mirror of
https://github.com/gohugoio/hugo.git
synced 2024-11-14 20:37:55 -05:00
255 lines
10 KiB
Markdown
255 lines
10 KiB
Markdown
---
|
||
title: Data Templates
|
||
linktitle:
|
||
description: In addition to Hugo's built-in variables, you can specify your own custom data in templates or shortcodes that pull from both local and dynamic sources.
|
||
date: 2017-02-01
|
||
publishdate: 2017-02-01
|
||
lastmod: 2017-03-12
|
||
categories: [templates]
|
||
keywords: [data,dynamic,csv,json,toml,yaml]
|
||
menu:
|
||
docs:
|
||
parent: "templates"
|
||
weight: 80
|
||
weight: 80
|
||
sections_weight: 80
|
||
draft: false
|
||
aliases: [/extras/datafiles/,/extras/datadrivencontent/,/doc/datafiles/]
|
||
toc: true
|
||
---
|
||
|
||
<!-- begin data files -->
|
||
|
||
Hugo supports loading data from YAML, JSON, and TOML files located in the `data` directory in the root of your Hugo project.
|
||
|
||
{{< youtube FyPgSuwIMWQ >}}
|
||
|
||
## The Data Folder
|
||
|
||
The `data` folder is where you can store additional data for Hugo to use when generating your site. Data files aren't used to generate standalone pages; rather, they're meant to be supplemental to content files. This feature can extend the content in case your front matter fields grow out of control. Or perhaps you want to show a larger dataset in a template (see example below). In both cases, it's a good idea to outsource the data in their own files.
|
||
|
||
These files must be YAML, JSON, or TOML files (using the `.yml`, `.yaml`, `.json`, or `.toml` extension). The data will be accessible as a `map` in the `.Site.Data` variable.
|
||
|
||
## Data Files in Themes
|
||
|
||
Data Files can also be used in [Hugo themes][themes] but note that theme data files follow the same logic as other template files in the [Hugo lookup order][lookup] (i.e., given two files with the same name and relative path, the file in the root project `data` directory will override the file in the `themes/<THEME>/data` directory).
|
||
|
||
Therefore, theme authors should take care to not include data files that could be easily overwritten by a user who decides to [customize a theme][customize]. For theme-specific data items that shouldn't be overridden, it can be wise to prefix the folder structure with a namespace; e.g. `mytheme/data/<THEME>/somekey/...`. To check if any such duplicate exists, run hugo with the `-v` flag.
|
||
|
||
The keys in the map created with data templates from data files will be a dot-chained set of `path`, `filename`, and `key` in file (if applicable).
|
||
|
||
This is best explained with an example:
|
||
|
||
## Example: Jaco Pastorius' Solo Discography
|
||
|
||
[Jaco Pastorius](http://en.wikipedia.org/wiki/Jaco_Pastorius_discography) was a great bass player, but his solo discography is short enough to use as an example. [John Patitucci](http://en.wikipedia.org/wiki/John_Patitucci) is another bass giant.
|
||
|
||
The example below is a bit contrived, but it illustrates the flexibility of data Files. This example uses TOML as its file format with the two following data files:
|
||
|
||
* `data/jazz/bass/jacopastorius.toml`
|
||
* `data/jazz/bass/johnpatitucci.toml`
|
||
|
||
`jacopastorius.toml` contains the content below. `johnpatitucci.toml` contains a similar list:
|
||
|
||
```
|
||
discography = [
|
||
"1974 – Modern American Music … Period! The Criteria Sessions",
|
||
"1974 – Jaco",
|
||
"1976 - Jaco Pastorius",
|
||
"1981 - Word of Mouth",
|
||
"1981 - The Birthday Concert (released in 1995)",
|
||
"1982 - Twins I & II (released in 1999)",
|
||
"1983 - Invitation",
|
||
"1986 - Broadway Blues (released in 1998)",
|
||
"1986 - Honestly Solo Live (released in 1990)",
|
||
"1986 - Live In Italy (released in 1991)",
|
||
"1986 - Heavy'n Jazz (released in 1992)",
|
||
"1991 - Live In New York City, Volumes 1-7.",
|
||
"1999 - Rare Collection (compilation)",
|
||
"2003 - Punk Jazz: The Jaco Pastorius Anthology (compilation)",
|
||
"2007 - The Essential Jaco Pastorius (compilation)"
|
||
]
|
||
```
|
||
|
||
The list of bass players can be accessed via `.Site.Data.jazz.bass`, a single bass player by adding the filename without the suffix, e.g. `.Site.Data.jazz.bass.jacopastorius`.
|
||
|
||
You can now render the list of recordings for all the bass players in a template:
|
||
|
||
```
|
||
{{ range $.Site.Data.jazz.bass }}
|
||
{{ partial "artist.html" . }}
|
||
{{ end }}
|
||
```
|
||
|
||
And then in the `partials/artist.html`:
|
||
|
||
```
|
||
<ul>
|
||
{{ range .discography }}
|
||
<li>{{ . }}</li>
|
||
{{ end }}
|
||
</ul>
|
||
```
|
||
|
||
Discover a new favorite bass player? Just add another `.toml` file in the same directory.
|
||
|
||
## Example: Accessing Named Values in a Data File
|
||
|
||
Assume you have the following YAML structure in your `User0123.yml` data file located directly in `data/`:
|
||
|
||
```
|
||
Name: User0123
|
||
"Short Description": "He is a **jolly good** fellow."
|
||
Achievements:
|
||
- "Can create a Key, Value list from Data File"
|
||
- "Learns Hugo"
|
||
- "Reads documentation"
|
||
```
|
||
|
||
You can use the following code to render the `Short Description` in your layout::
|
||
|
||
```
|
||
<div>Short Description of {{.Site.Data.User0123.Name}}: <p>{{ index .Site.Data.User0123 "Short Description" | markdownify }}</p></div>
|
||
```
|
||
|
||
Note the use of the [`markdownify` template function][markdownify]. This will send the description through the Blackfriday Markdown rendering engine.
|
||
|
||
<!-- begin "Data-drive Content" page -->
|
||
|
||
## Data-Driven Content
|
||
|
||
In addition to the [data files](/extras/datafiles/) feature, Hugo also has a "data-driven content" feature, which lets you load any [JSON](http://www.json.org/) or [CSV](http://en.wikipedia.org/wiki/Comma-separated_values) file from nearly any resource.
|
||
|
||
Data-driven content currently consists of two functions, `getJSON` and `getCSV`, which are available in all template files.
|
||
|
||
## Implementation details
|
||
|
||
### Call the Functions with a URL
|
||
|
||
In your template, call the functions like this:
|
||
|
||
```
|
||
{{ $dataJ := getJSON "url" }}
|
||
{{ $dataC := getCSV "separator" "url" }}
|
||
```
|
||
|
||
If you use a prefix or postfix for the URL, the functions accept [variadic arguments][variadic]:
|
||
|
||
```
|
||
{{ $dataJ := getJSON "url prefix" "arg1" "arg2" "arg n" }}
|
||
{{ $dataC := getCSV "separator" "url prefix" "arg1" "arg2" "arg n" }}
|
||
```
|
||
|
||
The separator for `getCSV` must be put in the first position and can only be one character long.
|
||
|
||
All passed arguments will be joined to the final URL:
|
||
|
||
```
|
||
{{ $urlPre := "https://api.github.com" }}
|
||
{{ $gistJ := getJSON $urlPre "/users/GITHUB_USERNAME/gists" }}
|
||
```
|
||
|
||
This will resolve internally to the following:
|
||
|
||
```
|
||
{{ $gistJ := getJSON "https://api.github.com/users/GITHUB_USERNAME/gists" }}
|
||
```
|
||
|
||
Finally, you can range over an array. This example will output the
|
||
first 5 gists for a GitHub user:
|
||
|
||
```
|
||
<ul>
|
||
{{ $urlPre := "https://api.github.com" }}
|
||
{{ $gistJ := getJSON $urlPre "/users/GITHUB_USERNAME/gists" }}
|
||
{{ range first 5 $gistJ }}
|
||
{{ if .public }}
|
||
<li><a href="{{ .html_url }}" target="_blank">{{ .description }}</a></li>
|
||
{{ end }}
|
||
{{ end }}
|
||
</ul>
|
||
```
|
||
|
||
### Example for CSV files
|
||
|
||
For `getCSV`, the one-character-long separator must be placed in the first position followed by the URL. The following is an example of creating an HTML table in a [partial template][partials] from a published CSV:
|
||
|
||
{{< code file="layouts/partials/get-csv.html" >}}
|
||
<table>
|
||
<thead>
|
||
<tr>
|
||
<th>Name</th>
|
||
<th>Position</th>
|
||
<th>Salary</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
{{ $url := "http://a-big-corp.com/finance/employee-salaries.csv" }}
|
||
{{ $sep := "," }}
|
||
{{ range $i, $r := getCSV $sep $url }}
|
||
<tr>
|
||
<td>{{ index $r 0 }}</td>
|
||
<td>{{ index $r 1 }}</td>
|
||
<td>{{ index $r 2 }}</td>
|
||
</tr>
|
||
{{ end }}
|
||
</tbody>
|
||
</table>
|
||
{{< /code >}}
|
||
|
||
The expression `{{index $r number}}` must be used to output the nth-column from the current row.
|
||
|
||
### Cache URLs
|
||
|
||
Each downloaded URL will be cached in the default folder `$TMPDIR/hugo_cache/`. The variable `$TMPDIR` will be resolved to your system-dependent temporary directory.
|
||
|
||
With the command-line flag `--cacheDir`, you can specify any folder on your system as a caching directory.
|
||
|
||
You can also set `cacheDir` in the [main configuration file][config].
|
||
|
||
If you don't like caching at all, you can fully disable caching with the command line flag `--ignoreCache`.
|
||
|
||
### Authentication When Using REST URLs
|
||
|
||
Currently, you can only use those authentication methods that can be put into an URL. [OAuth][] and other authentication methods are not implemented.
|
||
|
||
### Load Local files
|
||
|
||
To load local files with `getJSON` and `getCSV`, the source files must reside within Hugo's working directory. The file extension does not matter, but the content does.
|
||
|
||
It applies the same output logic as above in [Calling the Functions with a URL](#calling-the-functions-with-a-url).
|
||
|
||
## LiveReload with Data Files
|
||
|
||
There is no chance to trigger a [LiveReload][] when the content of a URL changes. However, when a *local* file changes (i.e., `data/*` and `themes/<THEME>/data/*`), a LiveReload will be triggered. Symlinks are not supported. Note too that because downloading of data takes a while, Hugo stops processing your Markdown files until the data download has completed.
|
||
|
||
{{% warning "URL Data and LiveReload" %}}
|
||
If you change any local file and the LiveReload is triggered, Hugo will read the data-driven (URL) content from the cache. If you have disabled the cache (i.e., by running the server with `hugo server --ignoreCache`), Hugo will re-download the content every time LiveReload triggers. This can create *huge* traffic. You may reach API limits quickly.
|
||
{{% /warning %}}
|
||
|
||
## Examples of Data-driven Content
|
||
|
||
- Photo gallery JSON powered: [https://github.com/pcdummy/hugo-lightslider-example](https://github.com/pcdummy/hugo-lightslider-example)
|
||
- GitHub Starred Repositories [in a post](https://github.com/SchumacherFM/blog-cs/blob/master/content%2Fposts%2Fgithub-starred.md) using data-driven content in a [custom short code](https://github.com/SchumacherFM/blog-cs/blob/master/layouts%2Fshortcodes%2FghStarred.html).
|
||
|
||
## Specs for Data Formats
|
||
|
||
* [TOML Spec][toml]
|
||
* [YAML Spec][yaml]
|
||
* [JSON Spec][json]
|
||
* [CSV Spec][csv]
|
||
|
||
[config]: /getting-started/configuration/
|
||
[csv]: https://tools.ietf.org/html/rfc4180
|
||
[customize]: /themes/customizing/
|
||
[json]: https://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf "Specification for JSON, JavaScript Object Notation"
|
||
[LiveReload]: /getting-started/usage/#livereload
|
||
[lookup]: /templates/lookup-order/
|
||
[markdownify]: /functions/markdownify/
|
||
[OAuth]: http://en.wikipedia.org/wiki/OAuth
|
||
[partials]: /templates/partials/
|
||
[themes]: /themes/
|
||
[toml]: https://github.com/toml-lang/toml
|
||
[variadic]: http://en.wikipedia.org/wiki/Variadic_function
|
||
[vars]: /variables/
|
||
[yaml]: http://yaml.org/spec/
|