Whats happening in that monolithic block of code? React media is using a Ternary operation to determine what to render based on a maxWidth of 848px . When the screen matches the width, only Header and children() components are rendered.

 {matches => matches ? ( ...stuff to render... ) : ( ...stuff to render... ) } 

If you noticed, we also used Flexbox to layout the positions of the children() and Sidebar components.

Run gatsby develop on the terminal and our static blog should look this way now:

3. Creating Blog posts

Now lets get into creating actual blog posts. Gatsby utilizes GraphQL to fetch data from one or many sources such as your local disk, Wordpress API, and so on.

Personally, I like the fact that I can create a static blog and fetch content from a WordPress API. My client has access to the Wordpress Editor where he creates posts, and I avoid dealing with all the hassles of developing a Wordpress site.

In this post, we will load the data from Markdown files we will create on our local disk. The gatsby-source-filesystem plugin we configured earlier expects our content to be in src/pages, so that’s exactly where we’ll put it!

A typical practice for blog posts is to name the folder something like MM-DD-YYYY-title. You can name it whatever you like or just place a markdown file inside the /pages folder.

Let’s create a folder src/pages/12–22–2017-first-post, and place an index.md inside. Write:

---path: "/hello-world"date: "2017-07-12T17:12:33.962Z"title: "My First Gatsby Post"---

Oooooh-weeee, my first blog post!

First post Ipsum is a major key to success. Congratulations, you played yourself. Surround yourself with angels. Celebrate success right, the only way, apple. The key is to drink coconut, fresh coconut, trust me. Egg whites, turkey sausage, wheat toast, water. Of course they don’t want us to eat our breakfast, so we are going to enjoy our breakfast. 

The block surrounded in dashes is referred to as frontmatter. The data we specify here, as well as other Markdown files, will be recognized by the gatsby-transformer-remark plugin.

The plugin will convert the frontmatter metadata part of your markdown file to frontmatter and the content part (Yippeeee, my first blog post!) to HTML.

When we begin generating blog pages directly from markdown files in section 4 (next section), path will be used to specify the URL path to render the file. For instance, the markdown file above will be rendered at localhost:8000/hello-world.

Before that, lets create a template that will render any markdown file into its own blog page. Create the file src/templates/blog-post.js (please create thesrc/templates folder).

import React from "react";import Helmet from "react-helmet";

export default function Template({ data }) { const post = data.markdownRemark; return ( 
{post.frontmatter.title}
 );}

We’ve set up the Template component to receive a data object which will come from the GraphQL query we are about to write.

Once again, the GraphQL query is needed to fetch data into the component. The result of the query is injected by Gatsby into the Template component as data and markdownRemark.

We will find that the markdownRemark property contains all the details of the Markdown file.

Lets now actually make the query. It should be placed below the Template component:

export const pageQuery = graphql` query BlogPostByPath($path: String!) { markdownRemark(frontmatter: { path: { eq: $path } }) { html frontmatter { date(formatString: "MMMM DD, YYYY") path title } } }`;

If you’re not familiar with GraphQL, I’ll try to break down what’s going on here. To learn more about GraphQL, consider this excellent resource.

GraphQL is just Facebook’s idea of a certain type of server. They’ve written a specification on the kind of requests that can be sent to that server and how the server should respond. GraphQL’s API is better than REST, because you describe the exact data the client-side needs so there’s no more under-fetching or over-fetching of data.

This means you have to create your own GraphQL server. Fortunately for us, GatsbyJS comes with its own GraphQL server out of the box.

In the code above, BlogPostByPath is the underlying query which will result in a blog post being returned. It will be returned as data for injection into the Template component.

We pass BlogPostByPath the $path argument to return a blog post related to the path we are currently viewing.

Furthermore, recall markdownRemark transformed our markdown files. It will be treated as a property whose contents will be available via data.markdownRemark.

We could access the HTML via data.markdownRemark.html. Also, the frontmatter content we created with a block of dahes can be accessed via data.markdownRemark.title etc.

The entire blog-template.js should look like this:

import React from "react";import Helmet from "react-helmet";

export default function Template({ data }) { const post = data.markdownRemark; return ( 
{post.frontmatter.title}
 );}

export const pageQuery = graphql` query BlogPostByPath($path: String!) { markdownRemark(frontmatter: { path: { eq: $path } }) { html frontmatter { date(formatString: "MMMM DD, YYYY") path title } } }`;

At this point:

• We have a bunch of plugins installed to perform some utilities as well as load files off of disk and transform Markdown to HTML.
• We have a single, lonely Markdown file that will be rendered as a blog post.
• We have a React template for rendering blog posts in a layout, as well as a wired up GraphQL to query for blog post data and inject the React template with the queried data.

Sweet!

4. Generating new pages from blog post data.

Gatsby provides a Node API, which provides functionality for creating dynamic pages from blog posts. This API is exposed in thegatsby-node.js file in the root directory of your project. This file could export several Node APIs but we are interested in the createPages API.

Utilize the following block of code snippet as provided in the official docs (Note that blogPostTemplate path was set to reflect ours):

const path = require('path');

exports.createPages = ({ boundActionCreators, graphql }) => { const { createPage } = boundActionCreators;

const blogPostTemplate = path.resolve(`src/templates/blog-post.js`);

return graphql(`{ allMarkdownRemark( sort: { order: DESC, fields: [frontmatter___date] } limit: 1000 ) { edges { node { excerpt(pruneLength: 250) html id frontmatter { date path title } } } } }`) .then(result => { if (result.errors) { return Promise.reject(result.errors); }

result.data.allMarkdownRemark.edges .forEach(({ node }) => { createPage({ path: node.frontmatter.path, component: blogPostTemplate, context: {} // additional data can be passed via context }); }); });}

Check if it works. I recommend closing your broswer window, stoppingthe gatsby develop server from the terminal using ctrl c. Now run gatsby develop again and open //localhost:8000/hello-world.

Create another file src/pages/24–12–2017-learning-grid/index.md

---path: "/another-one"date: "2017-07-12T17:12:33.962Z"title: "My Second Gatsby Post"---

In life there will be road blocks but we will over come it. Special cloth alert. Don’t ever play yourself. The key to more success is to get a massage once a week, very important, major key, cloth talk.

// some css grid code 

Again, close your broswer window, stop gatsby develop server. Run gatsby develop again and open //localhost:8000/another-one. This is shown:

Go on if you wish and create your own pages. ✌

5. Create a list of our site’s markdown files in the landing page.

The default landing page that comes with the scaffolded Gatsby site is located at src/pages/index.js. This is where we would define a template, and make a query to inject it with data for the list of .md files. Do this:

import React from "react";import Link from "gatsby-link";import Helmet from "react-helmet";

import '../styles/blog-listing.css';

export default function Index({ data }) { const { edges: posts } = data.allMarkdownRemark; return ( {posts .filter(post => post.node.frontmatter.title.length > 0) .map(({ node: post }) => { return ( 
 {post.frontmatter.title} 
{post.frontmatter.date}
{post.excerpt}
 ); })} );}

export const pageQuery = graphql` query IndexQuery { allMarkdownRemark(sort: { order: DESC, fields: [frontmatter___date] }) { edges { node { excerpt(pruneLength: 250) id frontmatter { title date(formatString: "MMMM DD, YYYY") path } } } } }`;

I trust you are badass at this point and already familiar with whats going on. Note that we wrote an import above that does not exist. Now create the file /styles/blog-listing.css:

div.blog-post-preview { border-bottom: 2px solid #e6e6e6; padding-top: 1rem; padding-bottom: 1rem; margin-bottom: 1rem;}

h1 > * { font-size: 1.2rem; text-decoration-line: none;}

h2 { font-size: 0.8rem !important; font-weight: 100 !important;}

Restart the server, visit the landing page, and you should see the listing at work:

Conclusion

We have come to the end of this tutorial. Thank you for reading thus far.

This post is just the tip of the iceberg considering the amount of things you could do with Gatsby. Feel free to explore how you could implement:

• Search functionality
• The use of tags to categorize blog posts
• Deploying your Gatsby site

You can grab the final source code here. Feel free to support me (devapparel.co) and look good while at it. Also, Comment or Share this post. Thanks for reading!

P.S I am working on a React book with Ohans Emmanuel that would have you master React by building 30 small projects in 30 days. If you want to stay updated on this, join the mailing list. Thanks!