Lesson 2: Hello world

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The content of this course was written in May 2020, so parts will be outdated. There’s no immediate plan to do a full update, but this course is now open source, so if you see an issue, please raise an issue.

Head over to the project and follow the contribution guide if you would like to help.

Now we have a better idea of what Eleventy is and have the tools we need to get started, let’s make something that we can see in the browser.

Remember dotfiles from the last lesson? Well now we’re going to add the most important dotfile of this entire project: .eleventy.js.

Create a new file in your eleventy-from-scratch folder called .eleventy.js and add the following to it:

module.exports = config => {
  return {
    dir: {
      input: 'src',
      output: 'dist'
    }
  };
};

This is our Eleventy Config file (opens new window). It's the beating heart of your Eleventy site. It delegates and instructs everything that makes up the final output.

What we've just added is the core, most basic config. We've exported a function (opens new window) which returns some settings. These settings tell Eleventy to look in the src folder for all of our content, templates and other source code, and tell it to use dist as the output folder.

Remember: the output will be folders and HTML pages (at the moment).

Adding some dependencies

We’ve chatted a lot about Eleventy so far, but still haven’t even installed it!

First, though, we need to get ourselves a package.json file. This contains metadata about the project and lets npm identify the project and handle its dependencies.

Because you already have Node.js installed, setting up your package.json file is really straightforward.

Make sure you're in your eleventy-from-scratch folder and run the following in your terminal:

npm init -y

You should see an output that looks like this:

{
  "name": "eleventy-from-scratch",
  "version": "1.0.0",
  "description": "",
  "main": ".eleventy.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}

What's happened here is that npm has generated a package.json file for us, and by using the -y flag, we told it to answer yes to all of the questions it would normally ask.

Now that’s sorted, we can install Eleventy. In the terminal, run the following command:

npm install @11ty/eleventy

We’ve installed a local version of Eleventy in our project. Let’s make it do something!

TIP

The eagle-eyed amongst you might have noticed that we didn’t install Eleventy globally. This is indeed what the quick start suggests on the Eleventy site (opens new window), but running packages locally, via npx is something I prefer to do, as a symptom of other, more complex projects in the past.

When you work in a team, running packages that are local to the project means that everyone is running off the same setup. This is especially important if you are using webpack (opens new window).

In the context of this course, it doesn’t really matter which way you choose to do it. Just bear in mind that the commands throughout the rest of this course will be related to using a local version of Eleventy.

Hello, world

In your eleventy-from-scratch/src folder, add a new file called index.md and add the following to it:

Hello, world

Yes, that’s pretty uneventful, but let’s now put Eleventy to work. Make sure you've saved your changes in your text editor. Then, in your terminal, in the eleventy-from-scratch folder, run the following command:

npx eleventy --serve

If you go to http://localhost:8080 (opens new window) in your browser, it should look like this:

Pretty cool, right?

TIP

By running npx we use the local Eleventy dependency. You can also use npx to run other packages, like Eleventy, locally (opens new window).

The --serve flag in our terminal command instructs Eleventy to serve the dist folder with a local web server and also watch for any file changes. This means that if you change the content of index.md and refresh your browser: you should see the new content.

Setting up our scripts

Running npx eleventy --serve in the terminal is easy enough, but it would be even easier to just run npm start instead. To do this, we use npm scripts (opens new window).

Open up eleventy-from-scratch/package.json and find the "scripts" element. Find the line that says "test": "echo \"Error: no test specified\" && exit 1" and replace it with the following:

"start": "npx eleventy --serve"

Your package.json file should now look like this:

{
  "name": "eleventy-from-scratch",
  "version": "1.0.0",
  "description": "",
  "main": ".eleventy.js",
  "scripts": {
    "start": "npx eleventy --serve"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@11ty/eleventy": "^0.11.0"
  }
}

Open your terminal again. Press ctrl and c at the same time to stop it, then run npm start. It should fire up that same “Hello, world” page at http://localhost:8080 (opens new window).

Wrapping up

We’ve achieved a lot in this lesson. We’ve installed Eleventy and got it up and running in an npm script. We’ve also added our first piece of content to the site which will become our home page.

Next up: we’re going to start digging into HTML and Nunjucks, which will suddenly start to make things really interesting.