This guide is for Gatsby Version 2.

Table of Contents

Introduction

Gatsby is technically a Static Site Generator (SSG) which allows you to build incredibly fast websites using React. I say technically because you aren't truly limited to static, client side rendered (CSR) sites. Gatsby is more of a hybrid, allowing you to use dynamic content, connect to a Content Management System (CMS), utilize server side rendering (SSR) and more. In this guide, we're going to focus on just the static site part. Also, Gatsby uses GraphQL which will be covered in this guide.

If you follow along you'll be able to go from an empty folder to a fully functioning Gatsby site, while understanding how it all works under the hood.

Installing and Setting Up Gatsby

I recommend starting with an empty file and following along to get the most out of this guide. But, if you just want the completed project, it can be found in the repository's master branch.

Gatsby has an a huge amount of incredibly useful plugins. The plugins can be broken down into three main categories: transformer, functional, and source.

Transformer plugins take data that isn't usable in its current form, such as markdown or json, and transforms it into a format that can be queried against with GraphQL. We will be using gatsby-transformer-remark to transform Markdown files into HTML.

Functional plugins either implement functionality, such as manifest generation or offline support, or they extend Gatsby functionality, like adding Typescript support. One functional plugin we'll be using is gatsby-plugin-catch-links , which intercepts local links and replaces the link behavior with Gatsby's Link. This avoids having the browser refresh the page and as a result, allowing for page changes without reload.

Source plugins create nodes which is the center of Gatsby's data system, and transform data into a usable format. We'll be using gatsby-source-filesystem which loads files of off the disk allowing the transformer plugins to transform the data.

To start, install the dependencies with npm i react react-dom gatsby gatsby-source-filesystem gatsby-transformer-remark gatsby-plugin-catch-links .

Next create the gatsby-config.js file and enter the site metadata. Make sure the file is in the root of the project, not in /src.

module . exports = { siteMetadata : { title : 'Gatsby Tutorial Site' , description : 'Welcome to your brand new Gatsby V2 Website.' } , }

Creating the Layout Page

Let's create a layout component. It will include the features that we want rendered on all pages, such as the header, the footer, etc. Create the folder layouts and in it index.jsx . We need to pass the {children} so that whatever we put in our components gets rendered down the line.

import React from 'react' export default ( { children } ) => ( < div > < h3 > Gatsby Tutorial </ h3 > { children } </ div > )

Now let's fill out the main page with a basic export.

import React from 'react' export default ( ) => ( < div > < h1 > Gatsby Tutorial Site Home Page </ h1 > < p > This is the home page. </ p > </ div > )

And finally we'll make an about page.

import React from 'react' export default ( ) => ( < div > < h1 > About </ h1 > < p > This is the about page. </ p > </ div > )

Here's a really cool feature of Gatsby. Routing is done using @reach/router under the hood. Keeping things simple, all we have to do is import Link from Gatsby and use the Link component with the desired path. Let's go into the Layout component and do that now.

import React from 'react' import { Link } from 'gatsby' export default ( { children } ) => ( < div > < Link to = { '/' } > < h3 > Gatsby Tutorial </ h3 > </ Link > < Link to = { '/about' } > About </ Link > { children } </ div > )

Using GraphiQL to View and Build Queries

Gatsby uses GraphQL, which is a Querying Language that allows access data data through simple declarative expressions. One major benefit of GraphQL is that it eliminates a lot of bloat. It allows you to be specific and receive only the data you need. We can take a look at all the queries that are available by using a tool called GraphiQL. We can access it by starting the dev server with gatsby develop , and then opening localhost:8000/___graphql.

Now that we have GraphiQL open in the browser, open up the Documentation Explorer and look through the schema and see what queries we can make. Click on the QueryType and we see a big list of eveything available. Since we've already entered the site metadata, let's see how to query it. Look at the site query and we see that the first key that's listed is siteMetadata . If we enter that query and click run:

{ site { siteMetadata } }

We'll see the output:

{ "data" : { "site" : { "siteMetadata" : { "title" : "Gatsby Tutorial Site" , "description" : "Welcome to your brand new Gatsby V2 Website." , } } } }

We see title and description . These will update if we make changes to the gatsby-config.js file. Let's try that. We'll add author: "Justin" under the "description." Let's save it, restart the dev server, and reload the GraphiQL explorer. And author is now a field.

GraphQL Query

Sticking to React's paradigm of reusable components, we have a chance to reuse a bit of data. Notice how in both the index and the about page have similar titles? When building sites, there will be plenty of instances where being able to reuse data is ideal, avoiding having to type the same thing over and over again.

Also, what if we wanted to change the title, or any other data in the future? We'd have to go through every page and manually change it. The more complex your site becomes, the more "going back and changing stuff" becomes a burden. Let's make this as pain free as possible by using GraphQL. We'll have our title come from one single location, the gatsby-config.js we've already written.

To query it, we have two options as of Gatsby v2, page query and StaticQuery . StaticQuery can be used in any page or component, but variables can't be passed to them, hence the "static" name. Page queries on the other hand, can only be used in pages, but you're allowed to pass query variables to them.

Page Query

First we'll use the page query. Since we've already looked at the GraphiQL explorer, we know what our query should look like.

import React from 'react' import { graphql } from 'gatsby' import Layout from '../layouts' export default ( { data } ) => ( < Layout > < h1 > { data . site . siteMetadata . title } About Page </ h1 > < p > This is the about page. </ p > </ Layout > ) export const query = graphql ` query AboutQuery { site { siteMetadata { title } } } `

And if we check the about page, the title is right there.

Static Query

Let's test out StaticQuery now. Since it can be used on non-page components, let's add it to the Layout. First we need to import StaticQuery and grapqhl, and return the component.

It accepts two props, query and render . The query prop takes a a tagged template literal, which allow embedded expressions. The render prop takes a function with data as a single argument. The data is the query results.

import React from 'react' import { graphql , StaticQuery , Link } from 'gatsby' export default ( { children } ) => ( < StaticQuery query = { graphql ` query { site { siteMetadata { title } } } ` } render = { data => ( < div > < Link to = { '/' } > < h3 > { data . site . siteMetadata . title } </ h3 > </ Link > < Link to = { '/about' } > About </ Link > { children } </ div > ) } / > )

Formatting Markdown Files

Now we're going to go a little further in utilizing GraphQL and make some posts. We can keep our markdown files in a separate directory outside of /src. It makes it easier to look at and find files, especially when we start adding photos. Let's mkdir content/posts and then create a different folder for individual posts. With those made, make an index.md in each folder. Inside each index.md file, we'll create our post. The important part to take note of is the set of three dashes. That is the "frontmatter", and the contents of the block will be the data that we can pass into our pages and templates later on.

--- path: "/post-one" date: "2018-10-15" title: "My First Post" tags: ['gatsby', 'other'] --- This is my first post using Gatbsy.

Now go back to the gatsy-config.js file and add add the plugins we installed before.

module . exports = { siteMetadata : { title : 'Gatsby Tutorial Site' , description : 'Welcome to your brand new Gatsby V2 Website.' } , plugins : [ 'gatsby-plugin-catch-links' , 'gatsby-transformer-remark' , { resolve : 'gatsby-source-filesystem' , options : { name : 'posts' , path : ` ${ __dirname } /content/posts` } } ] }

Make sure the "path:" is set to where your markdown files are located.

Let's go back to our GraphiQL explorer and see the newly added allMarkdownRemark . Click on MarkdownRemarkConnection and we'll see all of the fields. We see edges , which are the filepaths. Click on the [MarkdownRemarkEdge] next to the edge field and we'll see node up at the top, which is each of our markdown files we created. Inside of node we see that frontmatter is a field, which is what encompasses what is in our markdown files.

{ allMarkdownRemark { edges { node { frontmatter } } } }

Run the query and see all that data that frontmatter has. We can get more specific and query a single field, such as the title, and get only that result. So we just made use of the transformer plugin, and we saw it "transform" the content onto our page. There are around 500 plugins at the time of writing this and we'll be using more to do various things later on.

Creating A List of Markdown Files

Now let's make a list of our markdown files. We'll be using GraphQL to query our content and render it on a page. First, let's go back to our index page and import graphql and then write out the query. What we enter into our query will be exactly what data gets passing into the component.

To pass the data into the component, we'll pass data and destructure edges as data.allMarkdownRemark, map over it to get the post fields, and then add each field that we entered in our query.

Let's keep the id, and with it we'll specify the key. Each child component as well as each element inside the child should have keys. React uses the keys to determine the identity of the rendered elements. This is important for minimizing DOM manipulation, leading to better performance. To learn more, start at the Official React Docs about lists and keys and go from there.

After that, just fill out the information that we queried. Side note: the field excerpt lives on the node , and takes two arguments - pruneLength , an integer and truncate , a boolean. We'll prune it and play with the length until it feels right.

import React from 'react' import { graphql } from 'gatsby' import Layout from '../layouts' export default ( { data } ) => { const { edges } = data . allMarkdownRemark return ( < Layout > < h1 > Gatsby Tutorial Site Home Page </ h1 > { edges . map ( ( { node } ) => ( < div key = { node . id } > < h3 > { node . frontmatter . title } { " " } </ h3 > < p > { node . frontmatter . date } </ p > < p > { node . excerpt } </ p > </ div > ) ) } </ Layout > ) } export const query = graphql ` query { allMarkdownRemark { edges { node { id excerpt(pruneLength:100) frontmatter { title date } } } } } `

The list of our posts should now be on the home page.

Filtering and Sorting Markdown Files

Now that we have a list of our posts, let's organize them.

Sorting

Let's first make sure that the newest post is always on top. Go back to our GraphiQL explorer and look at allMarkdownRemark, we'll see that it can take some arguments. Click on sort , and we see both fields and order . Checking order , we see ASC and DESC for ascending and descending. Clicking on fields we see a whole list of options. It makes sense to sort by frontmatter___date so let's add that to our query.

Go to back to our allMarkdownRemark , click on frontmatter , and we'll see that date has some options as well. We'll format it using formatString .

... export const query = graphql ` query { allMarkdownRemark ( sort: {order: DESC, fields: [frontmatter___date]} ) { edges { node { id frontmatter { title excerpt date(formatString: "MM.DD.YYYY") } } } } } `

Filtering

To show only certain posts depending on certain criteria, we can use filter . A common filter to display posts is by saying if a post is a draft or not. So let's go into our markdown files and add the field draft .

--- title: "My First Post" path: "/post-one" date: "2018-10-15" draft: false tags: ['gatsby', 'other'] --- This is my first post using Gatbsy.

We'll do the same in the other posts, but make the second post true and the third post false. Save and restart the server, and let's go back to the GraphiQL browser and check out frontmatter and we see draft has been added. Let's make a query to see what gets returned. We'll add filter onto its own line, and then say if the draft field from frontmatter is false, show the posts on the page.

{ allMarkdownRemark ( filter : { frontmatter : { draft : { eq : false } } } ) { edges { node { frontmatter } } } }

Run the query and we see only post one and three were returned, the two markdown files with draft: false . Let's add the filter into our our index file so the list only shows those two posts instead of all three.

... export const query = graphql` query { allMarkdownRemark ( filter : { frontmatter : { draft : { eq : false } } } sort : { order : DESC , fields : [ frontmatter___date ] } ) { ...

Creating Pages Programmatically

Now we want our list of posts to link to the actual posts. Let's try that by wrapping the title of our posts on the home page with Link . Import Link from gastby, and then add the frontmatter.path as the Link path.

... < Link to = { node . frontmatter . path } > < h3 > { node . frontmatter . title } </ h3 > </ Link > ...

And now that we added , we need to add path to our query as well.

... frontmatter { path title excerpt date ( formatString : "MM.DD.YYYY" ) } ...

And if we try it, we'll see it just brings us to the 404 page. That's because we haven't created the post pages yet. Gatsby will automatically create a page from any JS or JSX file inside the /src/pages directory, but if we want to create pages from each of our /content/post markdown files, a few things need to be done first. Create gatsby-node.js in the root, create the directory /src/templates and then create posts.jsx in the templates folder.

First let's just make a super basic component in post.jsx .

import React from 'react' import { graphql } from 'gatsby' const Post = ( props ) => { return ( < div > Post </ div > ) } export default Post

Next, in gatsby-node.js we're going to make use of createPages , one of Gatsby's APIs. We need to create the createPages export function, and then destructure actions, which is where createPages is located, and the function then returns a new promise since file creation is async by nature.

To create the page, it needs to be able to access the post template we just made. Create a variable and use path.resolve with the path to the template. Then call our graphql query to resolve the promise starting with allMarkdownRemark and including the file path .

Now let's pass the result into a function with a then, write a quick reject, and the result will be result.data.allMarkdownRemark.edges , an object that matches the query above. Since edges are the path to our files, we'll add a forEach on the edges to extract our file's path from node.frontmatter.

Let's destructure that and add it to the posts variable. Destructuring the node , we'll set the path as node.frontmatter.path , and then call the createPage action. The first parameter should be the path, the second parameter is the component we want to render, which is the post template, and the last object is the context which will be passed into our post template as a prop.

We want the post template to have the file path, so we'll name it pathSlug because path is reserved. As a side note, context is optional as it has defaults built in.

To summarize what's going on, we made a query that finds our files and gets the path from frontmatter. We cycle through them and call createPage which will use our post template to create a new page for each of our markdown files.

const path = require ( 'path' ) exports . createPages = ( ( { graphql , actions } ) => { const { createPage } = actions return new Promise ( ( resolve , reject ) => { const postTemplate = path . resolve ( 'src/templates/post.jsx' ) resolve ( graphql ( ` query { allMarkdownRemark { edges { node { frontmatter { path title } } } } } ` ) . then ( result => { if ( result . errors ) { return Promise . reject ( result . errors ) } const posts = result . data . allMarkdownRemark . edges ; posts . forEach ( ( { node } ) => { const path = node . frontmatter . path createPage ( { path , component : postTemplate , context : { pathSlug : path } } ) } ) } ) ) } ) } )

After restarting the server, let's go back to our post template and add a console.log to see if our data made it through. In the dev tools, look at the console and all of the correct data for our post should be there.

We want to render all the content onto the page, so let's head back over to the post template and write a graphql query. To get the path, write a slug variable with the $pathSlug that we added previously, and then make it a required String. Since we want only one markdown file, use markdownRemark instead of allMarkdownRemark.

Now we need to write a GraphQL query to search markdownRemark for the markdown files. Testing it out on the GraphiQL explorer, we can see what our options are.

So let's see if we can pull in the data properly. The data gets passed as a prop from the query, so we'll try <h1>{props.data.markdownRemark.frontmatter.title}</h1> and save it.

Now that we've confirmed it works properly, let's break up the props. Change the props to data and since we'll be using data.markdownRemark for all of our variables, we'll set const post = data.markdownRemark. Set the title as a variable const title = post.frontmatter.title and the same for date . To render the HTML, we're going to make use of React's dangerouslySetInnerHTML API.

To do so, we need to define html. If we look in GraphiQL we'll see that html isn't in frontmatter, but just in markdownRemark. So we'll define the html variable as post.html , and then pass in __html as an object with a value of html.

import { graphql } from 'gatsby' import Layout from '../layouts' const Post = ( { data } ) => { const post = data . markdownRemark const title = post . frontmatter . title const date = post . frontmatter . date const html = post . html return ( < Layout > < h1 > { title } </ h1 > < p > { date } </ p > < div dangerouslySetInnerHTML = { { __html : html } } /> </ Layout > ) } export const query = graphql ` query($pathSlug: String!) { markdownRemark(frontmatter: { path: {eq: $pathSlug} }) { html frontmatter { date title } } } ` export default Post

Now let's add tags to the site so we can browse posts by the tag. First, make the tags.jsx page, and the tag.jsx template. We'll make it a very simple component that has some text just to test that it works for now.

import React from 'react' const Tags = ( ) => { return ( < div > Tags Page Here </ div > ) } export default Tags

First let's think about what the tag actually is and how it's working within our project. At a basic level, it's not a page or a post or a template really. We're just creating all of that out of a single word or line of text inside our markdown files. They'll change when we add new posts with new tags, and if the same tag is used for mutliple posts, we don't want duplicates of the tag in a tag list.

Moving back to gatsby-node.js , we're going to want a variable for our template and page files, so we'll do the same path.resolve(/path/to/template) we did earlier, and add it under the existing postTemplate within the Promise.

Next, instead of creating a single entity, we'll create an object that will dynamically create a key for each tag which will then hold an array for each post that contains that specific tag. So we'll do posts.forEach to iterate over the array, and then destructure node and write an if statement to check if there is not a post with the tag as a key. We'll then set the \[tag] as an empty array and push the node. So now this object has each tag being represented by an array of nodes.

To create a list of all the tags, set tags equal to Object.keys and then add a createPage like we did earlier with our posts. We'll make the path be /tags, the component is tagPosts and to get a sorted list of tags, add tags.sort() to the context.

const path = require ( 'path' ) exports . createPages = ( ( { graphql , actions } ) => { const { createPage } = actions return new Promise ( ( resolve , reject ) => { const postTemplate = path . resolve ( 'src/templates/post.jsx' ) const tagPage = path . resolve ( 'src/pages/tags.jsx' ) ; const tagPosts = path . resolve ( 'src/templates/tag.jsx' ) ; resolve ( graphql ( ` query { allMarkdownRemark { edges { node { frontmatter { path title tags } } } } } ` ) . then ( result => { if ( result . errors ) { return Promise . reject ( result . errors ) } const posts = result . data . allMarkdownRemark . edges ; const postsByTag = { } ; posts . forEach ( ( { node } ) => { if ( node . frontmatter . tags ) { node . frontmatter . tags . forEach ( tag => { if ( ! postsByTag [ tag ] ) { postsByTag [ tag ] = [ ] ; } postsByTag [ tag ] . push ( node ) ; } ) ; } } ) ; const tags = Object . keys ( postsByTag ) ; createPage ( { path : '/tags' , component : tagPage , context : { tags : tags . sort ( ) , } , } ) ; posts . forEach ( ( { node } ) => { const path = node . frontmatter . path createPage ( { path , component : postTemplate , context : { pathSlug : path } } ) } ) } ) ) } ) } )

Now we want to actually pull in our tags on the tags page. Go to tags.jsx and let's add pageContext as props. To see what data is being passed, we'll add a console.log(pageContext) . pageContext is the data getting passed from gatbsy-node.js , which in this case, is the tags we added. Now checking the console we see the tags: Array with all of our tags.

import React from 'react' const Tags = ( { pageContext } ) => { console . log ( pageContext ) return ( < div > Tags Page Here </ div > ) } export default Tags

Now that the tags page is working we need to edit our tag template. This will be the page that loads when the individual tags are clicked and they will list the posts that contain that specific tag. First create the actual /tags/${tagName} pages in gatsby-node.js . Next add a tag.forEach to iterate each tag name. Then we need to use our list of nodes we made previously as [tagName] . Now just call another createPage with the path being /tag/${tagName}, the component is the tagPosts, and then the context the posts and tagName.

... tags . forEach ( tagName => { const posts = postsByTag [ tagName ] ; createPage ( { path : `/tags/ ${ tagName } ` , component : tagPosts , context : { posts , tagName , } , } ) ; } ) ; ...

Now let's go into our tag.jsx template. Let's first check we did this correctly by console logging the pageContext again. Go to a tag page and see the correct tag in the posts array in our console. Then, destructure pageContext into the posts and tagName . Next, add a title to show what the page is about with $ {tagName}. Now add a <ul> which will map over the posts to return an <li> . As always, we should add a key to any list, so we'll add an index and set the key to the index. Then add a <Link> to post.frontmatter.path with the post.frontmatter.title . Save it, and we'll see a list of tags that link to individual tags.

import React from 'react' import { Link } from 'gatsby' const Tag = ( { pageContext } ) => { const { posts , tagName } = pageContext return ( < div > < div > Posts about { ` ${ tagName } ` } </ div > < div > < ul > { posts . map ( ( post , index ) => { return ( < li key = { index } > < Link to = { post . frontmatter . path } > { post . frontmatter . title } </ Link > </ li > ) } ) } </ ul > </ div > </ div > ) } export default Tag

We'll now do something similar to our tag page. This time though, we'll only be destructuring tags from pageContext. Add a ul which will map over the tags, add a key again, and then add a <Link> to ${/tags/${tagName}} .

import React from 'react' import { Link } from 'gatsby' const Tags = ( { pageContext } ) => { console . log ( pageContext ) const { tags } = pageContext return ( < div > < ul > { tags . map ( ( tagName , index ) => { return ( < li key = { index } > < Link to = { `/tags/ ${ tagName } ` } > { tagName } </ Link > </ li > ) } ) } </ ul > </ div > ) } export default Tags

Since we'll be using this tag list in multiple places, let's use this opportunity to break out the code and make a separate component that will be a block of tags that will be displayed on each post. Let's make an src/component folder and make TagsBlock.jsx . Import Link from gatsby and then pass in list. We're going to map over list with a Link that goes to /tags/${tag} . And that's it.

import React from 'react' import { Link } from 'gatsby' const TagsBlock = ( { list } ) => { return ( < div > { list . map ( tag => < Link key = { tag } to = { `/tags/ ${ tag } ` } > { tag } </ Link > ) } </ div > ) } export default TagsBlock

Back on the post template, we'll first import TagsBlock and then stick it under the title. On the list prop, pass the tags from {post.frontmatter.tags} or an empty array in case there are no tags.

< TagsBlock list = { post . frontmatter . tags || [ ] } />

Let's see what happens if we don't add the || [] . In the last post markdown file, let's delete the entire tags field, and save. In the second to last post, let's just delete the tags but leave an empty array. If we load the second to last post, it's fine, there just aren't any tags. But if we go to the last post that doesn't even have the tags field, the page doesn't load. There are plenty of other ways to achieve this without needing a || [] at all, but that'll do for right now.

I wanted to point this out because this is something to watch out for when developing your Gatsby site. If a page loads but neither content nor errors are showing up, but when checking the console, an error does get listed, and it says something weird like "Cannot read property 'map' of null", go back and check all of your queries and data being passed. Sometimes just forgetting a single word will do it.

Now that we have a TagsBlock component, let's go back to our tags.jsx , swap it in, and pass {tags} as the list prop.

import React from 'react' import TagsBlock from '../components/TagsBlock' const Tags = ( { pageContext } ) => { console . log ( pageContext ) const { tags } = pageContext return ( < div > < TagsBlock list = { tags } /> </ div > ) } export default Tags

So much cleaner.

Simple Pagination

Now that the posts are up and running, we want to be able to navigate through them without having to go back to the home page. To do this, we'll add previous and next buttons. Go back to the gatsby-node.js , and inside the forEach, add an index so we know where we're located in the list as a whole.

For prev , we can start by saying if our index is zero, then we won't need previous because there isn't a post to move backwards to. Otherwise, we'll get the post[index - 1].node which is the post that comes before the current post. For next , it'll be the same thing but reversed. We'll say (posts.length - 1) , so if it's the last post, there is no next. Otherwise we'll get the post[index + 1].node, which is the post after the current post.

... posts . forEach ( ( { node } , index ) => { const path = node . frontmatter . path const prev = index === 0 ? null : posts [ index - 1 ] . node ; const next = index === posts . length - 1 ? null : posts [ index + 1 ] . node ; createPage ( { path , component : postTemplate , context : { pathSlug : path , prev , next , } } ) ; } ) ; ...

Now let's see if it worked. We'll go to our post.jsx and add the pageContext key, and then console.log(pageContext). Let's load our first post and look in the console. We see next: null and data for previous . This is obviously backwards because there shouldn't be data for previous on the first post. To fix this we just need to use sort like we did a little earlier. Go back to gatsby-node.js and add the sort keyword, which takes an object of order by ascending, and by the field frontmatter___date.

... query { allMarkdownRemark ( sort : { order : ASC , fields : [ frontmatter___date ] } ) { edges { node { frontmatter { path title date } } } } } ...

Reload the server and go back to our first post and check the console. Next has data and prev is null, and on the last post next is null and prev has data, so it works!

Now to add the Next and Previous links to the posts. Go back to our post.jsx and import Link from gatsby, destructure prev and next from our pageContext . We'll start with {next && , and add a component to {next.frontmatter.path} . The double ampersand checks the truthiness of the value and so if next is true, it will render this Link. And we'll just do the same thing again but replace next with prev, and wrap each one in a div so they're not stuck right next to each other.

import React from 'react' import { graphql , Link } from 'gatsby' import Layout from '../layouts' const Post = ( { data , pageContext } ) => { const { next , prev } = pageContext const post = data . markdownRemark const title = post . frontmatter . title const date = post . frontmatter . date const html = post . html return ( < Layout > < h1 > { title } </ h1 > < p > { date } </ p > < div dangerouslySetInnerHTML = { { __html : html } } /> < div > { next && < Link to = { next . frontmatter . path } > Next Post </ Link > } </ div > < div > { prev && < Link to = { prev . frontmatter . path } > Previous Post </ Link > } </ div > </ Layout > ) }

Using Images

The site works, but it's not much of a looker. We'll get into styling in the next section, but right now let's just bring some images in to make the site more alive. There are a few ways of doing this but in this tutorial we're going to be focusing on two ways in particular- the JavaScript import, and using Gatsby Plugins.

JavaScript Import

The first way to add an image to our Gatsby site is to import it like you would in any JavaScript file. Let's add a logo to the site. First make an static folder to hold the logo file, and then add logo into the folder.

Now, since this is a logo, we want it to show on all pages. Go to the Layout component and write the import statement, and just call it logo for simplicity. Add the img and pull in the logo variable we just imported as

import React from 'react' import { graphql , StaticQuery , Link } from 'gatsby' import logo from '../static/logo/gatsby.svg' ... render = { data => ( < div > < img src = { logo } alt = ' Gatsby Logo ' /> < Link to = { `/` } > ...

A really cool thig about Gatsby is all the settings that come built-in. Relating to images, Gatbsy's default webpack settings are focused on performance. When Gatbsy bundles any file that is less than 10KB, it will return a data uri which will result in fewer browser requests which increases the performance of the app. If it's over 10KB, it'll be bundled into the static folder. To see a quick example of this, import a large jpg file into Layout, and then console.log both the jpg and our previously imported icon.

... import logo from '../static/logo/gatsby.svg' import jpg from '../static/logo/gatsby.jpg' console . log ( jpg ) console . log ( logo ) ...

In our console, we can see that the jpg is in the static folder, and the svg has been turned into a data uri.

Images Through Gatsby Plugins

One thing our posts are lacking is an image. As previously mentioned, we have some gatsby plugins available to us to help make everything super smooth and performant. First, npm i gatsby-transformer-sharp gatsby-plugin-sharp gatsby-remark-images gatsby-image .

Head over to gatsby-config.js so we can make use of our new plugins. Add gatsby-transformer-sharp, resolve gatsby-transmforer-remark, and then resolve gatbsy-remark-images as a plugin of the transformer-remark. We have some options for remark-images, so let's set the max width , quality , and then add a link to the original image. Underneath all that we'll load gatsby-plugin-sharp.

plugins : [ { resolve : `gatsby-source-filesystem` , options : { name : `posts` , path : ` ${ __dirname } /content/posts` } , } , 'gatsby-transformer-sharp' , { resolve : `gatsby-transformer-remark` , options : { plugins : [ { resolve : 'gatsby-remark-images' , options : { maxWidth : 750 , quality : 90 , linkImagesToOriginal : true , } } ] } } , 'gatsby-plugin-sharp' ] }

Now let's add the images to our post folders, and then add the field cover , as in cover photo, to our frontmatter, with the path to our images.

--- path: "/post-two" cover: "./network.jpg" ...

Go to the post.jsx template file and connect all of it together through a query. First, import Img from gatsby-image , add cover, childImageSharp, fluid, and then some arguments.

... return ( < Layout > < Img fluid = { post . frontmatter . cover . childImageSharp . fluid } /> < h1 > { title } </ h1 > ... markdownRemark(frontmatter: { path : { eq : $pathSlug } } ) { html frontmatter { date title tags slug cover { childImageSharp { fluid ( maxWidth : 1920 , quality : 90 , duotone : { highlight : "#386eee" , shadow : "#2323be" , opacity : 40 } ) { ... GatsbyImageSharpFluid_withWebp } resize ( width : 1200 , quality : 90 ) { src } } } ...

Now we need to go to index page and do something similar.

... frontmatter { title path excerpt date ( formatString : "MM.DD.YYYY" ) cover { childImageSharp { fluid ( maxWidth : 1000 , quality : 90 , traceSVG : { color : "#2B2B2F" } ) { ... GatsbyImageSharpFluid_withWebp_tracedSVG } } } } ...

Gatsby is designed to build incredibly fast sites, so why not utilize every tool available? Sure just importing a regular old works, but using plugins makes everything more performant. First, gatsby-image does a whole list of things. Taken from the docs, it:

-Loads the optimal size of image for each device size and screen resolution -Holds the image position while loading so your page doesn’t jump around as images load -Uses the "blur-up" effect i.e. it loads a tiny version of the image to show while the full image is loading -Alternatively provides a "traced placeholder" SVG of the image -Lazy loads images, which reduces bandwidth and speeds the initial load time -Uses WebP images, if browser supports the format

Gatsby-transformer-sharp creates the ImageSharp node. Gatsby-remark-images does the processing in markdown so pictures can be used in production builds, and it does a few other things similar to gatsby-image like adding an elastic container, generates multiple sizes, and uses 'blur-up'. And finally, gatsby-plugin-sharp is a helper plugin used by the other image plugins that also uses pngquant to compress images.

If you're not already sold, I don't know what else to tell you. If you've ever had to deal with resizing images, holding images, importing, compressing, using placeholders, using lazy loaders, and considering other browsers, you understand how amazing it is to control all of that with a few lines in your query.

Styling

Let's make this site look like something because it's getting painful to keep staring at.

Emotion

We'll be using Emotion here, but Styled Components could be used as well because of how similar they are. In fact, they're so similar, we could actually replace all react-emotion with styled-components in this project, and all we'd need to do to get it to work is change the name of the global injection. There are of course, more nuanced differences between the two, so read the docs to decide which is best for you.

Let's npm i emotion react-emotion emotion-theming, gatsby-plugin-emotion , and then add gatsby-plugin-emotion to the plugins in gatsby-config.js .

ThemeProvider, injectGlobal, and passing props

We're going to be passing some theme props with each example so let's start by making a config folder outside of the src and make a theme.js file. Next, go to the Layout component and set it up so we can pass the theme config through. First, break apart the layout a little to simplify it. We'll use Emotion's ThemeProvider . This is a wrapper component that will provide a theme to every component down the line in the render tree through the context API. Import the theme, and then pass the children through. Let's also make use of injectGlobal, which is a way to have a global style across the whole project. We'll import { injectGlobal } from emotion and then just write the css.

import React , { Fragment } from 'react' import { ThemeProvider } from 'emotion-theming' import { injectGlobal } from 'react-emotion' import theme from '../../config/theme' injectGlobal ` *, *:before, *:after { box-sizing: inherit; } html, body { width: 100%; height: 100%; margin: 0; padding: 0; } ` const Layout = ( { children } ) => ( < ThemeProvider theme = { theme } > < Fragment > { children } </ Fragment > </ ThemeProvider > ) export default Layout

So now, whatever we put inside the ThemeProvider tag will have the global style, as well as access to the props from the theme.js file. In our other components or pages, we just need to import the Layout component and then wrap everything with <Layout></Layout> . Going further, if you find yourself using the same style block for multiple components, you can break the styling off completely and make a single file like this:

import styled from 'react-emotion' const Foo = styled . div ` padding: 1rem 2rem; color: ${ props => props . theme . colors . black } ; ` export default Foo

And then reuse that file by importing it in multiple different components, saving a lot of code. First let's take what we deleted from the Layout and turn it into a NavBar component. And we'll do a few very cool things with emotion to style this. First, let's differentiate the menu links from the Logo that's also a link back to the homepage. We'll make a variable and call it "StyledLink". But since we're already importing and using Gatsby's Link, how are we going to style it? We'll decorate the { Link } with the StyledLink variable.

import React , { Fragment } from 'react' import { Link } from 'gatsby' import styled from 'react-emotion' import Headroom from 'react-headroom' import logo from '../static/logo/header-logo.png' const StyledLink = styled ( Link ) ` display: flex; font-weight: 700; align-items: center; ` const Nav = styled . nav ` display: flex; justify-content: flex-end; font-weight:500; font-size:1.25rem; align-items: center; ` const NavBar = ( ) => ( < Fragment > < StyledLink to = " / " > < img src = { logo } alt = ' Gatsby Logo ' /> </ StyledLink > < Nav > < Link to = ' / ' > Home </ Link > < Link to = ' /about ' > About </ Link > </ Nav > </ Fragment > ) export default NavBar

Let's make this even better. Instead of having to write out every single color, shadow, padding, alignment, whatever, we can just pass theme props to the styled variables. Go to the currently empty theme.js file and fill it out a little bit.

const colors = { black : { base : '#333438' , light : '#4b4e57' , lighter : '#696d77' , blue : '#2e3246' , } } const transition = { easeInOutCubic : 'cubic-bezier(0.645, 0.045, 0.355, 1)' , easeOutBack : 'cubic-bezier(0.175, 0.885, 0.32, 1.275)' , duration : '0.4s' , } const theme = { colors , transition , } export default theme

And now back in the nav, we can pass the theme styles as props. We can use those same props anywhere in our project, as long as it's somewhere down the tree of our Layout component with the ThemeProvider.

const Nav = styled . nav ` ... align-items: center; a { color: ${ props => props . theme . colors . black . base } ; margin-left: 2rem; transition: all ${ props => props . theme . transitions } ; &:hover { color: ${ props => props . theme . colors . black . lighter } ; } } `

Other Options - Styled JSX, Sass

There are other options for styling, of course. Setting up Sass is a breeze when using gatsby-plugin-sass , there are other plugins related to postcss, and another interesting option is styled-jsx . Styled-JSX was developed by Zeit, the people that brough us Next.js. It's actually gotten very powerful as of the last few updates, and it seems very similar to emotion or styled components in functionality, such as passing props, server or client rendering, etc. Though, all the styling is done within <style> tags inside your component like:

export default ( ) => ( < div > < style jsx > {` h3 { color: black; } `} </ style > < h3 > Good morning </ h3 > </ div > )

Typography

Let's also add some fonts. We're going to use gatbsy typography plugin, and typefaces, npm packages for single fonts. The idea is that self-hosted typefaces are much faster than having to load a typeface from something like Google Fonts. It also works offline as well. We'll use Open Sans and Candal here, but there are over 800 fonts to choose from. We'll npm i typeface-open-sans typeface-candal gatsby-plugin-typography and then create a typography.js file in the config folder.

In typography.js add the base font size, line height, and header weight. For the header and body fonts, we'll use system fonts. System fonts improve user experience and performance because there's a fallback for every system- BlinkMacSystemFont is for iOS, Segoe UI is Windows, Roboto is Android. We'll also add in the Open Sans and Candela that we installed.

import Typography from 'typography' ; const typography = new Typography ( { title : 'GatsbyTutorial' , baseFontSize : '18px' , baseLineHeight : 1.45 , headerWeight : 700 , headerFontFamily : [ 'Candal' '-apple-system' , 'BlinkMacSystemFont' , 'Segoe UI' , 'Roboto' , 'Helvetica' , 'Arial' , 'sans-serif' , ] , bodyFontFamily : [ 'Open Sans' , '-apple-system' , 'BlinkMacSystemFont' , 'Segoe UI' , 'Roboto' , 'Helvetica' , 'Arial' , 'sans-serif' , ] , } ) ; export default typography ;

Also add the fonts to theme.js .

const theme = { colors , transistion , fontFamily : { body : `Open Sans, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'` , heading : `Candal, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol'` , } } export default theme

And then import them in the layout file:

import 'typeface-open-sans' import 'typeface-candal'

Then add the typography plugin to gatsby-config.js .

... { resolve : 'gatsby-plugin-typography' , options : { pathToConfigModule : 'config/typography.js' , } , } , ...

SEO, Adding Manifest, Sitemap, Offline Support

Now let's get all our Google Lightouse scores maxed out at 100. We need to add a manifest for Progressive Web App support, offline support, a sitemap for crawlers, React Helmet and an SEO component to give the site SEO. Let's npm i react-helmet gatsby-plugin-react-helmet gatsby-plugin-manifest, gatsby-plugin-sitemap, gatsby-plugin-offline .

Create a site.js file in the config folder, and this will hold all the configurations for the SEO component and the manifest.

module . exports = { pathPrefix : '/' , title : 'Gatsby Tutorial Starter' , titleAlt : 'Gatsby Tutorial Starter' , description : 'A Gatsby V2 Starter Template Built with a Step By Step Guide' , url : 'https://gatsby-tutorial-starter.netlify.com' , siteURL : 'https://gatsby-tutorial-starter.netlify.com/' , siteLanguage : 'en' , logo : 'src/static/logo/logo.png' , banner : 'src/static/logo/banner.png' , favicon : 'src/static/logo/favicon.png' , shortName : 'GatsbyTut' , author : 'Justin' , themeColor : '#3e7bf2' , backgroundColor : '#d3e0ff' , twitter : '@justinformentin' , } ;

Open gatsby-config.js and import the config file. We'll delete the old siteMetadata and replace it. We're going to use the ES6 spread operator to grab the whole list from the config file.

const config = require ( './config/site' ) ; module . exports = { siteMetadata : { ... config } , ...

At the bottom of the file, we'll load the sitemap plugin first, then the manifest plugin, and we'll load what we just imported from the site.js file. Then at the very end, add the offline plugin. It's important to have the manifest before the offline plugin so it can cache the manifest file. This plugin also takes icons and generates different sizes for different devices. The reason to use a manifest is so your site can behave similar to native apps on mobile devices.

... 'gatsby-plugin-sitemap' , { resolve : 'gatsby-plugin-manifest' , options : { name : config . title , short_name : config . shortName , description : config . description , start_url : config . pathPrefix , background_color : config . backgroundColor , theme_color : config . themeColor , display : 'standalone' , icon : config . favicon , } , } , 'gatsby-plugin-offline' ] }

SEO File

Now we'll make an SEO.jsx component that can be imported in other files, such as our templates. We'll be passing the props from those pages into SEO.jsx , which will hold the basic data from our site.js config as props and we'll later use aliases and fallbacks for the other queries not stated in the props.

We'll use propTypes because we want to be certain we're getting all the correct data, so npm i prop-types now. We can use defaultProps to ensure that the siteMetadata from our site.js file gets used in case some property isn't explicitly defined.

We'll make a StaticQuery that has all the site's metadata in it. Then take the data from the query and create an object that will check if the props were used. If they weren't, it will fall back to defaults.

import React , { Component } from 'react' import Helmet from 'react-helmet' import PropTypes from 'prop-types' import { StaticQuery , graphql } from 'gatsby' const SEO = ( { title , desc , banner , pathname , article } ) => ( < StaticQuery query = { query } render = { ( { site : { buildTime , siteMetadata : { defaultTitle , titleAlt , shortName , author , siteLanguage , logo , siteUrl , pathPrefix , defaultDescription , defaultBanner , twitter , } , } , } ) => { const seo = { title : title || defaultTitle , description : defaultDescription || desc , image : ` ${ siteUrl } ${ banner || defaultBanner } ` , url : ` ${ siteUrl } ${ pathname || '/' } ` , } ; } } / > ) ; export default SEO SEO . propTypes = { title : PropTypes . string , desc : PropTypes . string , banner : PropTypes . string , pathname : PropTypes . string , article : PropTypes . bool , } ; SEO . defaultProps = { title : null , desc : null , banner : null , pathname : null , article : false , } ; const query = graphql ` query SEO { site { buildTime(formatString: "YYYY-MM-DD") siteMetadata { defaultTitle: title titleAlt shortName author siteLanguage logo siteUrl: url pathPrefix defaultDescription: description defaultBanner: banner twitter } } } ` ;

Now we'll be adding the schema JSON-LD so we can get those sweet google rich snippets. It's basically taking unstructured data from your website or app and structuring that data in a way that search engines can easily digest. So we'll take our site config and our site data, and pass the strings into objects to be structured automatically. To read more about it, visitschema.org and Moz's guide. As a side note, JSON-LD is actually a spec that is used for a lot more than SEO, and you can learn more on json-ld.org and also try out the json-ld.org playground.

... const seo = { title : title || defaultTitle , description : defaultDescription || desc , image : ` ${ siteUrl } ${ banner || defaultBanner } ` , url : ` ${ siteUrl } ${ pathname || '/' } ` , } ; const realPrefix = pathPrefix === '/' ? '' : pathPrefix ; let schemaOrgJSONLD = [ { '@context' : 'http://schema.org' , '@type' : 'WebSite' , '@id' : siteUrl , url : siteUrl , name : defaultTitle , alternateName : titleAlt || '' , } , ] ; if ( article ) { schemaOrgJSONLD = [ { '@context' : 'http://schema.org' , '@type' : 'BlogPosting' , '@id' : seo . url , url : seo . url , name : title , alternateName : titleAlt || '' , headline : title , image : { '@type' : 'ImageObject' , url : seo . image , } , description : seo . description , datePublished : buildTime , dateModified : buildTime , author : { '@type' : 'Person' , name : author , } , publisher : { '@type' : 'Organization' , name : author , logo : { '@type' : 'ImageObject' , url : siteUrl + realPrefix + logo , } , } , isPartOf : siteUrl , mainEntityOfPage : { '@type' : 'WebSite' , '@id' : siteUrl , } , } , ] ; } } } / > ) ; ...

Now to add React Helmet , a package that allows management of the document head. Gatbsy's react helmet plugin provides support for server rendering data. Anything added to the Helmet component will be automatically generated as static HTML.

This is important because having pages only in JavaScript is generally not good for SEO. Crawlers like Googlebot have no problem with server-side rendered content, but when a site or app is client-side rendered, Googlebot will get a blank HTML page on intitial load. Then the JavaScript content is asynchronously downloaded. So Helmet is necessary to ensure all pages get rendered with a corresponding HTML page with the correct tags.

So we'll add data like the tite, language, description, and then add a block for 'OpenGraph', which is for facebook, and a block for twitter cards, and just pass in all the same data.

... '@id' : siteUrl , } , } , ] ; } return ( < > < Helmet title = { seo . title } > < html lang = { siteLanguage } /> < meta name = " description " content = { seo . description } /> < meta name = " image " content = { seo . image } /> < meta name = " apple-mobile-web-app-title " content = { shortName } /> < meta name = " application-name " content = { shortName } /> < script type = " application/ld+json " > {JSON.stringify(schemaOrgJSONLD)} </ script > { } < meta property = " og:url " content = { seo . url } /> < meta property = " og:type " content = { article ? 'article' : null } /> < meta property = " og:title " content = { seo . title } /> < meta property = " og:description " content = { seo . description } /> < meta property = " og:image " content = { seo . image } /> { } < meta name = " twitter:card " content = " summary_large_image " /> < meta name = " twitter:creator " content = { twitter } /> < meta name = " twitter:title " content = { seo . title } /> < meta name = " twitter:description " content = { seo . description } /> < meta name = " twitter:image " content = { seo . image } /> </ Helmet > </ > ) ; } } / > ) ; ...

Now we can import and add the SEO component to our layout. We can also add it to pages like our post.jsx , and pass in props to give the actual page value instead of the site defaults.

... return ( < Layout > < SEO title = { title } description = { post . frontmatter . description || post . excerpt || ' ' } image = { image } pathname = { post . frontmatter . path } article /> ...

And we can use <Helmet> in files like our blog.jsx page:

... return ( < Layout > < Helmet title = { 'Blog' } /> ...

Cleaning Up

This isn't specific to Gatsby, but it's always a good idea to make sure all your code is clean. We'll be using ESLint and Prettier. Let's npm i babel-eslint eslint prettier eslint-config-prettier eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-prettier eslint-plugin-react --save-dev .

eslint-config-prettier turns off rules that may conflict with prettier.

turns off rules that may conflict with prettier. eslint-plugin-import supports ES6+ import/export syntax.

supports ES6+ import/export syntax. eslint-plugin-prettier runs prettier as an ESLint rule.

runs prettier as an ESLint rule. eslint-plugin-jsx-a11y for accessibility rule checking.

for accessibility rule checking. eslint-plugin-react React specific rules.

In package.json add two scripts to run linting and formatting.

... "scripts" : { "develop" : "gatsby develop" , "build" : "gatsby build" , "serve" : "gatsby serve" , "lint" : "eslint src/**/*.{js,jsx}" , "format" : "prettier --write src/**/*.{js,jsx}" } , ...

Then create .eslintrc in the root of the project and add to it:

{ "parser" : "babel-eslint" , "env" : { "browser" : true , "node" : true , "es6" : true } , "rules" : { "strict" : 0 , "no-console" : "warn" , "quotes" : [ "warn" , "single" ] , "no-unused-vars" : [ 1 ] , "react/jsx-filename-extension" : [ 1 , { "extensions" : [ ".js" , ".jsx" ] } ] , "prettier/prettier" : "warn" } , "extends" : [ "eslint:recommended" , "plugin:react/recommended" , "plugin:jsx-a11y/recommended" ] , "plugins" : [ "prettier" , "jsx-a11y" ] }

In .pretierrc add a few rules. There are many rules that have a default, so they don't need to be specified.

Some defaults are:

"printWidth": 80 "semi": true "bracketSpacing": true "jsxBracketSameLine": false

We want those rules, so we just won't add them to the file.

{ "singleQuote" : true , "trailingComma" : "es5" , }

Format your project with npm run format and a list of files that were edited will be printed. ESLint will also be running, and unless you're a freak of nature, there will probably be errors in some files. Also notice Prettier added semicolons and commas, and maybe broke apart some lines that were over 80 characters long. Now is a good time to go through all of the files and fix whatever errors ESLint is mentioning.

Deploying

Now that we have a fully functional website, we can deploy it for the whole world to see. Since we just built a static site, we have many options. Netlify, Surge, Heroku and Github Pages are just a few examples of some places to host the site that are either free or have a free tier.

Conclusion

Gatsby is an amazing tool that makes it easy to build incredibly fast websites. Seriously, build and serve the project and run a Google Lighthouse audit. You should get 100 in every category.

But this is just an overview of Gatsby by building the most basic blog site; much more can be done.

The code for this guide can be found in the repository's master branch.

If you have any questions, please send me a message on Twitter.