gatsby-theme-blog

The Gatsby Blog theme

A Gatsby theme for creating a blog.

Installation

For a new site

If you're creating a new site and want to use the blog theme, you can use the blog theme starter. This will generate a new site that pre-configures use of the blog theme.

gatsby new my-themed-blog https://github.com/gatsbyjs/gatsby-starter-blog-theme

For an existing site

If you already have a site you'd like to add the blog theme to, you can manually configure it.

1. Install the blog theme

npm install gatsby-theme-blog

1. Add the configuration to your gatsby-config.js file

// gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-theme-blog`,
      options: {
        // basePath defaults to `/`
        basePath: `/blog`,
      },
    },
  ],
}

1. Add blog posts to your site by creating md or mdx files inside /content/posts.

   Note that if you've changed the default contentPath in the configuration, you'll want to add your markdown files in the directory specified by that path.

2. Add an image with the file name avatar (can be jpg or png) inside the /assets directory to include a small image next to the footer on every post page.

   Note that if you've changed the default assetPath in the configuration, you'll want to add your asset files in the directory specified by that path.

3. Run your site using gatsby develop and navigate to your blog posts. If you used the above configuration, your URL will be http://localhost:8000/blog

Usage

Theme options

Key	Default value	Description
basePath	/	Root url for all blog posts
contentPath	content/posts	Location of blog posts
assetPath	content/assets	Location of assets
mdxOtherwiseConfigured	false	Set this flag true if gatsby-plugin-mdx is already configured for your site.
preset	gatsby-theme-ui-preset	Theme UI compatible package name that will act as the base styles for your project. Be sure to install the package you're referencing. Set to false to ignore all presets and only use local styles.
prismPreset	null	Theme UI compatible package name that will act as the prism syntax highlighting for your project. Be sure to install the package you're referencing. For themes in @theme-ui/prism the name will suffice, e.g. prism-okaidia.
excerptLength	140	Length of the auto-generated excerpt of a blog post
webfontURL	''	URL for the webfont you'd like to include. Be sure that your local theme does not override it.
imageMaxWidth	1380	Set the max width of images in your blog posts. This applies to your featured image in frontmatter as well.
filter	{}	Set the posts filter, for example: { frontmatter: { draft: {ne: true} } }
limit	1000	Set the amount of pages that should be generated

Example configuration

// gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-theme-blog`,
      options: {
        // basePath defaults to `/`
        basePath: `/blog`,
        prismPreset: `prism-okaidia`,
      },
    },
  ],
}

Additional configuration

In addition to the theme options, there are a handful of items you can customize via the siteMetadata object in your site's gatsby-config.js

// gatsby-config.js
module.exports = {
  siteMetadata: {
    // Used for the site title and SEO
    title: `My Blog Title`,
    // Used to provide alt text for your avatar
    author: `My Name`,
    // Used for SEO
    description: `My site description...`,
    // Used for resolving images in social cards
    siteUrl: `https://example.com`,
    // Used for social links in the root footer
    social: [
      {
        name: `Twitter`,
        url: `https://twitter.com/gatsbyjs`,
      },
      {
        name: `GitHub`,
        url: `https://github.com/gatsbyjs`,
      },
    ],
  },
}

Blog Post Fields

The following are the defined blog post fields based on the node interface in the schema

Field	Type
id	String
title	String
body	String
slug	String
date	Date
tags	String[]
excerpt	String
image	String
imageAlt	String
imageCaptionText	String
imageCaptionLink	String
socialImage	String

Image Behavior

Blog posts can include references to images inside frontmatter. Note that this works for a relative path as shown below, or an external URL.

---
title: Hello World (example)
date: 2019-04-15
image: ./some-image.jpg
---

image refers to the featured image at the top of a post and is not required. It will also appear as the preview image inside a social card. Note that this requires you to set siteUrl in your gatsby-config.js file metadata to your site's domain.

When adding an image, imageAlt is available to provide alt text for the featured image within the post. If this is not included, it defaults to the post excerpt.

You may want to use a different image for social sharing than the one that appears in your blog post. You can do so by setting socialImage in frontmatter.

How Styles work

This theme enables gatsby-plugin-theme-ui which allows you to leverage Theme UI to style your project.

By default, gatsby-theme-ui-preset operates as your base theme styles. Any local shadowed styles deep merge with that preset.

Alternatively, you can pass a preset of your own choosing by installing the package and passing the package name as the preset in gatsby-config.js. Again, local shadowed styles will deep merge with this preset if they exist.

// gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-theme-blog`,
      options: {
        preset: `my-preset-name-here`,
      },
    },
  ],
}

If you'd rather use only local shadowed styles with no underlying preset, pass the preset option as false.

Prism

You can also configure your prism theme for syntax highlighting in code snippets by passing the prismPreset option.

@theme-ui/prism is included by default, so any available presets can be passed using only their name, e.g. dracula.

// gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-theme-blog`,
      options: {
        prismPreset: `dracula`,
      },
    },
  ],
}

As an alternative, you can install a package with a prism theme into your project and pass the package name.

This option is null by default, and in all cases local shadowed styles take precedent.

Highlight Line

You can highlight code snippets using // highlight line or a combination of // highlight-start and // highlight-end.

To update the styling for these highlights override the .highlight styles inside your prism theme.

Accessibility and skip-nav

This theme comes equipped with skip-nav. Note that if you override header.js you'll need to add the SkipNavLink component yourself. Additionally, if you override layout.js you'll need to include SkipNavContent manually.

Migration

For migration guides please see the dedicated migration guide.