From 11b4ae05e51d9d47693aeb1020dcb92d07575a03 Mon Sep 17 00:00:00 2001 From: Tom Johnson Date: Sun, 25 Dec 2016 20:33:09 -0800 Subject: [PATCH] Improve theme docs See https://github.com/jekyll/jekyll/pull/5630 for more details on the update. @jekyll/documentation @DirtyF --- docs/_docs/themes.md | 616 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 543 insertions(+), 73 deletions(-) diff --git a/docs/_docs/themes.md b/docs/_docs/themes.md index c7d6d574..31fdd457 100644 --- a/docs/_docs/themes.md +++ b/docs/_docs/themes.md @@ -1,110 +1,580 @@ --- layout: docs -title: Themes -permalink: /docs/themes/ +title: Templates +permalink: /docs/templates/ --- -Jekyll has an extensive theme system, which allows you to leverage community-maintained templates and styles to customize your site's presentation. Jekyll themes package layouts, includes, and stylesheets in a way that can be overridden by your site's content. +Jekyll uses the [Liquid](https://shopify.github.io/liquid/) templating language to +process templates. All of the standard Liquid [tags](https://shopify.github.io/liquid/tags/) and +[filters](https://shopify.github.io/liquid/filters/) are +supported. Jekyll even adds a few handy filters and tags of its own to make +common tasks easier. -## Installing a theme +## Filters -1. To install a theme, first, add the theme to your site's `Gemfile`: +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
DescriptionFilter and Output
+

Relative URL

+

Prepend the baseurl value to the input. Useful if your site is hosted at a subpath rather than the root of the domain.

+ 		+

+ {% raw %}{{ "/assets/style.css" | relative_url }}{% endraw %} +

+

+ /my-baseurl/assets/style.css +

+
+

Absolute URL

+

Prepend the url and baseurl value to the input.

+ 		+

+ {% raw %}{{ "/assets/style.css" | absolute_url }}{% endraw %} +

+

+ http://example.com/my-baseurl/assets/style.css +

+
+

Date to XML Schema

+

Convert a Date into XML Schema (ISO 8601) format.

+ 		+

+ {% raw %}{{ site.time | date_to_xmlschema }}{% endraw %} +

+

+ 2008-11-07T13:07:54-08:00 +

+
+

Date to RFC-822 Format

+

Convert a Date into the RFC-822 format used for RSS feeds.

+ 		+

+ {% raw %}{{ site.time | date_to_rfc822 }}{% endraw %} +

+

+ Mon, 07 Nov 2008 13:07:54 -0800 +

+
+

Date to String

+

Convert a date to short format.

+ 		+

+ {% raw %}{{ site.time | date_to_string }}{% endraw %} +

+

+ 07 Nov 2008 +

+
+

Date to Long String

+

Format a date to long format.

+ 		+

+ {% raw %}{{ site.time | date_to_long_string }}{% endraw %} +

+

+ 07 November 2008 +

+
+

Where

+

Select all the objects in an array where the key has the given value.

+ 		+

+ {% raw %}{{ site.members | where:"graduation_year","2014" }}{% endraw %} +

+
+

Where Expression

+

Select all the objects in an array where the expression is true. Jekyll v3.2.0 & later.

+ 		+

+ {% raw %}{{ site.members | where_exp:"item", +"item.graduation_year == 2014" }}{% endraw %} + {% raw %}{{ site.members | where_exp:"item", +"item.graduation_year < 2014" }}{% endraw %} + {% raw %}{{ site.members | where_exp:"item", +"item.projects contains 'foo'" }}{% endraw %} +

+
+

Group By

+

Group an array's items by a given property.

+ 		+

+ {% raw %}{{ site.members | group_by:"graduation_year" }}{% endraw %} +

+

+ [{"name"=>"2013", "items"=>[...]}, +{"name"=>"2014", "items"=>[...]}] +

+
+

Group By Expression

+

Group an array's items using a Liquid expression.

+ 		+

+ {% raw %}{{ site.members | group_by_exp:"item", +"item.graduation_year | truncate: 3, \"\"" }}{% endraw %} +

+

+ [{"name"=>"201...", "items"=>[...]}, +{"name"=>"200...", "items"=>[...]}] +

+
+

XML Escape

+

Escape some text for use in XML.

+ 		+

+ {% raw %}{{ page.content | xml_escape }}{% endraw %} +

+
+

CGI Escape

+

+ CGI escape a string for use in a URL. Replaces any special characters + with appropriate %XX replacements. +

+ 		+

+ {% raw %}{{ "foo,bar;baz?" | cgi_escape }}{% endraw %} +

+

+ foo%2Cbar%3Bbaz%3F +

+
+

URI Escape

+

+ URI escape a string. +

+ 		+

+ {% raw %}{{ "foo, bar \baz?" | uri_escape }}{% endraw %} +

+

+ foo,%20bar%20%5Cbaz? +

+
+

Number of Words

+

Count the number of words in some text.

+ 		+

+ {% raw %}{{ page.content | number_of_words }}{% endraw %} +

+

+ 1337 +

+
+

Array to Sentence

+

Convert an array into a sentence. Useful for listing tags. Optional argument for connector.

+ 		+

+ {% raw %}{{ page.tags | array_to_sentence_string }}{% endraw %} +

+

+ foo, bar, and baz +

+

+ {% raw %}{{ page.tags | array_to_sentence_string: 'or' }}{% endraw %} +

+

+ foo, bar, or baz +

+
+

Markdownify

+

Convert a Markdown-formatted string into HTML.

+ 		+

+ {% raw %}{{ page.excerpt | markdownify }}{% endraw %} +

+
+

Smartify

+

Convert "quotes" into “smart quotes.”

+ 		+

+ {% raw %}{{ page.title | smartify }}{% endraw %} +

+
+

Converting Sass/SCSS

+

Convert a Sass- or SCSS-formatted string into CSS.

+ 		+

+ {% raw %}{{ some_scss | scssify }}{% endraw %} + {% raw %}{{ some_sass | sassify }}{% endraw %} +

+
+

Slugify

+

Convert a string into a lowercase URL "slug". See below for options.

+ 		+

+ {% raw %}{{ "The _config.yml file" | slugify }}{% endraw %} +

+

+ the-config-yml-file +

+

+ {% raw %}{{ "The _config.yml file" | slugify: 'pretty' }}{% endraw %} +

+

+ the-_config.yml-file +

+
+

Data To JSON

+

Convert Hash or Array to JSON.

+ 		+

+ {% raw %}{{ site.data.projects | jsonify }}{% endraw %} +

+
+

Normalize Whitespace

+

Replace any occurrence of whitespace with a single space.

+ 		+

+ {% raw %}{{ "a \n b" | normalize_whitespace }}{% endraw %} +

+
+

Sort

+

Sort an array. Optional arguments for hashes: 1. property name 2. nils order (first or last).

+ 		+

+ {% raw %}{{ page.tags | sort }}{% endraw %} +

+

+ {% raw %}{{ site.posts | sort: 'author' }}{% endraw %} +

+

+ {% raw %}{{ site.pages | sort: 'title', 'last' }}{% endraw %} +

+
+

Sample

+

Pick a random value from an array. Optional: pick multiple values.

+ 		+

+ {% raw %}{{ site.pages | sample }}{% endraw %} +

+

+ {% raw %}{{ site.pages | sample:2 }}{% endraw %} +

+
+

To Integer

+

Convert a string or boolean to integer.

+ 		+

+ {% raw %}{{ some_var | to_integer }}{% endraw %} +

+
+

Array Filters

+

Push, pop, shift, and unshift elements from an Array.

+

These are NON-DESTRUCTIVE, i.e. they do not mutate the array, but rather make a copy and mutate that.

+ 		+

+ {% raw %}{{ page.tags | push: 'Spokane' }}{% endraw %} +

+

+ ['Seattle', 'Tacoma', 'Spokane'] +

+

+ {% raw %}{{ page.tags | pop }}{% endraw %} +

+

+ ['Seattle'] +

+

+ {% raw %}{{ page.tags | shift }}{% endraw %} +

+

+ ['Tacoma'] +

+

+ {% raw %}{{ page.tags | unshift: "Olympia" }}{% endraw %} +

+

+ ['Olympia', 'Seattle', 'Tacoma'] +

+
+

Inspect

+

Convert an object into its String representation for debugging.

+ 		+

+ {% raw %}{{ some_var | inspect }}{% endraw %} +

+
+
- gem 'my-awesome-jekyll-theme' +### Options for the `slugify` filter -2. Save the changes to your `Gemfile` -3. Run the command `bundle install` to install the theme -4. Finally, activate the theme by adding the following to your site's `_config.yml`: +The `slugify` filter accepts an option, each specifying what to filter. +The default is `default`. They are as follows (with what they filter): - theme: my-awesome-jekyll-theme +- `none`: no characters +- `raw`: spaces +- `default`: spaces and non-alphanumeric characters +- `pretty`: spaces and non-alphanumeric characters except for `._~!$&'()+,;=@` -You can have multiple themes listed in your site's Gemfile, but only one theme can be selected in your site's `_config.yml`. -{: .note .info } +## Tags -## Overriding theme defaults +### Includes -Jekyll themes set default layouts, includes, and stylesheets, that can be overridden by your site's content. For example, if your selected theme has a `page` layout, you can override the theme's layout by creating your own `page` layout in the `_layouts` folder (e.g., `_layouts/page.html`). +If you have small page fragments that you want to include in multiple places on your site, you can use the `include` tag: -Jekyll will look first to your site's content, before looking to the theme's defaults, for any requested file in the following folders: - -* `/assets` -* `/_layouts` -* `/_includes` -* `/_sass` - -Refer to your selected theme's documentation and source repository for more information on what files you can override. -{: .note .info} - -To locate theme's files on your computer, run `bundle show` followed by -the name of the theme's gem, e.g. `bundle show minima` for default Jekyll's -theme. Then copy the files you want to override, from the returned path to your root folder. - -## Creating a theme - -Jekyll themes are distributed as Ruby gems. Don't worry, Jekyll will help you scaffold a new theme with the `new-theme` command. Just run `jekyll new-theme` with the theme name as an argument: - -```sh -jekyll new-theme my-awesome-theme - create /path/to/my-awesome-theme/_layouts - create /path/to/my-awesome-theme/_includes - create /path/to/my-awesome-theme/_sass - create /path/to/my-awesome-theme/_layouts/page.html - create /path/to/my-awesome-theme/_layouts/post.html - create /path/to/my-awesome-theme/_layouts/default.html - create /path/to/my-awesome-theme/Gemfile - create /path/to/my-awesome-theme/my-awesome-theme.gemspec - create /path/to/my-awesome-theme/README.md - create /path/to/my-awesome-theme/LICENSE.txt - initialize /path/to/my-awesome-theme/.git - create /path/to/my-awesome-theme/.gitignore -Your new Jekyll theme, my-awesome-theme, is ready for you in /path/to/my-awesome-theme! -For help getting started, read /path/to/my-awesome-theme/README.md. +```liquid +{% raw %}{% include footer.html %}{% endraw %} ``` -Add your template files in the corresponding folders, complete the `.gemspec` and the README files according to your needs. +Jekyll expects all include files to be placed in an `_includes` directory at the root of your source directory. In the above example, this will embed the contents of `_includes/footer.html` into the calling file. -### Layouts and includes +For more advanced information on using includes, see [Includes](../includes). -Theme layouts and includes work just like they work in any Jekyll site. Place layouts in your theme's `/_layouts` folder, and place includes in your themes `/_includes` folder. +### Code snippet highlighting -For example, if your theme has a `/_layouts/page.html` file, and a page has `layout: page` in its YAML front matter, Jekyll will first look to the site's `_layouts` folder for a the `page` layout, and if none exists, will use your theme's `page` layout. +Jekyll has built in support for syntax highlighting of over 60 languages +thanks to [Rouge](http://rouge.jneen.net). Rouge is the default highlighter +in Jekyll 3 and above. To use it in Jekyll 2, set `highlighter` to `rouge` +and ensure the `rouge` gem is installed properly. -### Assets +Alternatively, you can use [Pygments](http://pygments.org) to highlight +your code snippets. To use Pygments, you must have Python installed on your +system, have the `pygments.rb` gem installed and set `highlighter` to +`pygments` in your site's configuration file. Pygments supports [over 100 +languages](http://pygments.org/languages/) -Any file in `/assets` will be copied over to the user's site upon build unless they have a file with the same relative path. You may ship any kind of asset here: SCSS, an image, a webfont, etc. These files behave just like pages and static files in Jekyll: if the file has [YAML front matter]({{ site.baseurl }}/docs/frontmatter/) at the top, then it will be rendered. If it does not have YAML front matter, it will simply be copied over into the resulting site. This allows theme creators to ship a default `/assets/styles.scss` file which their layouts can depend on as `/assets/styles.css`. +To render a code block with syntax highlighting, surround your code as follows: -All files in `/assets` will be output into the compiled site in the `/assets` folder just as you'd expect from using Jekyll on your sites. +```liquid +{% raw %} +{% highlight ruby %} +def foo + puts 'foo' +end +{% endhighlight %} +{% endraw %} +``` -### Stylesheets +The argument to the `highlight` tag (`ruby` in the example above) is the +language identifier. To find the appropriate identifier to use for the language +you want to highlight, look for the “short name” on the [Rouge +wiki](https://github.com/jayferd/rouge/wiki/List-of-supported-languages-and-lexers) +or the [Pygments' Lexers page](http://pygments.org/docs/lexers/). -Your theme's stylesheets should be placed in your theme's `/_sass` folder, again, just as you would when authoring a Jekyll site. Your theme's styles can be included in the user's stylesheet using the `@import` directive. +#### Line numbers -### Documenting your theme +There is a second argument to `highlight` called `linenos` that is optional. +Including the `linenos` argument will force the highlighted code to include line +numbers. For instance, the following code block would include line numbers next +to each line: -Your theme should include a `/README.md` file, which explains how site authors can install and use your theme. What layouts are included? What includes? Do they need to add anything special to their site's configuration file? +```liquid +{% raw %} +{% highlight ruby linenos %} +def foo + puts 'foo' +end +{% endhighlight %} +{% endraw %} +``` -### Adding a screenshot +#### Stylesheets for syntax highlighting -Themes are visual. Show users what your theme looks like by including a screenshot as `/screenshot.png` within your theme's repository where it can be retrieved programatically. You can also include this screenshot within your theme's documentation. +In order for the highlighting to show up, you’ll need to include a highlighting +stylesheet. For an example stylesheet you can look at +[syntax.css](https://github.com/mojombo/tpw/tree/master/css/syntax.css). These +are the same styles as used by GitHub and you are free to use them for your own +site. If you use `linenos`, you might want to include an additional CSS class +definition for the `.lineno` class in `syntax.css` to distinguish the line +numbers from the highlighted code. -### Previewing your theme +### Gist -To preview your theme as you're authoring it, it may be helpful to add dummy content in, for example, `/index.html` and `/page.html` files. This will allow you to use the `jekyll build` and `jekyll serve` commands to preview your theme, just as you'd preview a Jekyll site. +Use the `gist` tag to easily embed a GitHub Gist onto your site. This works +with public or secret gists: -If you do preview your theme locally, be sure to add `/_site` to your theme's `.gitignore` file to prevent the compiled site from also being included when you distribute your theme. -{: .info .note} +```liquid +{% raw %} +{% gist parkr/931c1c8d465a04042403 %} +{% endraw %} +``` -### Publishing your theme +You may also optionally specify the filename in the gist to display: -Themes are published via [RubyGems.org](https://rubygems.org). You'll need a RubyGems account, which you can [create for free](https://rubygems.org/sign_up). +```liquid +{% raw %} +{% gist parkr/931c1c8d465a04042403 jekyll-private-gist.markdown %} +{% endraw %} +``` -1. First, package your theme, by running the following command, replacing `my-awesome-jekyll-theme` with the name of your theme: +To use the `gist` tag, you'll need to add the +[jekyll-gist](https://github.com/jekyll/jekyll-gist) gem to your project. - gem build my-awesome-jekyll-theme.gemspec +## Links -2. Next, push your packaged theme up to the RubyGems service, by running the following command, again replacing `my-awesome-jekyll-theme` with the name of your theme: +### Linking to pages {#link} - gem push my-awesome-jekyll-theme-*.gem +To link to a post, a page, collection item, or file, the `link` tag will generate the correct permalink URL for the path you specify. For example, if you use the `link` tag to link to `mypage.html`, even if you change your permalink style to include the file extension or omit it, the URL formed by the `link` tag will always be valid. -3. To release a new version of your theme, simply update the version number in the gemspec file, ( `my-awesome-jekyll-theme.gemspec` in this example ), and then repeat Steps 1 & 2 above. -We recommend that you follow [Semantic Versioning](http://semver.org/) while bumping your theme-version. +You must include the file's original extension when using the `link` tag. Here are some examples: + +```liquid +{% raw %} +{{ site.baseurl }}{% link _collection/name-of-document.md %} +{{ site.baseurl }}{% link _posts/2016-07-26-name-of-post.md %} +{{ site.baseurl }}{% link news/index.html %} +{{ site.baseurl }}{% link /assets/files/doc.pdf %} +{% endraw %} +``` + +You can also use the `link` tag to create a link in Markdown as follows: + +```liquid +{% raw %} +[Link to a document]({{ site.baseurl }}{% link _collection/name-of-document.md %}) +[Link to a post]({{ site.baseurl }}{% link _posts/2016-07-26-name-of-post.md %}) +[Link to a page]({{ site.baseurl }}{% link news/index.html %}) +[Link to a file]({{ site.baseurl }}{% link /assets/files/doc.pdf %}) +{% endraw %} +``` + +Including `{% raw %}{{site.baseurl}}{% endraw %}` is optional — it depends on whether you want the link to be absolute or root-relative. + +The path to the post, page, or collection is defined as the path relative to the root directory (where your config file is) to the file, not the path from your existing page to the other page. + +For example, suppose you're creating a link `page_a.md` (stored in `pages/folder1/folder2`) to `page_b.md` (stored in `pages/folder1`). Your path in the link would not be `../page_b.html`. Instead, it would be `/pages/folder1/page_b.md`. + +If you're unsure of the path, add `{% raw %}{{page.path}}{% endraw %}` to the page and it will display the path. + +One major benefit of using the `link` tag is link validation. If the link doesn't exist, Jekyll won't build your site. This is a good thing, as it will alert you to a broken link so you can fix it (rather than allowing you to build and deploy a site with broken links). + +Note you cannot add filters to `link` tags. For example, you cannot append a string using Liquid filters, such as `{% raw %}{% link mypage.html | append: "#section1" %} {% endraw %}`. To link to sections on a page, you will need to use regular HTML or Markdown linking techniques. + +### Linking to posts + +If you want like to include a link to a post on your site, the `post_url` tag will generate the correct permalink URL for the post you specify. + +```liquid +{% raw %} +{{ site.baseurl }}{% post_url 2010-07-21-name-of-post %} +{% endraw %} +``` + +If you organize your posts in subdirectories, you need to include subdirectory path to the post: + +```liquid +{% raw %} +{{ site.baseurl }}{% post_url /subdir/2010-07-21-name-of-post %} +{% endraw %} +``` + +There is no need to include the file extension when using the `post_url` tag. + +You can also use this tag to create a link to a post in Markdown as follows: + +```liquid +{% raw %} +[Name of Link]({{ site.baseurl }}{% post_url 2010-07-21-name-of-post %}) +{% endraw %} +```