jekyll/docs/_docs/datafiles.md

152 lines
3.3 KiB
Markdown

---
layout: docs
title: Data Files
permalink: /docs/datafiles/
---
In addition to the [built-in variables](../variables/) available from Jekyll,
you can specify your own custom data that can be accessed via the [Liquid
templating system](https://wiki.github.com/shopify/liquid/liquid-for-designers).
Jekyll supports loading data from [YAML](http://yaml.org/), [JSON](http://www.json.org/),
and [CSV](https://en.wikipedia.org/wiki/Comma-separated_values) files located in the `_data` directory.
Note that CSV files *must* contain a header row.
This powerful feature allows you to avoid repetition in your templates and to
set site specific options without changing `_config.yml`.
Plugins/themes can also leverage Data Files to set configuration variables.
## The Data Folder
As explained on the [directory structure](../structure/) page, the `_data`
folder is where you can store additional data for Jekyll to use when generating
your site. These files must be YAML, JSON, or CSV files (using either
the `.yml`, `.yaml`, `.json` or `.csv` extension), and they will be
accessible via `site.data`.
## Example: List of members
Here is a basic example of using Data Files to avoid copy-pasting large chunks
of code in your Jekyll templates:
In `_data/members.yml`:
```yaml
- name: Eric Mill
github: konklone
- name: Parker Moore
github: parkr
- name: Liu Fengyun
github: liufengyun
```
Or `_data/members.csv`:
```text
name,github
Eric Mill,konklone
Parker Moore,parkr
Liu Fengyun,liufengyun
```
This data can be accessed via `site.data.members` (notice that the filename
determines the variable name).
You can now render the list of members in a template:
```html
{% raw %}
<ul>
{% for member in site.data.members %}
<li>
<a href="https://github.com/{{ member.github }}">
{{ member.name }}
</a>
</li>
{% endfor %}
</ul>
{% endraw %}
```
## Example: Organizations
Data files can also be placed in sub-folders of the `_data` folder. Each folder
level will be added to a variable's namespace. The example below shows how
GitHub organizations could be defined separately in a file under the `orgs`
folder:
In `_data/orgs/jekyll.yml`:
```yaml
username: jekyll
name: Jekyll
members:
- name: Tom Preston-Werner
github: mojombo
- name: Parker Moore
github: parkr
```
In `_data/orgs/doeorg.yml`:
```yaml
username: doeorg
name: Doe Org
members:
- name: John Doe
github: jdoe
```
The organizations can then be accessed via `site.data.orgs`, followed by the
file name:
```html
{% raw %}
<ul>
{% for org_hash in site.data.orgs %}
{% assign org = org_hash[1] %}
<li>
<a href="https://github.com/{{ org.username }}">
{{ org.name }}
</a>
({{ org.members | size }} members)
</li>
{% endfor %}
</ul>
{% endraw %}
```
## Example: Accessing a specific author
Pages and posts can also access a specific data item. The example below shows how to access a specific item:
`_data/people.yml`:
```yaml
dave:
name: David Smith
twitter: DavidSilvaSmith
```
The author can then be specified as a page variable in a post's frontmatter:
```html
{% raw %}
---
title: sample post
author: dave
---
{% assign author = site.data.people[page.author] %}
<a rel="author"
href="{{ author.twitter }}"
title="{{ author.name }}">
{{ author.name }}
</a>
{% endraw %}
```