hugo/tpl/partials/partials.go

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// Copyright 2017 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 partials provides template functions for working with reusable
// templates.
package partials
import (
"context"
"errors"
"fmt"
"html/template"
"io"
"io/ioutil"
"reflect"
"strings"
"sync"
"time"
texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
"github.com/gohugoio/hugo/helpers"
"github.com/gohugoio/hugo/tpl"
bp "github.com/gohugoio/hugo/bufferpool"
"github.com/gohugoio/hugo/deps"
)
// TestTemplateProvider is global deps.ResourceProvider.
// NOTE: It's currently unused.
var TestTemplateProvider deps.ResourceProvider
type partialCacheKey struct {
name string
variant any
}
func (k partialCacheKey) templateName() string {
if !strings.HasPrefix(k.name, "partials/") {
return "partials/" + k.name
}
return k.name
}
// partialCache represents a cache of partials protected by a mutex.
type partialCache struct {
sync.RWMutex
p map[partialCacheKey]any
}
func (p *partialCache) clear() {
p.Lock()
defer p.Unlock()
p.p = make(map[partialCacheKey]any)
}
// New returns a new instance of the templates-namespaced template functions.
func New(deps *deps.Deps) *Namespace {
cache := &partialCache{p: make(map[partialCacheKey]any)}
deps.BuildStartListeners.Add(
func() {
cache.clear()
})
return &Namespace{
deps: deps,
cachedPartials: cache,
}
}
// Namespace provides template functions for the "templates" namespace.
type Namespace struct {
deps *deps.Deps
cachedPartials *partialCache
}
// contextWrapper makes room for a return value in a partial invocation.
type contextWrapper struct {
Arg any
Result any
}
// Set sets the return value and returns an empty string.
func (c *contextWrapper) Set(in any) string {
c.Result = in
return ""
}
// Include executes the named partial.
// If the partial contains a return statement, that value will be returned.
// Else, the rendered output will be returned:
// A string if the partial is a text/template, or template.HTML when html/template.
// Note that ctx is provided by Hugo, not the end user.
func (ns *Namespace) Include(ctx context.Context, name string, contextList ...any) (any, error) {
name, result, err := ns.include(ctx, name, contextList...)
if err != nil {
return result, err
}
if ns.deps.Metrics != nil {
ns.deps.Metrics.TrackValue(name, result, false)
}
return result, nil
}
// include is a helper function that lookups and executes the named partial.
// Returns the final template name and the rendered output.
func (ns *Namespace) include(ctx context.Context, name string, dataList ...any) (string, any, error) {
var data any
if len(dataList) > 0 {
data = dataList[0]
}
var n string
if strings.HasPrefix(name, "partials/") {
n = name
} else {
n = "partials/" + name
}
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 09:02:14 +00:00
templ, found := ns.deps.Tmpl().Lookup(n)
if !found {
// For legacy reasons.
tpl/tplimpl: Rework template management to get rid of concurrency issues This more or less completes the simplification of the template handling code in Hugo started in v0.62. The main motivation was to fix a long lasting issue about a crash in HTML content files without front matter. But this commit also comes with a big functional improvement. As we now have moved the base template evaluation to the build stage we now use the same lookup rules for `baseof` as for `list` etc. type of templates. This means that in this simple example you can have a `baseof` template for the `blog` section without having to duplicate the others: ``` layouts ├── _default │   ├── baseof.html │   ├── list.html │   └── single.html └── blog └── baseof.html ``` Also, when simplifying code, you often get rid of some double work, as shown in the "site building" benchmarks below. These benchmarks looks suspiciously good, but I have repeated the below with ca. the same result. Compared to master: ``` name old time/op new time/op delta SiteNew/Bundle_with_image-16 13.1ms ± 1% 10.5ms ± 1% -19.34% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 13.0ms ± 0% 10.7ms ± 1% -18.05% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 46.4ms ± 2% 43.1ms ± 1% -7.15% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 52.2ms ± 2% 47.8ms ± 1% -8.30% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 77.9ms ± 1% 70.9ms ± 1% -9.01% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 43.0ms ± 0% 37.2ms ± 1% -13.54% (p=0.029 n=4+4) SiteNew/Page_collections-16 58.2ms ± 1% 52.4ms ± 1% -9.95% (p=0.029 n=4+4) name old alloc/op new alloc/op delta SiteNew/Bundle_with_image-16 3.81MB ± 0% 2.22MB ± 0% -41.70% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 3.60MB ± 0% 2.01MB ± 0% -44.20% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 19.3MB ± 1% 14.1MB ± 0% -26.91% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 70.7MB ± 0% 69.0MB ± 0% -2.40% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 37.1MB ± 0% 31.2MB ± 0% -15.94% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 17.6MB ± 0% 10.6MB ± 0% -39.92% (p=0.029 n=4+4) SiteNew/Page_collections-16 25.9MB ± 0% 21.2MB ± 0% -17.99% (p=0.029 n=4+4) name old allocs/op new allocs/op delta SiteNew/Bundle_with_image-16 52.3k ± 0% 26.1k ± 0% -50.18% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 52.3k ± 0% 26.1k ± 0% -50.16% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 336k ± 1% 269k ± 0% -19.90% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 422k ± 0% 395k ± 0% -6.43% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 401k ± 0% 313k ± 0% -21.79% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 247k ± 0% 143k ± 0% -42.17% (p=0.029 n=4+4) SiteNew/Page_collections-16 282k ± 0% 207k ± 0% -26.55% (p=0.029 n=4+4) ``` Fixes #6716 Fixes #6760 Fixes #6768 Fixes #6778
2020-01-15 14:59:56 +00:00
templ, found = ns.deps.Tmpl().Lookup(n + ".html")
}
if !found {
return "", "", fmt.Errorf("partial %q not found", name)
}
var info tpl.ParseInfo
if ip, ok := templ.(tpl.Info); ok {
info = ip.ParseInfo()
}
var w io.Writer
if info.HasReturn {
// Wrap the context sent to the template to capture the return value.
// Note that the template is rewritten to make sure that the dot (".")
// and the $ variable points to Arg.
data = &contextWrapper{
Arg: data,
}
// We don't care about any template output.
w = ioutil.Discard
} else {
b := bp.GetBuffer()
defer bp.PutBuffer(b)
w = b
}
if err := ns.deps.Tmpl().ExecuteWithContext(ctx, templ, w, data); err != nil {
return "", nil, err
}
var result any
if ctx, ok := data.(*contextWrapper); ok {
result = ctx.Result
} else if _, ok := templ.(*texttemplate.Template); ok {
result = w.(fmt.Stringer).String()
} else {
result = template.HTML(w.(fmt.Stringer).String())
}
return templ.Name(), result, nil
}
// IncludeCached executes and caches partial templates. The cache is created with name+variants as the key.
// Note that ctx is provided by Hugo, not the end user.
func (ns *Namespace) IncludeCached(ctx context.Context, name string, context any, variants ...any) (any, error) {
key, err := createKey(name, variants...)
if err != nil {
return nil, err
}
result, err := ns.getOrCreate(ctx, key, context)
if err == errUnHashable {
// Try one more
key.variant = helpers.HashString(key.variant)
result, err = ns.getOrCreate(ctx, key, context)
}
return result, err
}
func createKey(name string, variants ...any) (partialCacheKey, error) {
var variant any
if len(variants) > 1 {
variant = helpers.HashString(variants...)
} else if len(variants) == 1 {
variant = variants[0]
t := reflect.TypeOf(variant)
switch t.Kind() {
// This isn't an exhaustive list of unhashable types.
// There may be structs with slices,
// but that should be very rare. We do recover from that situation
// below.
case reflect.Slice, reflect.Array, reflect.Map:
variant = helpers.HashString(variant)
}
}
return partialCacheKey{name: name, variant: variant}, nil
}
var errUnHashable = errors.New("unhashable")
func (ns *Namespace) getOrCreate(ctx context.Context, key partialCacheKey, context any) (result any, err error) {
start := time.Now()
defer func() {
if r := recover(); r != nil {
err = r.(error)
if strings.Contains(err.Error(), "unhashable type") {
ns.cachedPartials.RUnlock()
err = errUnHashable
}
}
}()
ns.cachedPartials.RLock()
p, ok := ns.cachedPartials.p[key]
ns.cachedPartials.RUnlock()
if ok {
if ns.deps.Metrics != nil {
ns.deps.Metrics.TrackValue(key.templateName(), p, true)
// The templates that gets executed is measured in Execute.
// We need to track the time spent in the cache to
// get the totals correct.
ns.deps.Metrics.MeasureSince(key.templateName(), start)
}
return p, nil
}
// This needs to be done outside the lock.
// See #9588
_, p, err = ns.include(ctx, key.name, context)
if err != nil {
return nil, err
}
ns.cachedPartials.Lock()
defer ns.cachedPartials.Unlock()
// Double-check.
if p2, ok := ns.cachedPartials.p[key]; ok {
if ns.deps.Metrics != nil {
ns.deps.Metrics.TrackValue(key.templateName(), p, true)
ns.deps.Metrics.MeasureSince(key.templateName(), start)
}
return p2, nil
}
if ns.deps.Metrics != nil {
ns.deps.Metrics.TrackValue(key.templateName(), p, false)
}
ns.cachedPartials.p[key] = p
return p, nil
}