vuepress/docs/theming.md

Custom Themes

VuePress uses Vue single file components for custom themes. To use a custom layout, create a .vuepress/theme directory in your docs root, and then create a Layout.vue file:

.
└── .vuepress
    └── theme
        └── Layout.vue

From there it's the same as developing a normal Vue application. It is entirely up to you how to organize your theme.

Using Theme from a Dependency

Themes can be published on npm as vuepress-theme-xxx.

To use a theme from an npm dependency, provide a theme option in .vuepress/config.js:

module.exports = {
  theme: 'awesome'
}

VuePress will attempt to locate and use node_modules/vuepress-theme-awesome/Layout.vue.

Content Outlet

The compiled content of the current .md file being rendered will be available as a special <Content/> global component. You will need to render it somewhere in your layout in order to display the content of the page. The simplest theme can be just a single Layout.vue component with the following content:

<template>
  <div class="theme-container">
    <Content/>
  </div>
</template>

In addition to rendering the markdown content, the <Content/> component is also responsible for setting the title and other metadata of a specific page.

Site and Page Metadata

The Layout component will be invoked once for every .md file in docs, and the metadata for the entire site and that specific page will be exposed respectively in $site and $page properties which are injected into every component in the app.

This is the value of $site of this very website:

{
  "title": "VuePress",
  "description": "Minimalistic docs generator with Vue component based layout system",
  "base": "/vuepress/",
  "pages": [
    {
      "path": "/",
      "title": "VuePress",
      "frontmatter": {}
    },
    ...
  ]
}

title, description and base are copied from respective fields in .vuepress/config.js. pages contains an array of metadata objects for each page, including its path, page title (explicitly specified in YAML frontmatter or inferred from the first header on the page), and any YAML frontmatter data in that file.

This is the $page object for this page you are looking at:

{
  "path": "/theming.html",
  "title": "Custom Theme",
  "frontmatter": {}
}

If the user provided themeConfig in .vuepress/config.js, it will also be available as $site.themeConfig. You can use this to allow users to customize behavior of your theme - for example, specifying categories and page order. You can then use these data together with $site.pages to dynamically construct navigation links.