
## Overview

A post on the new features introduced in v1.0. New features:

<TOCInline toc={props.toc} exclude="Overview" toHeading={2} />

First load JS decreased from 43kB to 39kB despite all the new features added! [^1]

[^1]: With the new changes in Nextjs 12, first load JS increase to 45kB.

See [upgrade guide](#upgrade-guide) below if you are migrating from v0 version of the template.

## Theme colors

You can easily modify the theme color by changing the primary attribute in the tailwind config file:

```js:tailwind.config.js
theme: {
    colors: {
      primary: colors.teal,
      gray: colors.neutral,
      ...
    }
  ...
}
```

The primary color attribute should be assigned an object with keys from 50, 100, 200 ... 900 and the corresponding color code values.

Tailwind includes great default color palettes that can be used for theming your own website. Check out [customizing colors documentation page](https://tailwindcss.com/docs/customizing-colors) for the full range of options.

Migrating from v1? You can revert to the previous theme by setting `primary` to `colors.sky` (Tailwind 2.2.2 and above, otherwise `colors.lightBlue`) and changing gray to `colors.gray`.

From v1.1.2+, you can also customize the style of your code blocks easily by modifying the `css/prism.css` stylesheet. Token classnames are compatible with prismjs
so you can copy and adapt token styles from a prismjs stylesheet e.g. [prism themes](https://github.com/PrismJS/prism-themes).

## Xdm MDX compiler

We switched the MDX bundler from [next-mdx-remote](https://github.com/hashicorp/next-mdx-remote) to [mdx-bundler](https://github.com/kentcdodds/mdx-bundler).
This uses [xdm](https://github.com/wooorm/xdm) under the hood, the latest micromark 3 and remark, rehype libraries.

**Warning:** If you were using custom remark or rehype libraries, please upgrade to micromark 3 compatible ones. If you are upgrading, please delete `node_modules` and `package-lock.json` to avoid having past dependencies related issues.

[xdm](https://github.com/wooorm/xdm) contains multiple improvements over [@mdx-js/mdx](https://github.com/mdx-js/mdx), the compiler used internally by next-mdx-remote, but there might be some breaking behaviour changes.
Please check your markdown output to verify.

Some new possibilities include loading components directly in the mdx file using the import syntax and including js code which could be compiled and bundled at the build step.

For example, the following jsx snippet can be used directly in an MDX file to render the page title component:

```jsx
// Or import PageTitle from './components/PageTitle.js' if you are using js
import PageTitle from "./components/PageTitle.tsx";
<PageTitle> Using JSX components in MDX </PageTitle>;
```

The default configuration resolves all components relative to the `components` directory.

**Note**:
Components which require external image loaders also require additional esbuild configuration.
Components which are dependent on global application state on lifecycle like the Nextjs `Link` component would also not work with this setup as each mdx file is built independently.
For such cases, it is better to use component substitution.

## Table of contents component

Inspired by [Docusaurus](https://docusaurus.io/docs/next/markdown-features/inline-toc) and Gatsby's [gatsby-remark-table-of-contents](https://www.gatsbyjs.com/plugins/gatsby-remark-table-of-contents/),
the `toc` variable containing all the top level headings of the document is passed to the MDX file and can be styled accordingly.
To make generating a table of contents (TOC) simple, you can use the existing `TOCInline` component.

For example, the TOC in this post was generated with the following code:

```jsx
<TOCInline toc={props.toc} exclude="Overview" toHeading={2} />
```

You can customise the headings that are displayed by configuring the `fromHeading` and `toHeading` props, or exclude particular headings
by passing a string or a string array to the `exclude` prop. By default, all headings that are of depth 3 or smaller are indented. This can be configured by changing the `indentDepth` property.
A `asDisclosure` prop can be used to render the TOC within an expandable disclosure element.

Here's the full TOC rendered in a disclosure element.

```jsx
<TOCInline toc={props.toc} asDisclosure />
```

<TOCInline toc={props.toc} asDisclosure />

## Layouts

You can map mdx blog content to layout components by configuring the frontmatter field. For example, this post is written with the new `PostSimple` layout!

### Adding new templates

layout templates are stored in the `./layouts` folder. You can add your React components that you want to map to markdown content in this folder.
The component file name must match that specified in the markdown frontmatter `layout` field.

The only required field is `children` which contains the rendered MDX content, though you would probably want to pass in the frontMatter contents and render it in the template.

You can configure the template to take in other fields - see `PostLayout` component for an example.

Here's an example layout which you can further customise:

```jsx
export default function ExampleLayout({ frontMatter, children }) {
  const { date, title } = frontMatter;

  return (
    <SectionContainer>
      <div>{date}</div>
      <h1>{title}</h1>
      <div>{children}</div>
    </SectionContainer>
  );
}
```

### Configuring a blog post frontmatter

Use the `layout` frontmatter field to specify the template you want to map the markdown post to. Here's how the frontmatter of this post looks like:

```
---
title: 'New features in v1'
date: '2021-05-26   '
tags: ['next-js', 'tailwind', 'guide']
draft: false
summary: 'Introducing the new layout features - you can map mdx blog content to layout components by configuring the frontmatter field'
layout: PostSimple
---
```

You can configure the default layout in the respective page section by modifying the `DEFAULT_LAYOUT` variable.
The `DEFAULT_LAYOUT` for blog posts page is set to `PostLayout`.

### Extend

`layout` is mapped to wrapper which wraps the entire MDX content.

```jsx
export const MDXComponents = {
  Image,
  a: CustomLink,
  pre: Pre,
  wrapper: ({ components, layout, ...rest }) => {
    const Layout = require(`../layouts/${layout}`).default;
    return <Layout {...rest} />;
  },
};

export const MDXLayoutRenderer = ({ layout, mdxSource, ...rest }) => {
  const MDXLayout = useMemo(() => getMDXComponent(mdxSource), [mdxSource]);

  return <MDXLayout layout={layout} components={MDXComponents} {...rest} />;
};
```

Use the `MDXLayoutRenderer` component on a page where you want to accept a layout name to map to the desired layout.
You need to pass the layout name from the layout folder (it has to be an exact match).

## Analytics

The template now supports [plausible](https://plausible.io/), [simple analytics](https://simpleanalytics.com/) and google analytics.
Configure `siteMetadata.js` with the settings that correspond with the desired analytics provider.

```js
analytics: {
    // supports plausible, simpleAnalytics or googleAnalytics
    plausibleDataDomain: '', // e.g. tailwind-nextjs-starter-blog.vercel.app
    simpleAnalytics: false, // true or false
    googleAnalyticsId: '', // e.g. UA-000000-2 or G-XXXXXXX
  },
```

Custom events are also supported. You can import the `logEvent` function from `@components/analytics/[ANALYTICS-PROVIDER]` file and call it when
triggering certain events of interest. _Note_: Additional configuration might be required depending on the analytics provider, please check their official
documentation for more information.

## Blog comments system

We have also added support for [giscus](https://github.com/laymonage/giscus), [utterances](https://github.com/utterance/utterances) or disqus.
To enable, simply configure `siteMetadata.js` comments property with the desired provider and settings as specified in the config file.

```js
comment: {
    // Select a provider and use the environment variables associated to it
    // https://vercel.com/docs/environment-variables
    provider: 'giscus', // supported providers: giscus, utterances, disqus
    giscusConfig: {
      // Visit the link below, and follow the steps in the 'configuration' section
      // https://giscus.app/
      repo: process.env.NEXT_PUBLIC_GISCUS_REPO,
      repositoryId: process.env.NEXT_PUBLIC_GISCUS_REPOSITORY_ID,
      category: process.env.NEXT_PUBLIC_GISCUS_CATEGORY,
      categoryId: process.env.NEXT_PUBLIC_GISCUS_CATEGORY_ID,
      mapping: 'pathname', // supported options: pathname, url, title
      reactions: '1', // Emoji reactions: 1 = enable / 0 = disable
      // Send discussion metadata periodically to the parent window: 1 = enable / 0 = disable
      metadata: '0',
      // theme example: light, dark, dark_dimmed, dark_high_contrast
      // transparent_dark, preferred_color_scheme, custom
      theme: 'light',
      // theme when dark mode
      darkTheme: 'transparent_dark',
      // If the theme option above is set to 'custom`
      // please provide a link below to your custom theme css file.
      // example: https://giscus.app/themes/custom_example.css
      themeURL: '',
    },
    utterancesConfig: {
      // Visit the link below, and follow the steps in the 'configuration' section
      // https://utteranc.es/
      repo: process.env.NEXT_PUBLIC_UTTERANCES_REPO,
      issueTerm: '', // supported options: pathname, url, title
      label: '', // label (optional): Comment 💬
      // theme example: github-light, github-dark, preferred-color-scheme
      // github-dark-orange, icy-dark, dark-blue, photon-dark, boxy-light
      theme: '',
      // theme when dark mode
      darkTheme: '',
    },
    disqus: {
      // https://help.disqus.com/en/articles/1717111-what-s-a-shortname
      shortname: process.env.NEXT_PUBLIC_DISQUS_SHORTNAME,
    },
  },
```

## Multiple authors

Information on authors is now split from `siteMetadata.js` and stored in its own `data/authors` folder as a markdown file. Minimally, you will need to have a `default.md` file with authorship information. You can create additional files as required and the file name will be used as the reference to the author.

Here's how an author markdown file might look like:

```md:default.md
---
name: Tails Azimuth
avatar: /static/images/avatar.png
occupation: Professor of Atmospheric Science
company: Stanford University
email: address@yoursite.com
twitter: https://twitter.com/Twitter
linkedin: https://www.linkedin.com
github: https://github.com
---

A long description of yourself...
```

You can use this information in multiple places across the template. For example in the about section of the page, we grab the default author information with this line of code:

```js
const authorDetails = await getFileBySlug("authors", ["default"]);
```

This is rendered in the `AuthorLayout` template.

### Multiple authors in blog post

The frontmatter of a blog post accepts an optional `authors` array field. If no field is specified, it is assumed that the default author is used. Simply pass in an array of authors to render multiple authors associated with a post.

For example, the following frontmatter will display the authors given by `data/authors/default.md` and `data/authors/sparrowhawk.md`

```yaml
title: "My first post"
date: "2021-01-12"
draft: false
summary: "My first post"
authors: ["default", "sparrowhawk"]
```

A demo of a multiple authors post is shown in [Introducing Tailwind Nextjs Starter Blog post](/blog/introducing-tailwind-nextjs-starter-blog).

## Copy button for code blocks

Hover over a code block and you will notice a GitHub-inspired copy button! You can modify `./components/Pre.js` to further customise it.
The component is passed to `MDXComponents` and modifies all `<pre>` blocks.

## Line highlighting and line numbers

Line highlighting and line numbers are now supported out of the box thanks to the new [rehype-prism-plus plugin](https://github.com/timlrx/rehype-prism-plus)

The following javascript code block:

````
```js {1, 3-4} showLineNumbers
var num1, num2, sum
num1 = prompt('Enter first number')
num2 = prompt('Enter second number')
sum = parseInt(num1) + parseInt(num2) // "+" means "add"
alert('Sum = ' + sum) // "+" means combine into a string
```
````

will appear as:

```js {1,3-4} showLineNumbers
var num1, num2, sum;
num1 = prompt("Enter first number");
num2 = prompt("Enter second number");
sum = parseInt(num1) + parseInt(num2); // "+" means "add"
alert("Sum = " + sum); // "+" means combine into a string
```

To modify the styles, change the following class selectors in the `prism.css` file:

```css
.code-highlight {
  @apply float-left min-w-full;
}

.code-line {
  @apply -mx-4 block border-l-4 border-opacity-0 pl-4 pr-4;
}

.code-line.inserted {
  @apply bg-green-500 bg-opacity-20;
}

.code-line.deleted {
  @apply bg-red-500 bg-opacity-20;
}

.highlight-line {
  @apply -mx-4 border-l-4 border-primary-500 bg-gray-700 bg-opacity-50;
}

.line-number::before {
  @apply -ml-2 mr-4 inline-block w-4 text-right text-gray-400;
  content: attr(line);
}
```

## Newletter component (v1.1.3)

Introduced in v1.1.3, the newsletter component gives you an easy way to build an audience. It integrates with the following providers:

- [Mailchimp](https://mailchimp.com/)
- [Buttondown](https://buttondown.email/)
- [Convertkit](https://convertkit.com/)

To use it, specify the provider which you are using in the config file and add the necessary environment variables to the `.env` file.
For more information on the required variables, check out `.env.sample.`

Two components are exported, a default `NewsletterForm` and a `BlogNewsletterForm` component, which is also passed in as an MDX component
and can be used in a blog post:

```jsx
<BlogNewsletterForm title="Like what you are reading?" />
```

<BlogNewsletterForm title="Like what you are reading?" />

The component relies on nextjs's [API routes](https://nextjs.org/docs/api-routes/introduction) which requires a server-side instance of nextjs to be setup
and is not compatible with a 100% static site export. Users should either self-host or use a compatible platform like Vercel or Netlify which supports this functionality.

A static site compatible alternative is to substitute the route in the newsletter component with a form API endpoint provider.

## Bibliography and Citations (v1.2.1)

`rehype-citation` plugin is added to the xdm processing pipeline in v1.2.1. This allows you to easily format citations and insert bibliography from an existing bibtex or CSL-json file.

For example, the following markdown code sample:

```md
Standard citation [@Nash1950]
In-text citations e.g. @Nash1951
Multiple citations [see @Nash1950; @Nash1951, page 50]

**References:**

[^ref]
```

is rendered to the following:

Standard citation [@Nash1950]  
In-text citations e.g. @Nash1951  
Multiple citations [see @Nash1950; @Nash1951, page 50]

**References:**

[^ref]

A bibliography will be inserted at the end of the document, but this can be overwritten by specifying a `[^Ref]` tag at the intended location.
The plugin uses APA citation formation, but also supports the following CSLs, 'apa', 'vancouver', 'harvard1', 'chicago', 'mla', or a path to a user-specified CSL file.

See [rehype-citation readme](https://github.com/timlrx/rehype-citation) for more information on the configuration options.

## Self-hosted font (v1.5.0)

Google font has been replaced with self-hosted font from [Fontsource](https://fontsource.org/). This gives the following [advantages](https://fontsource.org/docs/introduction):

> Self-hosting brings significant performance gains as loading fonts from hosted services, such as Google Fonts, lead to an extra (render blocking) network request. To provide perspective, for simple websites it has been seen to double visual load times.
>
> Fonts remain version locked. Google often pushes updates to their fonts without notice, which may interfere with your live production projects. Manage your fonts like any other NPM dependency.
>
> Commit to privacy. Google does track the usage of their fonts and for those who are extremely privacy concerned, self-hosting is an alternative.

This leads to a smaller font bundle and a 0.1s faster load time ([webpagetest comparison](https://www.webpagetest.org/video/compare.php?tests=220201_AiDcFH_f68a69b758454dd52d8e67493fdef7da,220201_BiDcMC_bf2d53f14483814ba61e794311dfa771)).

To change the default Inter font:

1. Install the preferred [font](https://fontsource.org/fonts) - `npm install -save @fontsource/<font-name>`
2. Update the import at `pages/_app.js`- `import '@fontsource/<font-name>.css'`
3. Update the `fontfamily` property in the tailwind css config file

## Upgrade guide

There are significant portions of the code that has been changed from v0 to v1 including support for layouts and a new mdx engine.

There's also no real reason to change if the previous one serves your needs and it might be easier to copy
the component changes you are interested in to your existing blog rather than migrating everything over.

Nonetheless, if you want to do so and have not changed much of the template, you could clone the new version and copy over the blog post over to the new template.

Another alternative would be to pull the latest template version with the following code:

```bash
git remote add template git@github.com:timlrx/tailwind-nextjs-starter-blog.git
git pull template v1 --allow-unrelated-histories
rm -rf node_modules
```

You can see an example of such a migration in this [commit](https://github.com/timlrx/timlrx.com/commit/bba1c185384fd6d5cdaac15abf802fdcff027286) for my personal blog.

v1 also uses `feed.xml` rather than `index.xml`, to avoid some build issues with Vercel. If you are migrating you should add a redirect to `next.config.js` like so:

```js
async redirects() {
  return [
    {
      source: '/:path/index.xml',
      destination: '/:path/feed.xml',
      permanent: true,
    }
  ]
}
```



# The Time Machine by H. G. Wells

_Title_: The Time Machine

_Author_: H. G. Wells

_Subject_: Science Fiction

_Language_: English

_Source_: [Project Gutenberg](https://www.gutenberg.org/ebooks/35)

## Introduction

The Time Traveller (for so it will be convenient to speak of him) was
expounding a recondite matter to us. His pale grey eyes shone and
twinkled, and his usually pale face was flushed and animated. The fire
burnt brightly, and the soft radiance of the incandescent lights in the
lilies of silver caught the bubbles that flashed and passed in our
glasses. Our chairs, being his patents, embraced and caressed us rather
than submitted to be sat upon, and there was that luxurious
after-dinner atmosphere, when thought runs gracefully free of the
trammels of precision. And he put it to us in this way—marking the
points with a lean forefinger—as we sat and lazily admired his
earnestness over this new paradox (as we thought it) and his fecundity.

“You must follow me carefully. I shall have to controvert one or two
ideas that are almost universally accepted. The geometry, for instance,
they taught you at school is founded on a misconception.”

“Is not that rather a large thing to expect us to begin upon?” said
Filby, an argumentative person with red hair.

“I do not mean to ask you to accept anything without reasonable ground
for it. You will soon admit as much as I need from you. You know of
course that a mathematical line, a line of thickness _nil_, has no real
existence. They taught you that? Neither has a mathematical plane.
These things are mere abstractions.”

“That is all right,” said the Psychologist.

“Nor, having only length, breadth, and thickness, can a cube have a
real existence.”

“There I object,” said Filby. “Of course a solid body may exist. All
real things—”

“So most people think. But wait a moment. Can an _instantaneous_ cube
exist?”

“Don’t follow you,” said Filby.

“Can a cube that does not last for any time at all, have a real
existence?”

Filby became pensive. “Clearly,” the Time Traveller proceeded, “any
real body must have extension in _four_ directions: it must have
Length, Breadth, Thickness, and—Duration. But through a natural
infirmity of the flesh, which I will explain to you in a moment, we
incline to overlook this fact. There are really four dimensions, three
which we call the three planes of Space, and a fourth, Time. There is,
however, a tendency to draw an unreal distinction between the former
three dimensions and the latter, because it happens that our
consciousness moves intermittently in one direction along the latter
from the beginning to the end of our lives.”

“That,” said a very young man, making spasmodic efforts to relight his
cigar over the lamp; “that . . . very clear indeed.”

“Now, it is very remarkable that this is so extensively overlooked,”
continued the Time Traveller, with a slight accession of cheerfulness.
“Really this is what is meant by the Fourth Dimension, though some
people who talk about the Fourth Dimension do not know they mean it. It
is only another way of looking at Time. _There is no difference between
Time and any of the three dimensions of Space except that our
consciousness moves along it_. But some foolish people have got hold of
the wrong side of that idea. You have all heard what they have to say
about this Fourth Dimension?”

“_I_ have not,” said the Provincial Mayor.

“It is simply this. That Space, as our mathematicians have it, is
spoken of as having three dimensions, which one may call Length,
Breadth, and Thickness, and is always definable by reference to three
planes, each at right angles to the others. But some philosophical
people have been asking why _three_ dimensions particularly—why not
another direction at right angles to the other three?—and have even
tried to construct a Four-Dimensional geometry. Professor Simon Newcomb
was expounding this to the New York Mathematical Society only a month
or so ago. You know how on a flat surface, which has only two
dimensions, we can represent a figure of a three-dimensional solid, and
similarly they think that by models of three dimensions they could
represent one of four—if they could master the perspective of the
thing. See?”

“I think so,” murmured the Provincial Mayor; and, knitting his brows,
he lapsed into an introspective state, his lips moving as one who
repeats mystic words. “Yes, I think I see it now,” he said after some
time, brightening in a quite transitory manner.

“Well, I do not mind telling you I have been at work upon this geometry
of Four Dimensions for some time. Some of my results are curious. For
instance, here is a portrait of a man at eight years old, another at
fifteen, another at seventeen, another at twenty-three, and so on. All
these are evidently sections, as it were, Three-Dimensional
representations of his Four-Dimensioned being, which is a fixed and
unalterable thing.

“Scientific people,” proceeded the Time Traveller, after the pause
required for the proper assimilation of this, “know very well that Time
is only a kind of Space. Here is a popular scientific diagram, a
weather record. This line I trace with my finger shows the movement of
the barometer. Yesterday it was so high, yesterday night it fell, then
this morning it rose again, and so gently upward to here. Surely the
mercury did not trace this line in any of the dimensions of Space
generally recognised? But certainly it traced such a line, and that
line, therefore, we must conclude, was along the Time-Dimension.”

“But,” said the Medical Man, staring hard at a coal in the fire, “if
Time is really only a fourth dimension of Space, why is it, and why has
it always been, regarded as something different? And why cannot we move
in Time as we move about in the other dimensions of Space?”

The Time Traveller smiled. “Are you so sure we can move freely in
Space? Right and left we can go, backward and forward freely enough,
and men always have done so. I admit we move freely in two dimensions.
But how about up and down? Gravitation limits us there.”

“Not exactly,” said the Medical Man. “There are balloons.”

“But before the balloons, save for spasmodic jumping and the
inequalities of the surface, man had no freedom of vertical movement.”

“Still they could move a little up and down,” said the Medical Man.

“Easier, far easier down than up.”

“And you cannot move at all in Time, you cannot get away from the
present moment.”

“My dear sir, that is just where you are wrong. That is just where the
whole world has gone wrong. We are always getting away from the present
moment. Our mental existences, which are immaterial and have no
dimensions, are passing along the Time-Dimension with a uniform
velocity from the cradle to the grave. Just as we should travel _down_
if we began our existence fifty miles above the earth’s surface.”

“But the great difficulty is this,” interrupted the Psychologist. ’You
_can_ move about in all directions of Space, but you cannot move about
in Time.”

“That is the germ of my great discovery. But you are wrong to say that
we cannot move about in Time. For instance, if I am recalling an
incident very vividly I go back to the instant of its occurrence: I
become absent-minded, as you say. I jump back for a moment. Of course
we have no means of staying back for any length of Time, any more than
a savage or an animal has of staying six feet above the ground. But a
civilised man is better off than the savage in this respect. He can go
up against gravitation in a balloon, and why should he not hope that
ultimately he may be able to stop or accelerate his drift along the
Time-Dimension, or even turn about and travel the other way?”

“Oh, _this_,” began Filby, “is all—”

“Why not?” said the Time Traveller.

“It’s against reason,” said Filby.

“What reason?” said the Time Traveller.

“You can show black is white by argument,” said Filby, “but you will
never convince me.”

“Possibly not,” said the Time Traveller. “But now you begin to see the
object of my investigations into the geometry of Four Dimensions. Long
ago I had a vague inkling of a machine—”

“To travel through Time!” exclaimed the Very Young Man.

“That shall travel indifferently in any direction of Space and Time, as
the driver determines.”

Filby contented himself with laughter.

“But I have experimental verification,” said the Time Traveller.

“It would be remarkably convenient for the historian,” the Psychologist
suggested. “One might travel back and verify the accepted account of
the Battle of Hastings, for instance!”

“Don’t you think you would attract attention?” said the Medical Man.
“Our ancestors had no great tolerance for anachronisms.”

“One might get one’s Greek from the very lips of Homer and Plato,” the
Very Young Man thought.

“In which case they would certainly plough you for the Little-go. The
German scholars have improved Greek so much.”

“Then there is the future,” said the Very Young Man. “Just think! One
might invest all one’s money, leave it to accumulate at interest, and
hurry on ahead!”

“To discover a society,” said I, “erected on a strictly communistic
basis.”

“Of all the wild extravagant theories!” began the Psychologist.

“Yes, so it seemed to me, and so I never talked of it until—”

“Experimental verification!” cried I. “You are going to verify _that_?”

“The experiment!” cried Filby, who was getting brain-weary.

“Let’s see your experiment anyhow,” said the Psychologist, “though it’s
all humbug, you know.”

The Time Traveller smiled round at us. Then, still smiling faintly, and
with his hands deep in his trousers pockets, he walked slowly out of
the room, and we heard his slippers shuffling down the long passage to
his laboratory.

The Psychologist looked at us. “I wonder what he’s got?”

“Some sleight-of-hand trick or other,” said the Medical Man, and Filby
tried to tell us about a conjuror he had seen at Burslem, but before he
had finished his preface the Time Traveller came back, and Filby’s
anecdote collapsed.



A sample post with markdown.

## Inline Highlighting

Sample of inline highlighting `sum = parseInt(num1) + parseInt(num2)`

## Code Blocks

Some Javascript code

```javascript
var num1, num2, sum;
num1 = prompt("Enter first number");
num2 = prompt("Enter second number");
sum = parseInt(num1) + parseInt(num2); // "+" means "add"
alert("Sum = " + sum); // "+" means combine into a string
```

Some Python code 🐍

```python
def fib():
    a, b = 0, 1
    while True:            # First iteration:
        yield a            # yield 0 to start with and then
        a, b = b, a + b    # a will now be 1, and b will also be 1, (0 + 1)

for index, fibonacci_number in zip(range(10), fib()):
     print('{i:3}: {f:3}'.format(i=index, f=fibonacci_number))
```



# Introduction

Markdown and Mdx parsing is supported via `unified`, and other remark and rehype packages. `next-mdx-remote` allows us to parse `.mdx` and `.md` files in a more flexible manner without touching webpack.

GitHub flavored markdown is used. `mdx-prism` provides syntax highlighting capabilities for code blocks. Here's a demo of how everything looks.

The following markdown cheatsheet is adapted from: https://guides.github.com/features/mastering-markdown/

# What is Markdown?

Markdown is a way to style text on the web. You control the display of the document; formatting words as bold or italic, adding images, and creating lists are just a few of the things we can do with Markdown. Mostly, Markdown is just regular text with a few non-alphabetic characters thrown in, like `#` or `*`.

# Syntax guide

Here’s an overview of Markdown syntax that you can use anywhere on GitHub.com or in your own text files.

## Headers

```
# This is a h1 tag

## This is a h2 tag

#### This is a h4 tag
```

# This is a h1 tag

## This is a h2 tag

#### This is a h4 tag

## Emphasis

```
_This text will be italic_

**This text will be bold**

_You **can** combine them_
```

_This text will be italic_

**This text will be bold**

_You **can** combine them_

## Lists

### Unordered

```
- Item 1
- Item 2
  - Item 2a
  - Item 2b
```

- Item 1
- Item 2
  - Item 2a
  - Item 2b

### Ordered

```
1. Item 1
1. Item 2
1. Item 3
   1. Item 3a
   1. Item 3b
```

1. Item 1
1. Item 2
1. Item 3
   1. Item 3a
   1. Item 3b

## Images

```
![GitHub Logo](https://github.githubassets.com/images/modules/logos_page/GitHub-Mark.png)
Format: ![Alt Text](url)
```

![GitHub Logo](https://github.githubassets.com/images/modules/logos_page/GitHub-Mark.png)

## Links

```
http://github.com - automatic!
[GitHub](http://github.com)
```

http://github.com - automatic!
[GitHub](http://github.com)

## Blockquotes

```
As Kanye West said:

> We're living the future so
> the present is our past.
```

As Kanye West said:

> We're living the future so
> the present is our past.

## Inline code

```
I think you should use an
`<addr>` element here instead.
```

I think you should use an
`<addr>` element here instead.

## Syntax highlighting

Here’s an example of how you can use syntax highlighting with [GitHub Flavored Markdown](https://help.github.com/articles/basic-writing-and-formatting-syntax/):

````
```js:fancyAlert.js
function fancyAlert(arg) {
  if (arg) {
    $.facebox({ div: '#foo' })
  }
}
```
````

And here's how it looks - nicely colored with styled code titles!

```js:fancyAlert.js
function fancyAlert(arg) {
  if (arg) {
    $.facebox({ div: '#foo' })
  }
}
```

## Footnotes

```
Here is a simple footnote[^1]. With some additional text after it.

[^1]: My reference.
```

Here is a simple footnote[^1]. With some additional text after it.

[^1]: My reference.

## Task Lists

```
- [x] list syntax required (any unordered or ordered list supported)
- [x] this is a complete item
- [ ] this is an incomplete item
```

- [x] list syntax required (any unordered or ordered list supported)
- [x] this is a complete item
- [ ] this is an incomplete item

## Tables

You can create tables by assembling a list of words and dividing them with hyphens `-` (for the first row), and then separating each column with a pipe `|`:

```
| First Header                | Second Header                |
| --------------------------- | ---------------------------- |
| Content from cell 1         | Content from cell 2          |
| Content in the first column | Content in the second column |
```

| First Header                | Second Header                |
| --------------------------- | ---------------------------- |
| Content from cell 1         | Content from cell 2          |
| Content in the first column | Content in the second column |

## Strikethrough

Any word wrapped with two tildes (like `~~this~~`) will appear ~~crossed out~~.



# Nested Routes

The blog template supports posts in nested sub-folders. This helps in organisation and can be used to group posts of similar content e.g. a multi-part series. This post is itself an example of a nested route! It's located in the `/data/blog/nested-route` folder.

## How

Simplify create multiple folders inside the main `/data/blog` folder and add your `.md`/`.mdx` files to them. You can even create something like `/data/blog/nested-route/deeply-nested-route/my-post.md`

We use Next.js catch all routes to handle the routing and path creations.

## Use Cases

Here are some reasons to use nested routes

- More logical content organisation (blogs will still be displayed based on the created date)
- Multi-part posts
- Different sub-routes for each author
- Internationalization (though it would be recommended to use [Next.js built-in i8n routing](https://nextjs.org/docs/advanced-features/i18n-routing))

## Note

- The previous/next post links at bottom of the template are currently sorted by date. One could explore modifying the template to refer the reader to the previous/next post in the series, rather than by date.



## Introduction

Welcome to the release of Tailwind Nextjs Starter Blog template v2.0. This release is a major refactor of the codebase to support Nextjs App directory and React Server Components. Read on to discover the new features and how to migrate from V1.

<TOCInline toc={props.toc} exclude="Introduction" />

## V1 to V2

![Github Traffic](/static/images/github-traffic.webp)

The template was first released in January 2021 and has since been used by thousands of users. It is featured on [Next.js Templates](https://vercel.com/templates/next.js/tailwind-css-starter-blog), [Tailwind Awesome](https://www.tailwindawesome.com/resources/tailwind-nextjs-starter-blog) among other listing sites. It attracts 200+ unique visitors daily notching 1500-2000 page views, with 1.3k forks and many other clones.

Many thanks to the community of users and contributors for making this template a success! I created a small video montage of the blogs (while cleaning up the list in the readme) to showcase the diversity of the blogs created using the template and to celebrate the milestone:

<video controls>
  <source
    src="https://github-production-user-asset-6210df.s3.amazonaws.com/28362229/258559849-2124c81f-b99d-4431-839c-347e01a2616c.webm"
    type="video/webm"
  />
</video>

Version 2 builds on the success of the previous version and introduces many new features and improvements. The codebase has been refactored to support Next.js App directory and React Server Components. Markdown / MDX is now processed using Contentlayer, a type-safe content SDK that validates and transforms your content into type-safe JSON data. It integrates with Pliny, a new library that provides out of the box Next.js components to enhance your static site with analytics, comments and newsletter subscription. A new command palette (⌘-k) search component is also added to the template.

Let's dive into the new features and improvements in V2.

## Next.js App Directory and React Server Components

Now that [Next.js App router](https://nextjs.org/docs/app) is finally stable and is mostly feature compatible with Page Router, the codebase has been migrated to new setup. This allows for a hybrid rendering approach, with the use of React Server Components generated on the server side for faster page loads and smaller bundle sizes, while retaining the ability to sprinkle in client side React components for interactivity.[^1]

With addition powers comes a [new paradigm](https://nextjs.org/docs/getting-started/react-essentials) to learn. I have migrated the codebase to make use of the new features as much as possible. This includes changes in the folder structure, splitting components into server vs client components, leveraging server side data fetching and using the recommended [Metadata](https://nextjs.org/docs/app/building-your-application/optimizing/metadata) API for SEO discoverability.

While this simplifies the codebase to some extent, it makes migration from the old codebase more difficult. If you are looking to migrate, I recommend starting from a fresh template and copying over your customizations and existing content. See the [migration recommendations](#migration-recommendations) section for more details.

## Typescript First

The codebase has been migrated to Typescript. While the previous version of the template was available in both Javascript and Typescript, I decided to reduce the maintenance burden and focus on Typescript. This also allows for better type checking and code completion in IDEs.

Typescript is also a perfect match with our new type-safe markdown processor - Contentlayer.

## Contentlayer

[Contentlayer](https://www.contentlayer.dev/) is a content SDK that validates and transforms your content into type-safe JSON data that you can easily import into your application. It makes working with local markdown or MDX files a breeze. This replaces `MDX-bundler` and our own markdown processing workflow.

First, a content source is defined, specifiying the name of the document type, the source where it is located along with the frontmatter fields and any additional computed fields that should be generated as part of the process.

```ts:contentlayer.config.ts
export const Blog = defineDocumentType(() => ({
  name: 'Blog',
  filePathPattern: 'blog/**/*.mdx',
  contentType: 'mdx',
  fields: {
    title: { type: 'string', required: true },
    date: { type: 'date', required: true },
    tags: { type: 'list', of: { type: 'string' }, default: [] },
    ...
  },
  computedFields: {
    readingTime: { type: 'json', resolve: (doc) => readingTime(doc.body.raw) },
    slug: {
      type: 'string',
      resolve: (doc) => doc._raw.flattenedPath.replace(/^.+?(\/)/, ''),
    }
    ...
  },
}))
```

Contentlayer then processes the MDX files with our desired markdown remark or rehype plugins, validates the schema, generate type definitions and output json files that can be easily imported in our pages. Hot reloading comes out of the box, so edits to the markdown files will be reflected in the browser immediately!

## Pliny

A large reason for the popularity of the template was its customizability and integration with other services from analytics providers to commenting solutions. However, this means that a lot of boilerplate code has to be co-located within the template even if the user does not use the feature. Updates and bug fixes had to be copied manually to the user's codebase.

To solve this, I have abstracted the logic to a separate repository - [Pliny](https://github.com/timlrx/pliny). Pliny provides out of the box Next.js components to enhance static sites:

- Analytics
  - Google Analytics
  - Plausible Analytics
  - Simple Analytics
  - Umami Analytics
  - Posthog
- Comments
  - Disqus
  - Giscus
  - Utterances
- Newsletter (uses Next 13 API Routes)
  - Buttondown
  - Convertkit
  - Email Octopus
  - Klaviyo
  - Mailchimp
  - Revue
- Command palette search with tailwind style sheet
  - Algolia
  - Kbar (local search)
- UI utility components
  - Bleed
  - Newsletter / Blog Newsletter
  - Pre / Code block
  - Table of Contents

Choose your preferred service by modifying `siteMetadata.js` and changing the appropriate fields. For example to change from Umami Analytics to Plausible, we can change the following fields:

```diff-js:siteMetadata.js
analytics: {
-   umamiAnalytics: {
-     // We use an env variable for this site to avoid other users cloning our analytics ID
-     umamiWebsiteId: process.env.NEXT_UMAMI_ID, // e.g. 123e4567-e89b-12d3-a456-426614174000
-   },
+    plausibleAnalytics: {
+      plausibleDataDomain: '', // e.g. tailwind-nextjs-starter-blog.vercel.app
+    },
},
```

Changes in the configuration file gets propagated to the components automatically. No modification to the template is required.

Under the hood, Pliny exports high level components such as `<Analytics analyticsConfig={analyticsConfig}/>` and `<Comments commentsConfig={commentsConfig}/>` which takes in a configuration object and renders the appropriate component. Since the layouts are defined on the server side, Next.js is able to use the configuration object to determine which component to render and send only the required component bundle to the client.

## New Search Component

What's a blog in 2023 without a command palette search bar?

One of the most highly requested features have been added 🎉! The search component supports 2 search providers - Algolia and Kbar local search.

### Algolia

[Algolia Docsearch](https://docsearch.algolia.com/) is popular free service used across many documentation websites. It automatically scrapes the website that has is submitted for indexing and makes the search result available via a beautiful dialog modal. The pliny component is greatly inspired by the Docusaurus implementation and comes with a stylesheet that is compatible with the Tailwind CSS theme.

### Kbar

[Kbar](https://github.com/timc1/kbar) is a fast, portable, and extensible cmd+k interface. The pliny implementation uses kbar to create a local search dialog box. The component loads a JSON file, default `search.json`, that was created in the contentlayer build process. Try pressing ⌘-k or ctrl-k to see the search bar in action!

## Styling and Layout Updates

### Theming

`tailwind.config.js` has been updated to use tailwind typography defaults where possible and to use the built-in support for dark mode via the `prose-invert` class. This replaces the previous `prose-dark` class and configuration.

The primary theme color is updated from `teal` to `pink` and the primary gray theme from `neutral` to `gray`.

Inter is now replaced with Space Grotesk as the default font.

### New Layouts

Layout components available in the `layouts` directory, provide a simple way to customize the look and feel of the blog.[^2]

The downside of building a popular template is that you start seeing multiple similar sites everywhere 😆. While users are encouraged to customized the layouts to their liking, having more layout options that are easily switchable promotes diversity and perhaps can be a good starting point for further customizations.

In v2, I added a new post layout - `PostBanner`. It features a large banner image and a centered content container. Check out "[Pictures of Canada](/blog/pictures-of-canada)" blog post which has been updated to use the new layout.

The default blog listing layout has also been updated to include a side bar with blog tags. The search bar in the previous layout has been replace with the new command palette search. To switch back to the old layout, simply change the pages that use the `ListLayoutWithTags` component back to the original `ListLayout`.

## Migration Recommendations

Due to the large changes in directory structure, setup and tooling, I recommend starting from a fresh template and copying existing content, followed by incrementally migrating changes over to the new template.

Styling changes should be relatively minor and can be copied over from the old `tailwind.config.js` to the new one. If copying over, you might need to add back the `prose-dark` class to components that opt into tailwind typography styling. Do modify the font import in the root layout component to use the desired font of choice.

Changes to the MDX processing pipeline and schema can be easily ported to the new Contentlayer setup. If there are changes to the frontmatter fields, you can modify the document type in `contentlayer.config.ts` to include the new fields. Custom plugins can be added to the `remarkPlugins` and `rehypePlugins` properties in the `makeSource` export of `contentlayer.config.ts`.

Markdown layouts are no longer sourced automatically from the `layouts` directory. Instead, they have to be specified in the `layouts` object defined in `blog/[...slug]/page.tsx`.[^3]

To port over larger components or pages, I recommend first specificing it as a client component by using the `"use client"` directive. Once it renders correctly, you can split the interactive components (parts that rely on `use` hooks) as a client component and keep the remaining code as a server component. Consult the comprehensive Next.js [migration guide](https://nextjs.org/docs/app/building-your-application/upgrading/app-router-migration#migrating-from-pages-to-app) for more details.

## Conclusion

I hope you enjoy the new features and improvements in V2. If you have any feedback or suggestions, feel free to open an issue or reach out to me on [Twitter](https://twitter.com/timlrx).

## Support

Using the template? Support this effort by giving a star on GitHub, sharing your own blog and giving a shoutout on Twitter or be a project [sponsor](https://github.com/sponsors/timlrx).

## Licence

[MIT](https://github.com/timlrx/tailwind-nextjs-starter-blog/blob/main/LICENSE) © [Timothy Lin](https://www.timrlx.com)

[^1]: The previous version injects Preact into the production build. However, this is no longer possible as it does not support React Server Components. While overall bundle size has increased to about 85kB, most of the content can be pre-rendered on the server side, resulting in a low first contentful paint and time to interactive. Using React throughtout also leads to more consistent behavior with external libraries and components.
[^2]: This is different from Next.js App Directory layouts and are best thought of as reusable React containers.
[^3]: This takes advantage of Server Components by making it simple to specify the layout of choice in the markdown file and match against the `layouts` object which is then used to render the appropriate layout component.


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