154 lines
5.8 KiB
Markdown
154 lines
5.8 KiB
Markdown
---
|
|
title: Front Matter Defaults
|
|
permalink: "/docs/configuration/front-matter-defaults/"
|
|
---
|
|
|
|
Using [front matter](/docs/front-matter/) is one way that you can specify configuration in the pages and posts for your site. Setting things like a default layout, or customizing the title, or specifying a more precise date/time for the post can all be added to your page or post front matter.
|
|
|
|
Often times, you will find that you are repeating a lot of configuration options. Setting the same layout in each file, adding the same category - or categories - to a post, etc. You can even add custom variables like author names, which might be the same for the majority of posts on your blog.
|
|
|
|
Instead of repeating this configuration each time you create a new post or page, Jekyll provides a way to set these defaults in the site configuration. To do this, you can specify site-wide defaults using the `defaults` key in the `_config.yml` file in your project's root directory.
|
|
|
|
The `defaults` key holds an array of scope/values pairs that define what defaults should be set for a particular file path, and optionally, a file type in that path.
|
|
|
|
Let's say that you want to add a default layout to all pages and posts in your site. You would add this to your `_config.yml` file:
|
|
|
|
```yaml
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: "" # an empty string here means all files in the project
|
|
values:
|
|
layout: "default"
|
|
```
|
|
|
|
<div class="note info">
|
|
<h5>Stop and rerun `jekyll serve` command.</h5>
|
|
<p>
|
|
The <code>_config.yml</code> master configuration file contains global configurations
|
|
and variable definitions that are read once at execution time. Changes made to <code>_config.yml</code>
|
|
during automatic regeneration are not loaded until the next execution.
|
|
</p>
|
|
<p>
|
|
Note <a href="{{ '/docs/datafiles' | relative_url }}">Data Files</a> are included and reloaded during automatic regeneration.
|
|
</p>
|
|
</div>
|
|
|
|
Here, we are scoping the `values` to any file that exists in the path `scope`. Since the path is set as an empty string, it will apply to **all files** in your project. You probably don't want to set a layout on every file in your project - like css files, for example - so you can also specify a `type` value under the `scope` key.
|
|
|
|
```yaml
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: "" # an empty string here means all files in the project
|
|
type: "posts" # previously `post` in Jekyll 2.2.
|
|
values:
|
|
layout: "default"
|
|
```
|
|
|
|
Now, this will only set the layout for files where the type is `posts`.
|
|
The different types that are available to you are `pages`, `posts`, `drafts` or any collection in your site. While `type` is optional, you must specify a value for `path` when creating a `scope/values` pair.
|
|
|
|
As mentioned earlier, you can set multiple scope/values pairs for `defaults`.
|
|
|
|
```yaml
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: ""
|
|
type: "pages"
|
|
values:
|
|
layout: "my-site"
|
|
-
|
|
scope:
|
|
path: "projects"
|
|
type: "pages" # previously `page` in Jekyll 2.2.
|
|
values:
|
|
layout: "project" # overrides previous default layout
|
|
author: "Mr. Hyde"
|
|
```
|
|
|
|
With these defaults, all pages would use the `my-site` layout. Any html files that exist in the `projects/`
|
|
folder will use the `project` layout, if it exists. Those files will also have the `page.author`
|
|
[liquid variable]({{ '/docs/variables/' | relative_url }}) set to `Mr. Hyde`.
|
|
|
|
```yaml
|
|
collections:
|
|
my_collection:
|
|
output: true
|
|
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: ""
|
|
type: "my_collection" # a collection in your site, in plural form
|
|
values:
|
|
layout: "default"
|
|
```
|
|
|
|
In this example, the `layout` is set to `default` inside the
|
|
[collection]({{ '/docs/collections/' | relative_url }}) with the name `my_collection`.
|
|
|
|
### Glob patterns in Front Matter defaults
|
|
|
|
It is also possible to use glob patterns (currently limited to patterns that contain `*`) when matching defaults. For example, it is possible to set specific layout for each `special-page.html` in any subfolder of `section` folder. {%- include docs_version_badge.html version="3.7.0" -%}
|
|
|
|
```yaml
|
|
collections:
|
|
my_collection:
|
|
output: true
|
|
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: "section/*/special-page.html"
|
|
values:
|
|
layout: "specific-layout"
|
|
```
|
|
|
|
<div class="note warning">
|
|
<h5>Globbing and Performance</h5>
|
|
<p>
|
|
Please note that globbing a path is known to have a negative effect on
|
|
performance and is currently not optimized, especially on Windows.
|
|
Globbing a path will increase your build times in proportion to the size
|
|
of the associated collection directory.
|
|
</p>
|
|
</div>
|
|
|
|
### Precedence
|
|
|
|
Jekyll will apply all of the configuration settings you specify in the `defaults` section of your `_config.yml` file. You can choose to override settings from other scope/values pair by specifying a more specific path for the scope.
|
|
|
|
You can see that in the second to last example above. First, we set the default page layout to `my-site`. Then, using a more specific path, we set the default layout for pages in the `projects/` path to `project`. This can be done with any value that you would set in the page or post front matter.
|
|
|
|
Finally, if you set defaults in the site configuration by adding a `defaults` section to your `_config.yml` file, you can override those settings in a post or page file. All you need to do is specify the settings in the post or page front matter. For example:
|
|
|
|
```yaml
|
|
# In _config.yml
|
|
...
|
|
defaults:
|
|
-
|
|
scope:
|
|
path: "projects"
|
|
type: "pages"
|
|
values:
|
|
layout: "project"
|
|
author: "Mr. Hyde"
|
|
category: "project"
|
|
...
|
|
```
|
|
|
|
```yaml
|
|
# In projects/foo_project.md
|
|
---
|
|
author: "John Smith"
|
|
layout: "foobar"
|
|
---
|
|
The post text goes here...
|
|
```
|
|
|
|
The `projects/foo_project.md` would have the `layout` set to `foobar` instead
|
|
of `project` and the `author` set to `John Smith` instead of `Mr. Hyde` when
|
|
the site is built.
|