hugo/docs/content/en/content-management/page-resources.md
2024-09-01 14:51:15 +02:00

310 lines
9.7 KiB
Markdown

---
title: Page resources
description: Use page resources to logically associate assets with a page.
categories: [content management]
keywords: [bundle,content,resources]
menu:
docs:
parent: content-management
weight: 80
weight: 80
toc: true
---
Page resources are only accessible from [page bundles](/content-management/page-bundles), those directories with `index.md` or
`_index.md` files at their root. Page resources are only available to the
page with which they are bundled.
In this example, `first-post` is a page bundle with access to 10 page resources including audio, data, documents, images, and video. Although `second-post` is also a page bundle, it has no page resources and is unable to directly access the page resources associated with `first-post`.
```text
content
└── post
├── first-post
│ ├── images
│ │ ├── a.jpg
│ │ ├── b.jpg
│ │ └── c.jpg
│ ├── index.md (root of page bundle)
│ ├── latest.html
│ ├── manual.json
│ ├── notice.md
│ ├── office.mp3
│ ├── pocket.mp4
│ ├── rating.pdf
│ └── safety.txt
└── second-post
└── index.md (root of page bundle)
```
## Examples
Use any of these methods on a `Page` object to capture page resources:
- [`Resources.ByType`]
- [`Resources.Get`]
- [`Resources.GetMatch`]
- [`Resources.Match`]
Once you have captured a resource, use any of the applicable [`Resource`] methods to return a value or perform an action.
[`Resource`]: /methods/resource
[`Resources.ByType`]: /methods/page/resources#bytype
[`Resources.GetMatch`]: /methods/page/resources#getmatch
[`Resources.Get`]: /methods/page/resources#get
[`Resources.Match`]: /methods/page/resources#match
The following examples assume this content structure:
```text
content/
└── example/
├── data/
│ └── books.json <-- page resource
├── images/
│ ├── a.jpg <-- page resource
│ └── b.jpg <-- page resource
├── snippets/
│ └── text.md <-- page resource
└── index.md
```
Render a single image, and throw an error if the file does not exist:
```go-html-template
{{ $path := "images/a.jpg" }}
{{ with .Resources.Get $path }}
<img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
{{ else }}
{{ errorf "Unable to get page resource %q" $path }}
{{ end }}
```
Render all images, resized to 300 px wide:
```go-html-template
{{ range .Resources.ByType "image" }}
{{ with .Resize "300x" }}
<img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
{{ end }}
{{ end }}
```
Render the markdown snippet:
```go-html-template
{{ with .Resources.Get "snippets/text.md" }}
{{ .Content }}
{{ end }}
```
List the titles in the data file, and throw an error if the file does not exist.
```go-html-template
{{ $path := "data/books.json" }}
{{ with .Resources.Get $path }}
{{ with . | transform.Unmarshal }}
<p>Books:</p>
<ul>
{{ range . }}
<li>{{ .title }}</li>
{{ end }}
</ul>
{{ end }}
{{ else }}
{{ errorf "Unable to get page resource %q" $path }}
{{ end }}
```
## Metadata
The page resources' metadata is managed from the corresponding page's front matter with an array/table parameter named `resources`. You can batch assign values using [wildcards](https://tldp.org/LDP/GNU-Linux-Tools-Summary/html/x11655.htm).
{{% note %}}
Resources of type `page` get `Title` etc. from their own front matter.
{{% /note %}}
name
: (`string`) Sets the value returned in `Name`.
{{% note %}}
The methods `Match`, `Get` and `GetMatch` use `Name` to match the resources.
{{% /note %}}
title
: (`string`) Sets the value returned in `Title`
params
: (`map`) A map of custom key-value pairs.
### Resources metadata example
{{< code-toggle file=content/example.md fm=true >}}
title: Application
date : 2018-01-25
resources :
- src : "images/sunset.jpg"
name : "header"
- src : "documents/photo_specs.pdf"
title : "Photo Specifications"
params:
icon : "photo"
- src : "documents/guide.pdf"
title : "Instruction Guide"
- src : "documents/checklist.pdf"
title : "Document Checklist"
- src : "documents/payment.docx"
title : "Proof of Payment"
- src : "**.pdf"
name : "pdf-file-:counter"
params :
icon : "pdf"
- src : "**.docx"
params :
icon : "word"
{{</ code-toggle >}}
From the example above:
- `sunset.jpg` will receive a new `Name` and can now be found with `.GetMatch "header"`.
- `documents/photo_specs.pdf` will get the `photo` icon.
- `documents/checklist.pdf`, `documents/guide.pdf` and `documents/payment.docx` will get `Title` as set by `title`.
- Every `PDF` in the bundle except `documents/photo_specs.pdf` will get the `pdf` icon.
- All `PDF` files will get a new `Name`. The `name` parameter contains a special placeholder [`:counter`](#the-counter-placeholder-in-name-and-title), so the `Name` will be `pdf-file-1`, `pdf-file-2`, `pdf-file-3`.
- Every docx in the bundle will receive the `word` icon.
{{% note %}}
The order matters; only the first set values of the `title`, `name` and `params` keys will be used. Consecutive parameters will be set only for the ones not already set. In the above example, `.Params.icon` is first set to `"photo"` in `src = "documents/photo_specs.pdf"`. So that would not get overridden to `"pdf"` by the later set `src = "**.pdf"` rule.
{{% /note %}}
### The `:counter` placeholder in `name` and `title`
The `:counter` is a special placeholder recognized in `name` and `title` parameters `resources`.
The counter starts at 1 the first time they are used in either `name` or `title`.
For example, if a bundle has the resources `photo_specs.pdf`, `other_specs.pdf`, `guide.pdf` and `checklist.pdf`, and the front matter has specified the `resources` as:
{{< code-toggle file=content/inspections/engine/index.md fm=true >}}
title = 'Engine inspections'
[[resources]]
src = "*specs.pdf"
title = "Specification #:counter"
[[resources]]
src = "**.pdf"
name = "pdf-file-:counter"
{{</ code-toggle >}}
the `Name` and `Title` will be assigned to the resource files as follows:
| Resource file | `Name` | `Title` |
|-------------------|-------------------|-----------------------|
| checklist.pdf | `"pdf-file-1.pdf` | `"checklist.pdf"` |
| guide.pdf | `"pdf-file-2.pdf` | `"guide.pdf"` |
| other\_specs.pdf | `"pdf-file-3.pdf` | `"Specification #1"` |
| photo\_specs.pdf | `"pdf-file-4.pdf` | `"Specification #2"` |
## Multilingual
{{< new-in 0.123.0 >}}
By default, with a multilingual single-host site, Hugo does not duplicate shared page resources when building the site.
{{% note %}}
This behavior is limited to Markdown content. Shared page resources for other [content formats] are copied into each language bundle.
[content formats]: /content-management/formats/
{{% /note %}}
Consider this site configuration:
{{< code-toggle file=hugo >}}
defaultContentLanguage = 'de'
defaultContentLanguageInSubdir = true
[languages.de]
languageCode = 'de-DE'
languageName = 'Deutsch'
weight = 1
[languages.en]
languageCode = 'en-US'
languageName = 'English'
weight = 2
{{< /code-toggle >}}
And this content:
```text
content/
└── my-bundle/
├── a.jpg <-- shared page resource
├── b.jpg <-- shared page resource
├── c.de.jpg
├── c.en.jpg
├── index.de.md
└── index.en.md
```
With v0.122.0 and earlier, Hugo duplicated the shared page resources, creating copies for each language:
```text
public/
├── de/
│ ├── my-bundle/
│ │ ├── a.jpg <-- shared page resource
│ │ ├── b.jpg <-- shared page resource
│ │ ├── c.de.jpg
│ │ └── index.html
│ └── index.html
├── en/
│ ├── my-bundle/
│ │ ├── a.jpg <-- shared page resource (duplicate)
│ │ ├── b.jpg <-- shared page resource (duplicate)
│ │ ├── c.en.jpg
│ │ └── index.html
│ └── index.html
└── index.html
```
With v0.123.0 and later, Hugo places the shared resources in the page bundle for the default content language:
```text
public/
├── de/
│ ├── my-bundle/
│ │ ├── a.jpg <-- shared page resource
│ │ ├── b.jpg <-- shared page resource
│ │ ├── c.de.jpg
│ │ └── index.html
│ └── index.html
├── en/
│ ├── my-bundle/
│ │ ├── c.en.jpg
│ │ └── index.html
│ └── index.html
└── index.html
```
This approach reduces build times, storage requirements, bandwidth consumption, and deployment times, ultimately reducing cost.
{{% note %}}
To resolve Markdown link and image destinations to the correct location, you must use link and image render hooks that capture the page resource with the [`Resources.Get`] method, and then invoke its [`RelPermalink`] method.
By default, with multilingual single-host sites, Hugo enables its [embedded link render hook] and [embedded image render hook] to resolve Markdown link and image destinations.
You may override the embedded render hooks as needed, provided they capture the resource as described above.
[embedded link render hook]: /render-hooks/links/#default
[embedded image render hook]: /render-hooks/images/#default
[`Resources.Get`]: /methods/page/resources/#get
[`RelPermalink`]: /methods/resource/relpermalink/
{{% /note %}}
Although duplicating shared page resources is inefficient, you can enable this feature in your site configuration if desired:
{{< code-toggle file=hugo >}}
[markup.goldmark]
duplicateResourceFiles = true
{{< /code-toggle >}}