Filename()
}
func (c *handlerContext) file() *fileInfo {
if c.bundle != nil {
return c.bundle.fi
}
return c.source
}
// Create a copy with the current context as its parent.
func (c handlerContext) childCtx(fi *fileInfo) *handlerContext {
if c.currentPage == nil {
panic("Need a Page to create a child context")
}
c.target = strings.TrimPrefix(fi.Path(), c.bundle.fi.Dir())
c.source = fi
c.doNotAddToSiteCollections = c.bundle != nil && c.bundle.tp != bundleBranch
c.bundle = nil
c.parentPage = c.currentPage
c.currentPage = nil
return &c
}
func (c *handlerContext) supports(exts ...string) bool {
ext := c.ext()
for _, s := range exts {
if s == ext {
return true
}
}
return false
}
func (c *handlerContext) isContentFile() bool {
return contentFileExtensionsSet[c.ext()]
}
type (
handlerResult struct {
err error
handled bool
resource resource.Resource
}
contentHandler func(ctx *handlerContext) handlerResult
)
var (
notHandled handlerResult
)
func (c *contentHandlers) parsePage(h contentHandler) contentHandler {
return func(ctx *handlerContext) handlerResult {
if !ctx.isContentFile() {
return notHandled
}
result := handlerResult{handled: true}
fi := ctx.file()
f, err := fi.Open()
if err != nil {
return handlerResult{err: fmt.Errorf("(%s) failed to open content file: %s", fi.Filename(), err)}
}
defer f.Close()
p := c.s.newPageFromFile(fi)
_, err = p.ReadFrom(f)
if err != nil {
return handlerResult{err: err}
}
if !p.shouldBuild() {
if !ctx.doNotAddToSiteCollections {
ctx.pages <- p
}
return result
}
ctx.currentPage = p
if ctx.bundle != nil {
// Add the bundled files
for _, fi := range ctx.bundle.resources {
childCtx := ctx.childCtx(fi)
res := c.rootHandler(childCtx)
if res.err != nil {
return res
}
if res.resource != nil {
if pageResource, ok := res.resource.(*Page); ok {
pageResource.resourcePath = filepath.ToSlash(childCtx.target)
pageResource.parent = p
}
p.Resources = append(p.Resources, res.resource)
}
}
sort.SliceStable(p.Resources, func(i, j int) bool {
if p.Resources[i].ResourceType() < p.Resources[j].ResourceType() {
return true
}
p1, ok1 := p.Resources[i].(*Page)
p2, ok2 := p.Resources[j].(*Page)
if ok1 != ok2 {
return ok2
}
if ok1 {
return defaultPageSort(p1, p2)
}
return p.Resources[i].RelPermalink() < p.Resources[j].RelPermalink()
})
// Assign metadata from front matter if set
if len(p.resourcesMetadata) > 0 {
resource.AssignMetadata(p.resourcesMetadata, p.Resources...)
}
}
return h(ctx)
}
}
func (c *contentHandlers) handlePageContent() contentHandler {
return func(ctx *handlerContext) handlerResult {
if ctx.supports("html", "htm") {
return notHandled
}
p := ctx.currentPage
// Work on a copy of the raw content from now on.
p.createWorkContentCopy()
if err := p.processShortcodes(); err != nil {
p.s.Log.ERROR.Println(err)
}
if c.s.Cfg.GetBool("enableEmoji") {
p.workContent = helpers.Emojify(p.workContent)
}
p.workContent = p.replaceDivider(p.workContent)
p.workContent = p.renderContent(p.workContent)
tmpContent, tmpTableOfContents := helpers.ExtractTOC(p.workContent)
p.TableOfContents = helpers.BytesToHTML(tmpTableOfContents)
p.workContent = tmpContent
if !ctx.doNotAddToSiteCollections {
ctx.pages <- p
}
return handlerResult{handled: true, resource: p}
}
}
func (c *contentHandlers) handleHTMLContent() contentHandler {
return func(ctx *handlerContext) handlerResult {
if !ctx.supports("html", "htm") {
return notHandled
}
p := ctx.currentPage
p.createWorkContentCopy()
if err := p.processShortcodes(); err != nil {
p.s.Log.ERROR.Println(err)
}
if !ctx.doNotAddToSiteCollections {
ctx.pages <- p
}
return handlerResult{handled: true, resource: p}
}
}
func (c *contentHandlers) createResource() contentHandler {
return func(ctx *handlerContext) handlerResult {
if ctx.parentPage == nil {
return notHandled
}
resource, err := c.s.ResourceSpec.New(
resource.ResourceSourceDescriptor{
TargetPathBuilder: ctx.parentPage.subResourceTargetPathFactory,
SourceFile: ctx.source,
RelTargetFilename: ctx.target,
URLBase: c.s.GetURLLanguageBasePath(),
TargetPathBase: c.s.GetTargetLanguageBasePath(),
})
return handlerResult{err: err, handled: true, resource: resource}
}
}
func (c *contentHandlers) copyFile() contentHandler {
return func(ctx *handlerContext) handlerResult {
f, err := c.s.BaseFs.Content.Fs.Open(ctx.source.Filename())
if err != nil {
err := fmt.Errorf("failed to open file in copyFile: %s", err)
return handlerResult{err: err}
}
target := ctx.targetPath()
defer f.Close()
if err := c.s.publish(&c.s.PathSpec.ProcessingStats.Files, target, f); err != nil {
return handlerResult{err: err}
}
return handlerResult{handled: true}
}
}