hugo/resource/resource_metadata.go

130 lines
3.5 KiB
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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
2018-02-20 04:02:14 -05:00
// 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 resource
import (
"fmt"
"strconv"
"github.com/spf13/cast"
"strings"
"github.com/gohugoio/hugo/common/maps"
)
var (
_ metaAssigner = (*genericResource)(nil)
)
// metaAssigner allows updating metadata in resources that supports it.
type metaAssigner interface {
setTitle(title string)
setName(name string)
updateParams(params map[string]interface{})
}
const counterPlaceHolder = ":counter"
// AssignMetadata assigns the given metadata to those resources that supports updates
// and matching by wildcard given in `src` using `filepath.Match` with lower cased values.
// This assignment is additive, but the most specific match needs to be first.
// The `name` and `title` metadata field support shell-matched collection it got a match in.
// See https://golang.org/pkg/path/#Match
func AssignMetadata(metadata []map[string]interface{}, resources ...Resource) error {
counters := make(map[string]int)
for _, r := range resources {
if _, ok := r.(metaAssigner); !ok {
continue
}
var (
nameSet, titleSet bool
nameCounter, titleCounter = 0, 0
nameCounterFound, titleCounterFound bool
resourceSrcKey = strings.ToLower(r.Name())
)
ma := r.(metaAssigner)
for _, meta := range metadata {
src, found := meta["src"]
if !found {
return fmt.Errorf("missing 'src' in metadata for resource")
}
srcKey := strings.ToLower(cast.ToString(src))
glob, err := getGlob(srcKey)
if err != nil {
return fmt.Errorf("failed to match resource with metadata: %s", err)
}
match := glob.Match(resourceSrcKey)
if match {
if !nameSet {
name, found := meta["name"]
if found {
name := cast.ToString(name)
if !nameCounterFound {
nameCounterFound = strings.Contains(name, counterPlaceHolder)
}
if nameCounterFound && nameCounter == 0 {
counterKey := "name_" + srcKey
nameCounter = counters[counterKey] + 1
counters[counterKey] = nameCounter
}
ma.setName(replaceResourcePlaceholders(name, nameCounter))
nameSet = true
}
}
if !titleSet {
title, found := meta["title"]
if found {
title := cast.ToString(title)
if !titleCounterFound {
titleCounterFound = strings.Contains(title, counterPlaceHolder)
}
if titleCounterFound && titleCounter == 0 {
counterKey := "title_" + srcKey
titleCounter = counters[counterKey] + 1
counters[counterKey] = titleCounter
}
ma.setTitle((replaceResourcePlaceholders(title, titleCounter)))
titleSet = true
}
}
params, found := meta["params"]
if found {
m := cast.ToStringMap(params)
// Needed for case insensitive fetching of params values
maps.ToLower(m)
ma.updateParams(m)
}
}
}
}
return nil
}
func replaceResourcePlaceholders(in string, counter int) string {
return strings.Replace(in, counterPlaceHolder, strconv.Itoa(counter), -1)
}