hexo-theme-icarus/source/_posts/en/Configuring-Theme.md

title: Icarus User Guide - Configuring the Theme
date: 2020-03-01
categories:
- Configuration
tags:
- Getting Started
- Icarus User Guide
language: en
toc: true
cover: /gallery/covers/vector_landscape_2.svg
thumbnail: /gallery/covers/vector_landscape_2.svg
---

Icarus' default theme configuration file is `_config.icarus.yml`.
It defines the global layout and style settings of the theme and controls external features such as plugins and widgets.
This article details the general configurations of the theme.
It also explains what configuration files are used and how Icarus generate and validate these configurations.

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## General Theme Configurations

### Configuration Version

This version code is related to and but not always the same as the theme version code.
Icarus uses it to determine whether to upgrade the default theme configuration file.
You should not change it by yourself.

{% codeblock _config.icarus.yml lang:yaml %}
version: 4.0.0
{% endcodeblock %}

### Theme Variant

Choose a skin for Icarus.
`"default"` and `"cyberpunk"` are supported values currently.
You can take a look at the Cyberpunk variant {% post_link demo/Cyberpunk "here" %}.

{% codeblock _config.icarus.yml lang:yaml %}
variant: default
{% endcodeblock %}

### Logo

Set the logo of your site.
It will display on the navigation bar and the footer.
The value of the `logo` can either be the path or URL to your logo image:

{% codeblock _config.icarus.yml lang:yaml %}
logo: /img/logo.svg
{% endcodeblock %}

or text if you set it like the following:

{% codeblock _config.icarus.yml lang:yaml %}
logo:
    text: My Beautiful Site
{% endcodeblock %}

### Favicon

You can specify the path or URL to your site's favicon in the `head` section.

{% codeblock _config.icarus.yml lang:yaml %}
head:
    favicon: /img/favicon.svg
{% endcodeblock %}

### Open Graph

You can set up Open Graph in the `head` section.
You should leave most of the settings blank in the configuration file.
Only set those settings in the front-matter of your post if you need them.
Please refer to [Hexo documentation](https://hexo.io/docs/helpers.html#open-graph) for details on each setting.

{% codeblock _config.icarus.yml lang:yaml >folded %}
head:
    open_graph:
        # Page title (og:title) (optional)
        # You should leave this blank for most of the time
        title: 
        # Page type (og:type) (optional)
        # You should leave this blank for most of the time
        type: blog
        # Page URL (og:url) (optional)
        # You should leave this blank for most of the time
        url: 
        # Page cover (og:image) (optional)
        # You should leave this blank for most of the time
        image: 
        # Site name (og:site_name) (optional)
        # You should leave this blank for most of the time
        site_name: 
        # Page author (article:author) (optional)
        # You should leave this blank for most of the time
        author: 
        # Page description (og:description) (optional)
        # You should leave this blank for most of the time
        description: 
        # Twitter card type (twitter:card)
        twitter_card: 
        # Twitter ID (twitter:creator)
        twitter_id: 
        # Twitter Site (twitter:site)
        twitter_site: 
        # Google+ profile link (deprecated)
        google_plus: 
        # Facebook admin ID
        fb_admins: 
        # Facebook App ID
        fb_app_id: 
{% endcodeblock %}

### Google Structured Data

You can set up Google Structured Data in the `head` section.
You should leave most of the settings blank in the configuration file.
Only set those settings in the front-matter of your post if you need them.
Please refer to [Search for Developers](https://developers.google.com/search/docs/guides/intro-structured-data) 
for details on each setting.

{% codeblock _config.icarus.yml lang:yaml >folded %}
head:
    structured_data:
        # Page title (optional)
        # You should leave this blank for most of the time
        title: 
        # Page description (optional)
        # You should leave this blank for most of the time
        description: 
        # Page URL (optional)
        # You should leave this blank for most of the time
        url: 
        # Page author (article:author) (optional)
        # You should leave this blank for most of the time
        author: 
        # Page images (optional)
        # You should leave this blank for most of the time
        image: 
{% endcodeblock %}

### Page Metadata

You can add custom `<meta>` tags to the generated HTML from the `meta` setting in the `head` section.
Each meta tag should appear as an item of the `meta` array.
The value of each `meta` item should be in the `<field_name>=<field_value>` format 
with `field_name` and `field_value` represent the field and value of the `<meta>` tag respectively.
Separate the `<field_name>=<field_value>` pairs with `;` if the `<meta>` tag has multiple fields and values.

{% codeblock _config.icarus.yml lang:yaml %}
head:
    meta:
        - 'name=theme-color;content=#123456'
        - 'name=generator;content="Hexo 4.2.0"'
{% endcodeblock %}

### RSS

You can add a link to your RSS feed at the `rss` setting in the `head` section.

{% codeblock _config.icarus.yml lang:yaml %}
head:
    rss: /path/to/atom.xml
{% endcodeblock %}

### Navigation Bar

The `navbar` section defines the menu items and links in the navigation bar.
You may put any menu item in the navigation bar by adding `<link_name>: <link_url>` to the `menu` setting.
To put links on the right side of the navigation bar, add `<link_name>: <link_url>` to the `links` setting.

{% codeblock _config.icarus.yml lang:yaml %}
navbar:
    # Naviagtion menu items
    menu:
        Home: /
        Archives: /archives
        Categories: /categories
        Tags: /tags
        About: /about
    # Links to be shown on the right of the navigation bar
    links:
        GitHub: 'https://github.com'
        Download on GitHub:
            icon: fab fa-github
            url: 'https://github.com/ppoffice/hexo-theme-icarus'
{% endcodeblock %}

You can display a FontAwesome icon instead of text-only link with the following format:

{% codeblock "Link format" lang:yaml %}
<link_name>:
    icon: <fontawesome_icon_class_name>
    url: <link_url>
{% endcodeblock %}

### Footer

The `footer` section defines the links on the right side of the page footer.
The link format is exactly the same as `links` in the `navbar` section.

{% codeblock _config.icarus.yml lang:yaml %}
footer:
    links:
        Creative Commons:
            icon: fab fa-creative-commons
            url: 'https://creativecommons.org/'
        Attribution 4.0 International:
            icon: fab fa-creative-commons-by
            url: 'https://creativecommons.org/licenses/by/4.0/'
        Download on GitHub:
            icon: fab fa-github
            url: 'https://github.com/ppoffice/hexo-theme-icarus'
{% endcodeblock %}

### Code Highlight

If you have enabled code highlighting in Hexo, you can customize the code blocks with `highlight` settings 
in the `article` section.
Choose a theme from all themes listed under 
[highlight.js/src/styles](https://github.com/highlightjs/highlight.js/tree/9.18.1/src/styles).
Then, copy the file name (without the `.css` extension) to the `theme` setting.

To hide the "copy" button of every code block, set `clipboard` to `false`.
If you wish to fold or unfold all code blocks, set the `fold` setting to `"folded"` or `"unfolded"`.
You can also disable the folding feature by leaving the `fold` setting empty.

{% codeblock _config.icarus.yml lang:yaml %}
article:
    highlight:
        # Code highlight themes
        # https://github.com/highlightjs/highlight.js/tree/master/src/styles
        theme: atom-one-light
        # Show copy code button
        clipboard: true
        # Default folding status of the code blocks. Can be "", "folded", "unfolded"
        fold: unfolded
{% endcodeblock %}

Additionally, you can fold an individual code block in the Markdown file using the following syntax:

```
{% codeblock "optional file name" lang:code_language_name >folded %}
...code block content...
{% endcodeblock %}
```

### Cover & Thumbnail

You can add a cover image to your post by adding the `cover` property in post's front-matter:

{% codeblock post.md lang:yaml %}
title: Getting Started with Icarus
cover: /gallery/covers/cover.jpg
---
Post content...
{% endcodeblock %}

Similarly, you may set the thumbnail of your post in the front-matter as well:

{% codeblock post.md lang:yaml %}
title: Getting Started with Icarus
thumbnail: /gallery/thumbnails/thumbnail.jpg
---
Post content...
{% endcodeblock %}

The thumbnail will show in the archive page as well as in the recent post widget.

If you choose to use the image path in the front-matter, you need to ensure the path is absolute
or relative to the source directory of your site.
For example, to use `<your blog>/source/gallery/image.jpg` as a thumbnail image, you need to put
`thumbnail: /gallery/image.jpg` in the front-matter.

### Read Time

You can show a word counter and the estimated reading time of your article above the article title by 
setting `readtime` to `true` in the `article` section.

{% codeblock _config.icarus.yml lang:yaml %}
article:
    readtime: true
{% endcodeblock %}

### Article Licensing

You can show a section at the end of your posts/pages describing the licensing of your work.
Both text and icons are accepted as license links.
This configuration is the same as `links` in the navigation bar or the footer:

{% codeblock _config.icarus.yml lang:yaml %}
article:
    # Article licensing block
    licenses:
        Creative Commons:
            icon: fab fa-creative-commons
            url: 'https://creativecommons.org/'
        'CC BY-NC-SA 4.0': 'https://creativecommons.org/licenses/by-nc-sa/4.0/'
{% endcodeblock %}

### Sidebar

To make a sidebar fixed when you scroll the page, set the `sticky` setting of that sidebar to `true` in
the `sidebar` section.

{% codeblock _config.icarus.yml lang:yaml %}
sidebar:
    left:
        sticky: false
    right:
        sticky: true
{% endcodeblock %}


### Other Configurations

You can refer to the [Icarus User Guide](/hexo-theme-icarus/tags/Icarus-User-Guide/) to learn more about 
third-party plugins, widgets, and CDN provider configurations.


## Configuration Files and Priority

Apart from the default theme configuration file `_config.icarus.yml`, Icarus also looks at the following
locations for alternative configurations:

- The site configuration file at `_config.yml`
- Layout configuration files at `_config.post.yml` and `_config.page.yml`
- Post/page's [front-matter](https://hexo.io/docs/front-matter.html)
- (Deprecated) Legacy theme configuration file at `themes/icarus/_config.yml`
- (Deprecated) Legacy layout configuration file at `themes/icarus/_config.post.yml` and `themes/icarus/_config.page.yml`

### Layout Configuration Files

Layout configuration files follow the same format and definitions as theme configuration files.
The configurations in `_config.post.yml` apply to all posts, and those in `_config.page.yml` apply to all custom pages.
They both override configurations in theme configuration files.

For example, you can adopt a two-column layout for all posts in `_config.post.yml`:

{% codeblock _config.post.yml lang:yaml %}
widgets:
    -
        type: recent_posts
        position: left
    -
        type: categories
        position: left
    -
        type: tags
        position: left
{% endcodeblock %}

while keeping a three-column layout in all other pages:

{% codeblock _config.icarus.yml lang:yaml %}
widgets:
    -
        type: recent_posts
        position: left
    -
        type: categories
        position: right
    -
        type: tags
        position: right
{% endcodeblock %}

### Post/Page Front-matter

If you wish to override theme configurations only for a certain post/page, you can set them in the front-matter 
of that post/page.
For example, you can change the code block highlight theme of a single post by setting it in that post's
front-matter like the following:

{% codeblock source/_post/some-post.md lang:yaml %}
title: My first post
date: '2015-01-01 00:00:01'
article:
    highlight:
        theme: atom-one-dark
---
# Some Post
{% endcodeblock %}

The above setting will always override the `article.highlight` in `_config.post.yml` and `_config.icarus.yml`
for that post.
This layered configuration scheme is handy for differentiating page customizations and optimizations 
for different audiences.
For instance, you can enable faster CDNs or a localized comment service based on the country and language 
of your page viewers.

However, it should be noted that post or page attributes defined by Hexo will not override the theme 
configurations from the front-matter.
Examples are `title`, `date`, `updated`, `comments`, `layout`, `source`, `photos`, and `excerpt`.

### Site Configuration File

All configuration sources listed above, including theme configuration files, layout configuration files, 
and post/page front-matter, will override the site configuration file only for configurations
used by Icarus.
For instance, `title` in the `_config.icarus.yml` will override `title` in the `_config.yml`, but
`new_post_name` will not since it is not used by Icarus.

Also, the `theme_config` option in the site configuration file will merge with and override theme
configurations from theme configuration files.
However, using this option is highly discouraged.

### Conclusion

In conclusion, the scopes of the configuration sources and their priorities are:

- For a certain post or page

    - Post/Page front-matter overrides all following sources.
    - Layout configuration files override all following sources.
    - `theme_config` option in the site configuration file overrides all following sources.
    - Theme configuration files override all following sources.
    - The site configuration file.

- For all posts or pages

    - Layout configuration files override all following sources.
    - `theme_config` option in the site configuration file overrides all following sources.
    - Theme configuration files override all following sources.
    - The site configuration file.

- For all posts, pages, and index pages

    - `theme_config` option in the site configuration file overrides all following sources.
    - Theme configuration files override all following sources.
    - The site configuration file.


## Configuration Generation and Validation

All Icarus theme configurations are written in [YAML language](https://yaml.org/).
Icarus will automatically generate the default configuration file `_config.icarus.yml` from a set of 
[JSON schemas](https://json-schema.org/) if it does not exist.
That's why you don't see an example configuration file (such as `_config.yml.example`) under the theme directory.
Most of the JSON schemas are in the `<icarus_directory>/include/schema` directory, while the others are
in the [ppoffice/hexo-component-inferno](https://github.com/ppoffice/hexo-component-inferno) repository.
You can attach the `--icarus-dont-generate-config` flag to your `hexo` commands to prevent automatic configuration
generation.

The theme also validates your configurations against these schemas every time you execute a `hexo` command.
If anything goes wrong during the validation, Icarus will print out the exact location of the misconfiguration
and its error type.
For example, the following messages tell us that the value of the `logo` setting should be either a string or an 
object, instead of an integer.
You may skip the validation by appending the `--icarus-dont-check-config` flag to your `hexo` commands, but it is 
not recommended to do so.

{% codeblock "hexo log" %}
INFO  === Checking package dependencies ===
INFO  === Checking the configuration file ===
WARN  Configuration file failed one or more checks.
WARN  Icarus may still run, but you will encounter unexcepted results.
WARN  Here is some information for you to correct the configuration file.
WARN  [
  {
    keyword: 'type',
    dataPath: '.logo',
    schemaPath: '#/properties/logo/type',
    params: { type: 'string,object' },
    message: 'should be string,object'
  }
]
{% endcodeblock %}

Additionally, Icarus will execute migration scripts to upgrade the default theme configuration file to the newest 
version if it is not.
These scripts are in the `<icarus_directory>/include/migration` directory.
You may disable the upgrade by appending the `--icarus-dont-upgrade-config` flag to your `hexo` commands.
Finally, Icarus will also check the Node.js package dependencies and remind you to install them if you haven't.


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