
__Framer Motion makes it super easy to create great looking animations, but what if you want to have different animations for different screen sizes? In pure css you can just use a media query but did you know that by utilising the Window.matchMedia API you can use media queries in javascript too? This way we can write responsive animations for javascript animation libraries like Framer Motion & React Spring.__

## Using media queries in javascript

The easiest way to get started with the [window.matchMedia API](https://developer.mozilla.org/en-US/docs/Web/API/Window/matchMedia) in React is to create a custom hook. A lot of UI frameworks like [Material UI](https://material-ui.com/components/use-media-query/) and [Chakra UI](https://chakra-ui.com/docs/hooks/use-media-query) already exposes such a hook, but here's what it could look like if you would write your own:

```jsx
export function useMediaQuery(query) {
  const [matches, setMatches] = useState(false);

  useEffect(() => {
    const media = window.matchMedia(query);
    if (media.matches !== matches) {
      setMatches(media.matches);
    }
    const listener = () => {
      setMatches(media.matches);
    };
    media.addListener(listener);
    return () => media.removeListener(listener);
  }, [matches, query]);

  return matches;
}
```

It takes a media query string (the same way you would write it in css) and returns `true` if the query matches the current screen. If the screen is resized the value will update. Use it in code like this:

```jsx
 const isSmall = useMediaQuery('(min-width: 480px)');
```

A good idea is to set up custom hooks matching the media queries you already use in your css so you don't have to remember the pixel values (was it 479 or 480?):

```jsx
export const useIsSmall = () => useMediaQuery('(min-width: 480px)');
export const useIsMedium = () => useMediaQuery('(min-width: 768px)');

/* etc.. /*
```

## Responsive Animation with Variants

Now that we have our hooks setup lets put it all together by making an example using variants to conditionally change based on the media query.

```jsx
import { motion } from 'framer-motion'
import { useIsSmall } from 'src/hooks/utils'

const Component = () => {
	const isSmall = useIsSmall() /* or useMediaQuery('(min-width: 480px)'); */
 
	const variants = isSmall
	? {
	    animate: {
	      opacity: 1,
	      scale: 1,
				y: 0,
	    },
	    exit: {
	      opacity: 1,
	      scale: 1,
				y: 500,
	    },
	  }
	: {
	    animate: {
	      opacity: 1,
	      scale: 1,
	      y: 0,
	    },
	    exit: {
	      opacity: 0,
	      scale: 0.9,
	      y: -10,
	    },
	  };
	
	return (
		<motion.div initial="exit" animate="animate" exit="exit">Animated</div>
	);
}
```

That's it 🙌. You can also use the variable inline `<motion.div animate={isSmall ? { y: 500} : { y: 1000}} />` but I find that using it together with variants is the cleanest way most of the time.




**Ever wanted to use Notion as a blog CMS? This guide will walk you through how to setup Notion for blogging and how to access the data using Notions public API.**

Notions public API is finally here! I put together [an example repo](https://github.com/samuelkraft/notion-blog-nextjs) on creating a blog using **Notion as a CMS** hours after the release and was blown away by the interest so here's a guide explaining how to set it up yourself using the new api & Next.js.

## Getting started

If you're new to the notion API the first thing you need to do in order to start using it is to retrieve a `NOTION_TOKEN` by following their [Getting Started guide](https://developers.notion.com/docs/getting-started). When following the guide create either a table or a list as the database for your content. After finishing you should have a `NOTION_TOKEN` as well as a database id.

Create a Next.js project by following the [Next.js app setup](https://nextjs.org/learn/basics/create-nextjs-app/setup). The neat thing about using Next.js is that you can statically render all blog posts, while still updating them with *incremental static generation* making your blog super snappy ⚡️.

<Warning type="info">
  This guide assumes you are using Next.js but you can use plain javascript or whatever framework you wish, the Notion code is the same.
</Warning>

Save your `NOTION_TOKEN` and `NOTION_TABLE_ID` to a `.env.local` file in your projects root directory, then install their javascript client by running `yarn add @notionhq/client` .

## Fetching data using Notions javascript client

Let's create a new file called `lib/notion.js` which will contain all our API usage. To fetch our data we first need to create a client and supply it with the token we received earlier

```jsx
import { Client } from "@notionhq/client";

const notion = new Client({
  auth: process.env.NOTION_TOKEN,
});
```

Then we need to add the functions we need. To get a list of our posts we need to be able to query a specific database (`getDatabase`), to get the information for a specific post we need to get a specific page (`getPage`), and to actually get the content of the page we need get its blocks (`getBlocks`).   

```jsx{7-25}
import { Client } from "@notionhq/client";

const notion = new Client({
  auth: process.env.NOTION_TOKEN,
});

export const getDatabase = async (databaseId) => {
  const response = await notion.databases.query({
    database_id: databaseId,
  });
  return response.results;
};

export const getPage = async (pageId) => {
  const response = await notion.pages.retrieve({ page_id: pageId });
  return response;
};

export const getBlocks = async (blockId) => {
  const response = await notion.blocks.children.list({
    block_id: blockId,
    page_size: 50,
  });
  return response.results;
};
```

## Showing a list of posts

Add a function called `getInitialProps` to `pages/index.js` where you use the getDatabase function to fetch all posts. The response will contain a [Database Object](https://developers.notion.com/reference/database) containing information like the database title, when it was last edited as well as its properties (in our case blogposts).

<Warning type="info">
  If you're new to Next.js getStaticProps allows you to pre-render the page at build time using the props returned by the function. Combining this with the revalidate prop will allow the page to get updated in the background as new traffic comes in without the need to rebuild your entire site. Learn more about <a href="https://nextjs.org/docs/basic-features/data-fetching#incremental-static-regeneration">Incremental Static Generation</a>.
</Warning>

```jsx
import Link from "next/link";
import { getDatabase } from "../lib/notion";
import { Text } from "./[id].js";

export const databaseId = process.env.NOTION_DATABASE_ID

export default function Home({ posts }) {
  return (  
    <ol className={styles.posts}>
      {posts.map((post) => (
        <li key={post.id}>
          <Link href={`/${post.id}`}>
             <Text text={post.properties.Name.title} />
          </Link>
        </li>
      ))}
    </ol> 
  );
}

export const getStaticProps = async () => {
  const database = await getDatabase(databaseId);

  return {
    props: {
      posts: database,
    },
		// Next.js will attempt to re-generate the page:
    // - When a request comes in
    // - At most once every second
    revalidate: 1, // In seconds
  };
};
```

<Warning type="info">
We're using the post id as slug for sake of simplicity in this tutorial. For SEO purposes it would be better to use a prettier slug based on the title. You can do this by either manually adding a slug property to each post in Notion or generating a slug with a package like <a href="https://www.npmjs.com/package/slugify">slugify</a>.
</Warning>

Uhm, what is that `<Text />` component you might ask? Notion has a lot of rich text tools allowing you to **format** <ins>text</ins> ~~like~~ *this,* so instead of just returning a plain text value each text-like field returns an array of [Rich text objects](https://developers.notion.com/reference/rich-text) like this:

```jsx
{
  annotations: {
    bold: false,
    italic: false,
    strikethrough: false,
    underline: false,
    code: false,
    color: 'default'
  },
  href: null,
  plain_text: "Hello world!",
  text: {
    content: "Hello world!",
    link: null
  },
  type: "text"
}
```

In order to handle links and annotations let's create a component that we can re-use for all types of text:

```jsx
import styles from './text.module.css'

export const Text = ({ text }) => {
  if (!text) {
    return null;
  }
  return text.map((value) => {
    const {
      annotations: { bold, code, color, italic, strikethrough, underline },
      text,
    } = value;
    return (
      <span
        className={[
          bold ? styles.bold : "",
          code ? styles.code : "",
          italic ? styles.italic : "",
          strikethrough ? styles.strikethrough : "",
          underline ? styles.underline : "",
        ].join(" ")}
        style={color !== "default" ? { color } : {}}
      >
        {text.link ? <a href={text.link.url}>{text.content}</a> : text.content}
      </span>
    );
  });
};
```

```css
.bold {
  font-weight: bold;
}

.code {
  font-family: monospace;
  background-color: rgb(242, 242, 242);
  padding: 2px 4px;
  border-radius: 2px;
}

.italic {
  font-style: italic;
}

.strikethrough {
  text-decoration: line-through;
}

.underline {
  text-decoration: underline;
}
```

## Showing a specific post

Let's create a `pages/[id].js` page that will show the content of each blog post

```jsx
import { Fragment } from "react";
import { getDatabase, getPage, getBlocks } from "../lib/notion";
import { databaseId } from "./index.js";
import Text from 'components/text'

const renderBlock = (block) => {
  const { type, id } = block;
  const value = block[type];

  switch (type) {
    case "paragraph":
      return (
        <p>
          <Text text={value.text} />
        </p>
      );
    case "heading_1":
      return (
        <h1>
          <Text text={value.text} />
        </h1>
      );
    case "heading_2":
      return (
        <h2>
          <Text text={value.text} />
        </h2>
      );
    case "heading_3":
      return (
        <h3>
          <Text text={value.text} />
        </h3>
      );
    case "bulleted_list_item":
    case "numbered_list_item":
      return (
        <li>
          <Text text={value.text} />
        </li>
      );
    case "to_do":
      return (
        <div>
          <label htmlFor={id}>
            <input type="checkbox" id={id} defaultChecked={value.checked} />{" "}
            <Text text={value.text} />
          </label>
        </div>
      );
    case "toggle":
      return (
        <details>
          <summary>
            <Text text={value.text} />
          </summary>
          {value.children?.map((block) => (
            <Fragment key={block.id}>{renderBlock(block)}</Fragment>
          ))}
        </details>
      );
    case "child_page":
      return <p>{value.title}</p>;
    case "image":
      const src =
        value.type === "external" ? value.external.url : value.file.url;
      const caption = value.caption ? value.caption[0].plain_text : "";
      return (
        <figure>
          <img src={src} alt={caption} />
          {caption && <figcaption>{caption}</figcaption>}
        </figure>
      );
    default:
      return `❌ Unsupported block (${
        type === "unsupported" ? "unsupported by Notion API" : type
      })`;
  }
};

export default function Post({ page, blocks }) {
  if (!page || !blocks) {
    return <div />;
  }
  return (   
    <article>
      <h1>
        <Text text={page.properties.Name.title} />
      </h1>
      <section>
        {blocks.map((block) => (
          <Fragment key={block.id}>{renderBlock(block)}</Fragment>
        ))}
      </section>
    </article>
  );
}

export const getStaticPaths = async () => {
  const database = await getDatabase(databaseId);
  return {
    paths: database.map((page) => ({ params: { id: page.id } })),
    fallback: true,
  };
};

export const getStaticProps = async (context) => {
  const { id } = context.params;
  const page = await getPage(id);
  const blocks = await getBlocks(id);

  // Retrieve block children for nested blocks (one level deep), for example toggle blocks
  // https://developers.notion.com/docs/working-with-page-content#reading-nested-blocks
  const childBlocks = await Promise.all(
    blocks
      .filter((block) => block.has_children)
      .map(async (block) => {
        return {
          id: block.id,
          children: await getBlocks(block.id),
        };
      })
  );
  const blocksWithChildren = blocks.map((block) => {
    // Add child blocks if the block should contain children but none exists
    if (block.has_children && !block[block.type].children) {
      block[block.type]["children"] = childBlocks.find(
        (x) => x.id === block.id
      )?.children;
    }
    return block;
  });

  return {
    props: {
      page,
      blocks: blocksWithChildren,
    },
    revalidate: 1,
  };
};
```

That's a lot, so let's break it down starting from the bottom.

Just as on the index page we are using getStaticProps to get the data so the page can be statically rendered. In order to know which post to render we'll use the `context` parameter which contains route parameters for the current page. With the post id we can then use our two notion functions `getPage()` and `getBlocks()` and return the results as props to our component.

For performance reasons any nested child blocks won't be returned with the original call. If you need to get a complete representation including child blocks (for example toggle blocks) then you need to run the getBlocks function for each block containing the `has_children` property. When you have received all the children you can then merge the original blocks array with the childblock data (`blocksWithChildren`).


When using dynamic routes we also need to specify a list of availables routes and we'll do that with `getStaticPaths` by mapping over the pages and returning the page id's.

## Rendering Notion blocks

The `blocks` prop contains a list of all the blocks as [Block Objects](https://developers.notion.com/reference/block). We have created a `renderBlock()` function that will take care of displaying the different blocks.

```jsx
switch (type) {
  case "paragraph":
    return (
      <p>
        <Text text={value.text} />
      </p>
    );
  case "heading_1":
    return (
      <h1>
        <Text text={value.text} />
      </h1>
    );
  case "heading_2":
		…
```

Open up the index page in your browser and click a post and you should see a working page displaying your content!

## Notion API unsupported blocks

During the Notion API beta unfortunately not all block types are supported. The supported block types are:

- `paragraph`
- `heading_1`
- `heading_2`
- `heading_3`
- `bulleted_list_item`
- `numbered_list_item`
- `to_do`
- `toggle`

*Update 2020/08/24* - New media block types added:
- `child_page`
- `image`
- `embed`
- `video`
- `file`
- `pdf`
- `bookmark`

If you use a block that is not supported the page will display `❌ Unsupported block`. At this time there's no way of getting around this other than using their private API which is not recommended and can change at any time. If you need more blocks than those available right now I would wait a little bit longer until all block types are available.

## Styling

This guide intentionally comes without any styles as you would probably just rip it out anyways. If you want inspiration I put together some very bare-bones styles [in my example repo at GitHub](https://github.com/samuelkraft/notion-blog-nextjs).

## That's it!

You now have a blog powered by Notion! If you add a new blogpost or edit a post then the page will automatically get updated on the second hit thanks to Next.js incremental static regeneration. Check out my [live example here](https://notion-blog-nextjs-coral.vercel.app) and let me know if you enjoyed this post by pressing ❤️ below or pinging me [on twitter](https://twitter.com/samuelkraft)

<Image
  alt="Blog powered by Notion and Next.js"
  caption="Blog powered by Notion and Next.js"
  src={'/blog/building-a-notion-blog-with-public-api/screenshot.png'}
  width={2216}
  height={1504}
/>



Mapbox is one of the nicest way to embed custom dynamic maps in an app as there are lots of customisation options. I'm using their service on my route exploration website [Trail Router](https://routes.kevchentw.com) to display running & hiking routes from gpx files. In this post I'll go over how I used Mapbox's [static image api](https://docs.mapbox.com/help/glossary/static-images-api/) and [Node Canvas](https://github.com/Automattic/node-canvas) to create custom og sharing images like the example below:

<Image
  alt="Nyckelviken Trail Route"
  caption="Custom Open Graph Image for Nyckelviken Trail Route"
  src={'/blog/mapbox-static-image-api/nyckelviken.png'}
  width={1012}
  height={516}
/>

The code used looks like this:
```jsx
const fs = require('fs')
const path = require('path')
const gp = require('geojson-precision')
const simplify = require('simplify-geojson')
const polyline = require('@mapbox/polyline')
const { createCanvas, loadImage } = require('canvas')
const { routes } = require('../utils/gpxutils.js')

const width = 1012
const height = 516

async function generate() {
  await Promise.all(
    routes.map(async route => {
      // simplify the geojson and strip extra points from coordinates to fit mapbox's api
      const geoJson = simplify(gp(route.geoJson, 4), 0.0001)
      // Encode our geoJson to a polyline - replace any "?" with encoded value or mapbox will break
      const poly = polyline.fromGeoJSON(geoJson.features[0].geometry).replace(/\?/g, '%3F')
      // Mapbox wants a hash-less hex value
      const color = route.color.replace('#', '')
      const padding = '80, 80, 120'
      const mapboxImage = `https://api.mapbox.com/styles/v1/mapbox/outdoors-v11/static/path-5+${color}-1(${poly})/auto/${width}x${height}?padding=${padding}&access_token=${process.env.NEXT_PUBLIC_MAPBOX_ACCESS_TOKEN}`

      const canvas = createCanvas(width, height)
      const context = canvas.getContext('2d')

      // Load the mapbox image onto a canvas
      const map = await loadImage(mapboxImage)
      context.drawImage(map, 0, 0)

      // Add gradient in the bottom so overlayed text is visible
      const gradient = context.createLinearGradient(0, height * 0.7, 0, height)
      gradient.addColorStop(0, 'rgba(0,0,0,0)')
      gradient.addColorStop(1, 'rgba(0,0,0,0.5)')
      context.fillStyle = gradient
      context.fillRect(0, height * 0.7, width, height)

      // Add image in top corner
      const logo = await loadImage('./public/logo.png')
      context.drawImage(logo, 40, 40)

      const titleY = 470
      const labelY = titleY - 45
      const distanceX = 40
      const elevationX = width * 0.25 + distanceX
      const stifaX = width * 0.5 + distanceX
      const ratingX = width * 0.75 + distanceX

      // Add titles
      context.fillStyle = '#fff'
      context.font = 'bold 30pt Proxima Nova'
      context.fillText(`${Math.round(route.distance * 10) / 10} km`, distanceX, titleY)
      context.fillText(`${Math.round(route.elevation)} m`, elevationX, titleY)
      context.fillText(`${Math.round(route.elevation / route.distance)}`, stifaX, titleY)
      context.fillText(`${route.rating}/5`, ratingX, titleY)

      // Add labels
      context.font = 'bold 16pt Proxima Nova'
      context.fillText(`DISTANCE`, distanceX, labelY)
      context.fillText(`ELEVATION`, elevationX, labelY)
      context.fillText(`STIFA`, stifaX, labelY)
      context.fillText(`RATING`, ratingX, labelY)

      const buffer = canvas.toBuffer('image/png')
      fs.writeFileSync(path.join(process.cwd(), `public/og/${route.slug}.png`), buffer)
    }),
  )
}

generate()
```

That's quite a lot to take in so let's break it down step by step!

## Setup

In order to use Mapbox static image api you first need an access token. If you don't already have one you can get one from your [account page](https://account.mapbox.com/access-tokens/). 

The [Static Image API](https://docs.mapbox.com/help/glossary/static-images-api/) allows us to request a static map by providing a couple of parameters like coordinates & zoom level, but you can also add layers like paths and geoJson. 

Here's an example of a map generated with the following code:

```js
https://api.mapbox.com/styles/v1/mapbox/streets-v11/static/
-122.337798,37.810550,9.67,0.00,0.00/1000x600?access_token=${MAPBOX_ACCESS_TOKEN}
```

<Image
  alt="Mapbox Static Api Example image"
  src={'/blog/mapbox-static-image-api/example.png'}
  width={1000}
  height={600}
/>

First we have specified the style of the map, in this case `streets-v11`. [Their documentation](https://docs.mapbox.com/api/maps/styles/#mapbox-styles) lists all the available styles. I've mainly used the `outdoors-v11` style but you can also desig a custom one specific for your needs. 

In this example we have used specific coordinates to specify what we want rendered but we can also make our map automatically fit the bounds to whatever is displayed, like geoJson or a path with the `auto` paramter.

## Using Mapbox's static api with geoJson

Our route data is in the form of a geoJson object. Check out my article [Building a mapping platform with React and Mapbox GL](https://kevchentw.com/blog/trailroutes) for details how to parse geoJson from gpx files.

The api supports geoJson using a `geoJson=({})` parameter, however it only accepts 8,192 or fewer characters. Even after simplifying the geojson and removing redundant coordinates to get it below the limit I did not manage to get it working. Instead I opted for the [Path](https://docs.mapbox.com/api/maps/static-images/#path) parameter which looks like this and accepts an encoded polyline:

```jsx
path-{strokeWidth}+{strokeColor}-{strokeOpacity}+{fillColor}-{fillOpacity}({polyline})
```

## Encoding geoJson to polyline

To create a polyline from geoJson we can use mapbox's polyline package. In order to make the polyline a bit more lean we can also simplify it with simplify-geojson and geojson-precision.

```jsx
const gp = require('geojson-precision')
const simplify = require('simplify-geojson')
const polyline = require('@mapbox/polyline')

routes.map(async route => {
  // simplify the geojson and strip extra points from coordinates to fit mapbox's api
  const geoJson = simplify(gp(route.geoJson, 4), 0.0001)
  // Encode our geoJson to a polyline - replace any "?" with encoded value or mapbox will break
  const poly = polyline.fromGeoJSON(geoJson.features[0].geometry).replace(/\?/g, '%3F')
})
```

<Warning type="info">
  It took me a while to figure out that the api does not accept polylines containing question marks "<strong>?</strong>" as that breaks the url parameters. Be sure to replace all instances with it's encoded counterpart.
</Warning>

Another thing we need to do is remove the `#` from the color we wish to have, specify the width and height and how much padding we want.

```jsx{10-15}
const gp = require('geojson-precision')
const simplify = require('simplify-geojson')
const polyline = require('@mapbox/polyline')

routes.map(async route => {
  // simplify the geojson and strip extra points from coordinates to fit mapbox's api
  const geoJson = simplify(gp(route.geoJson, 4), 0.0001)
  // Encode our geoJson to a polyline - replace any "?" with encoded value or mapbox will break
  const poly = polyline.fromGeoJSON(geoJson.features[0].geometry).replace(/\?/g, '%3F')
  // Mapbox wants a hash-less hex value
  const color = route.color.replace('#', '')
  // Extra padding in the bottom to make space for text
  const padding = '80, 80, 120'
  const width = 1012
  const height = 516
})
```

Now let's use the polyline in the api url and we have a working map 🎉

```jsx{16}
const gp = require('geojson-precision')
const simplify = require('simplify-geojson')
const polyline = require('@mapbox/polyline')

routes.map(async route => {
  // simplify the geojson and strip extra points from coordinates to fit mapbox's api
  const geoJson = simplify(gp(route.geoJson, 4), 0.0001)
  // Encode our geoJson to a polyline - replace any "?" with encoded value or mapbox will break
  const poly = polyline.fromGeoJSON(geoJson.features[0].geometry).replace(/\?/g, '%3F')
  // Mapbox wants a hash-less hex value
  const color = route.color.replace('#', '')
  // Extra padding in the bottom to make space for text
  const padding = '80, 80, 120'
  const width = 1012
  const height = 516
  const mapboxImage = `https://api.mapbox.com/styles/v1/mapbox/outdoors-v11/static/path-5+${color}-1(${poly})/auto/${width}x${height}?padding=${padding}&access_token=${MAPBOX_ACCESS_TOKEN}`
})
```

## Adding text on the image with node canvas

In order to add metadata like distance, elevation and logo on top of the image we can use [node-canvas](https://github.com/Automattic/node-canvas). It implements the web canvas API as closely as possible and is perfect for this use case. 

If you have ever used Sketch, Photoshop or another application that uses layers you can think of canvas the same way. What is written first (bottom of the layers list in sketch) is the bottom layer, and everthing after that is stacked on top. 

<Image
  alt="Sketch layers example"
  caption="Layers in Sketch"
  src={'/blog/mapbox-static-image-api/layers.png'}
  width={1406}
  height={592}
/>

In the code below I am adding a gradient *before* I add the text, that way the gradient will be positioned beneath the text in the final image.

I have commented what each line does in the code below. 

```jsx
// Create a canvas context the same size as out mapbox image
const canvas = createCanvas(width, height)
const context = canvas.getContext('2d')

// Load the mapbox image onto a canvas
const map = await loadImage(mapboxImage)
context.drawImage(map, 0, 0)

// Add gradient in the bottom so overlayed text is visible
const gradient = context.createLinearGradient(0, height * 0.7, 0, height)
gradient.addColorStop(0, 'rgba(0,0,0,0)')
gradient.addColorStop(1, 'rgba(0,0,0,0.5)')
context.fillStyle = gradient
context.fillRect(0, height * 0.7, width, height)

// Add logo in top left corner
const logo = await loadImage('./public/logo.png')
context.drawImage(logo, 40, 40)

// Specify the positions of the text overlays
const titleY = 470
const labelY = titleY - 45
const distanceX = 40
const elevationX = width * 0.25 + distanceX
const stifaX = width * 0.5 + distanceX
const ratingX = width * 0.75 + distanceX

// Add titles
context.fillStyle = '#fff'
context.font = 'bold 30pt Proxima Nova'
context.fillText(`${Math.round(route.distance * 10) / 10} km`, distanceX, titleY)
context.fillText(`${Math.round(route.elevation)} m`, elevationX, titleY)
context.fillText(`${Math.round(route.elevation / route.distance)}`, stifaX, titleY)
context.fillText(`${route.rating}/5`, ratingX, titleY)

// Add labels
context.font = 'bold 16pt Proxima Nova'
context.fillText(`DISTANCE`, distanceX, labelY)
context.fillText(`ELEVATION`, elevationX, labelY)
context.fillText(`STIFA`, stifaX, labelY)
context.fillText(`RATING`, ratingX, labelY)

const buffer = canvas.toBuffer('image/png')
// Write the image to a specified directory
fs.writeFileSync(path.join(process.cwd(), `public/og/${route.slug}.png`), buffer)
```

That's it! Find the full source code [here](https://github.com/samuelkraft/routes/blob/master/scripts/generate-images.js) and check out a few examples of images I generated:

<Image
  alt="A-trail + Gröna Trail Route"
  caption="A-trail + Gröna Trail Route"
  src={'/blog/mapbox-static-image-api/grona_atrail.png'}
  width={1012}
  height={516}
/>

<Image
  alt="Nyckelviken Trail Route"
  caption="Nyckelviken Trail Route"
  src={'/blog/mapbox-static-image-api/nyckelviken.png'}
  width={1012}
  height={516}
/>

<Image
  alt="Booleden + Värmdöleden Trail Route"
  caption="Booleden + Värmdöleden Trail Route"
  src={'/blog/mapbox-static-image-api/booleden_varmdoleden.png'}
  width={1012}
  height={516}
/>

If you liked this post please let me know by pressing ❤️ below!


I built <a href="https://routes.kevchentw.com">Trail Routes</a> as a way to share some of the best running & hiking routes I've discovered, and in this post I will outline the build process.

## The goal
My goal was to show a list of routes I enjoy coupled with basic information like distance, elevation gain and my rating. The routes should be visible on a map, and clicking a route should display more information about it, including an elevation map. There should be a way to download each route as a gpx file.
<Warning type="info">
    A gpx file is basically an xml file consisting of coordinates that forms a route. It can also contain other information like heart rate data and elevation if created from an activity. You can transfer gpx files to most modern sport watches and get navigation features.
</Warning> 

I opened up Sketch to create a logo and a few mockups of the interface:

<Image
  alt="Trail Routes logo"
  caption="Logotype"
  src={'/blog/trailroutes/logo.png'}
  width={1416}
  height={707}
/>
<Image
  alt="Trail Routes main view mockup"
  caption="Main view"
  src={'/blog/trailroutes/trailroutes-mockup.png'}
  width={1416}
  height={707}
/>
<Image
    alt="Trail Routes detail view mockup"
    caption="Detail view"
    src={'/blog/trailroutes/trailroutes-mockup-detail.png'}
    width={1416}
    height={707}
/>

## Getting the route data
I create all my routes with Stravas Route builder tool which uses Mapbox so that seemed like a great choice for me as well. In order to display things on a Mapbox map you need the data as a geoJson object. My first idea was to use the strava API to fetch the routes I've created, which then returns the data in a mapbox-friendly format. This didn't work very well because I have created TONS of routes on Strava, and unfortunately there's no way to tag or categorise them so I started looking at alternatives. 

That's when I found Mapbox's package [toGeoJson](https://github.com/mapbox/togeojson) that takes a GPX file and converts it to geoJson, just what is needed! The code below looks at a public/gpx folder, maps over the files and pulls out the geoJson and creates a slug for each route.

```jsx
import toGeoJson from '@mapbox/togeojson'
import { DOMParser } from 'xmldom'
import path from 'path'
import fs from 'fs'

const ROUTES_PATH = path.join(process.cwd(), 'public', 'gpx')

const routes = routeFilePaths.map(filePath => {
    const source = new DOMParser().parseFromString(fs.readFileSync(path.join(ROUTES_PATH, filePath), 'utf8'))
    const geoJson = toGeoJson.gpx(source)
    const slug = filePath.replace('.gpx', '')

    return {
        geoJson, slug	
    }
})
```

## Calculate geoJson distance with Turf.js

The gpx files from Strava only contains cordinates and some basic metadata, but we're missing distance and total elevation. Luckily we can use an amazing open-source project called [Turf.js](http://turfjs.org) to do lots of advanced analysis on our geoJson. Look how easily we can calculate the total distance of the geoJson using [@turfjs/length](https://www.npmjs.com/package/@turf/length):

```jsx{5,14-15,18}
import toGeoJson from '@mapbox/togeojson'
import { DOMParser } from 'xmldom'
import path from 'path'
import fs from 'fs'
import length from '@turf/length'

const ROUTES_PATH = path.join(process.cwd(), 'public', 'gpx')

const routes = routeFilePaths.map(filePath => {
    const source = new DOMParser().parseFromString(fs.readFileSync(path.join(ROUTES_PATH, filePath), 'utf8'))
    const geoJson = toGeoJson.gpx(source)
    const slug = filePath.replace('.gpx', '')

    // Calculate distance using geoJson
    const distance = length(geoJson)

    return {
        geoJson, slug, distance
    }
})
```

## Parse elevation data from geoJson

The original gpx file from strava contains the current elevation for each point, so in order to calculate the total elevation gain we simply map over the coordinates and sum the difference between each as explained in [this article](https://www.gpsvisualizer.com/tutorials/elevation_gain.html). Credit to Taylor Callsen's [initial implemention](https://github.com/tcallsen/geoCalcLineElevation).

```jsx{9-16,19}
const routes = routeFilePaths.map(filePath => {
    const source = new DOMParser().parseFromString(fs.readFileSync(path.join(ROUTES_PATH, filePath), 'utf8'))
    const geoJson = toGeoJson.gpx(source)
    const slug = filePath.replace('.gpx', '')

    // Calculate distance using geoJson
    const distance = length(geoJson)

    // Calculate elevation gain using coordinate data
    const { coordinates } = geoJson.features[0].geometry
    let elevation = 0
    coordinates.forEach((coord, index) => {
      if (index === coordinates.length - 1) return // stop 1 point early since comparison requires 2 points
      const elevationDifference = coordinates[index + 1][2] - coordinates[index][2]
      if (elevationDifference > 0) elevation += elevationDifference
    })

    return {
        geoJson, slug, distance, elevation
    }
})
```

That's a lot of parsing and calculation! 😅 I now realized that my choice of using Next.js was a perfect fit for the project. All the parsing can be done at build time inside getInitialProps, and then I can serve a static cached version of the site for all visitors. 

## Displaying geoJson with Mapbox GL and React

I used the excellent guide from the Mapbox docs on [creating a mapbox react component](https://docs.mapbox.com/help/tutorials/use-mapbox-gl-js-with-react/). Mapbox's outdoor map is perfect for this use-case and can be accessed by setting the style to outdoors:
```jsx{3}
const map = new mapboxgl.Map({
    container: mapContainer.current,
    style: 'mapbox://styles/mapbox/outdoors-v11',
    center: [lng, lat],
    zoom,
  })
```

We want to add all our geoJson to the map when it has finished loading by mapping over the routes in a `map.on('load')` callback. 

There's two steps to displaying geoJson on the map:

1. Add the source
2. Add a layer using that source

```jsx
map.on('load', () => {
  routes.forEach((route: Route) => {
    const { slug } = route
	// 1. Add the source using the slug as unique id
    map.addSource(slug, {
      type: 'geojson',
      data: route.geoJson,
    })

    // 2. Add a layer displaying our route
    map.addLayer({
      id: slug,
      type: 'line',
      source: slug, // same id as above
      layout: {
        'line-join': 'round',
        'line-cap': 'round',
      },
      paint: {
        'line-color': 'red',
        'line-width': 4,
      },
    })
})
```

We should now have a map showing all our routes 🎉 Right now the color is hardcoded to red, in order differentiate we need to specify a color for each route. In my case I'm saving some extra metadata in a javascript file including a custom color for each:

```js{8,14}
const colors = require('tailwindcss/colors')

export const meta = {
  nyckelviken: {
    description: '…',
    rating: 5,
    location: 'Nacka · Stockholm',
    color: colors.blue[500],
  },
  hellasgarden_gula: {
    description: '…',
    rating: 5,
    location: 'Nacka · Stockholm',
    color: colors.yellow[300],
  }
}
```
```jsx{10}
map.addLayer({
  id: slug,
  type: 'line',
  source: slug,
  layout: {
    'line-join': 'round',
    'line-cap': 'round',
  },
  paint: {
    'line-color': color,
    'line-width': 4,
  },
})
```

## Updating our mapbox map with react

The final feature for our map component is to be able to click each route and the map to zoom in to just that route.
In order to get a bigger click area than just the line we added before we can add a transparent fill inside each route:

```jsx
// Add a fill layer as source for hover, or we lose our click target when inside the path
map.addLayer({
  id: `${slug}-fill`,
  type: 'fill',
  source: slug,
  paint: {
    'fill-color': 'transparent',
    'fill-outline-color': 'transparent',
  },
})
```

Then when we hover and click that element we can trigger an action, in this case updating our query.

```jsx

map.on('mouseenter', `${slug}-fill`, () => {
  // Change the cursor style as a UI indicator.
  map.getCanvas().style.cursor = 'pointer'
  // Increase width of route path
  map.setPaintProperty(slug, 'line-width', 6)
})

map.on('mouseleave', `${slug}-fill`, () => {
  map.getCanvas().style.cursor = ''
  map.setPaintProperty(slug, 'line-width', 4)
})

map.on('click', `${slug}-fill`, () => {
  const coords = route.geoJson.features[0].geometry.coordinates
  // Calculate the bounds to know where to zoom to
  const bounds = coords.reduce((b, coord) => {
    return b.extend(coord)
  }, new mapboxgl.LngLatBounds(coords[0], coords[0]))

  // Fit map to bounds/route
  map.fitBounds(bounds, {
    padding: 20,
  })
	
  // Update the query
  router.push({ query: { route: slug } })
})
```

Now we just need to remove the other routes from the map. We could do this in the onclick above - but that won't work if we link directly to a specific route (e.g. <a href="https://routes.kevchentw.com/?route=nyckelviken">https://routes.kevchentw.com/?route=nyckelviken</a>). In order to solve this we can add a useEffect instead with the current query as a dependency. Every time the route/query is updated our function will run and update the visible route on the map. The simplest way i found to remove the non-active routes was not to remove the layers but to simply update the layer's visibility to none. In order to get access to our `map` object that's only accessible in the original effect we can save it in a local state variable. 

```jsx

const router = useRouter()
const queryRoute = router.query.route

const [stateMap, setStateMap] = useState(null)

useEffect(() => {
  const map = new mapboxgl.Map({
    container: mapContainer.current,
    style: 'mapbox://styles/mapbox/outdoors-v11',
    center: [lng, lat],
    zoom,
  })
	
	setStateMap(map) // save our map to state to get acces in other useEffects

	return () => map.remove()
}, [])

useEffect(() => {
    if (queryRoute && stateMap) {
      routes.forEach((route: Route) => {
        const { slug } = route
				
		  // Set the current query route as visible
      if (slug === queryRoute) {
        stateMap.setLayoutProperty(slug, 'visibility', 'visible')
        stateMap.setLayoutProperty(`${slug}-fill`, 'visibility', 'visible')

        const coords = route.geoJson.features[0].geometry.coordinates
        const bounds = coords.reduce((b, coord) => {
          return b.extend(coord)
        }, new mapboxgl.LngLatBounds(coords[0], coords[0]))

        // Fit map to bounds/route
        stateMap.fitBounds(bounds, {
          padding: 20,
        })
      } else {
		  // Hide the rest of the routes
          stateMap.setLayoutProperty(slug, 'visibility', 'none')
          stateMap.setLayoutProperty(`${slug}-fill`, 'visibility', 'none')
        }
      })
    } else {
	  // if no selected route then show all routes and restore the zoom to intial bounds
      routes.forEach((route: Route) => {
        const { slug } = route
        if (stateMap) {
          stateMap.setLayoutProperty(slug, 'visibility', 'visible')
          stateMap.setLayoutProperty(`${slug}-fill`, 'visibility', 'visible')
          stateMap.flyTo({
            center: [lng, lat],
            essential: true,
            zoom,
          })
        }
      })
    }
  }, [queryRoute, stateMap])
```

That's it for the map component!

## Styling with Tailwind CSS

To finalise the app I added the list of routes as a sidebar and styled it with [Tailwind CSS](https://tailwindcss.com). When you click a route and the query changes I used Framer Motion to add a slide animation showing a detail view with the meta information. One issue I had was that the original list was often longer than the detail view and when simply moving it to the side it would still take up space and increase the scrollable portion of the page. The solution to this is to add a `transitionEnd` property to our animation setting the element to display none.

```jsx
<motion.div
  animate={
    queryRoute
      ? {
          x: '-30%',
          scale: 0.95,
          transitionEnd: {
            display: 'none', // Completely remove sidebar from the DOM when animation finishes
          },
        }
      : { x: 0, scale: 1, display: 'block' }
  }
  transition={{ ease: 'easeOut', duration: 0.2 }}
>
	// sidebar content
</motion.div>

{queryRoute && (
	<motion.div
	    className="w-full absolute top-0 min-h-screen bg-white -ml-5 -mr-5 px-5"
	    initial={{ x: 430 }}
	    animate={{ x: 0 }}
	    transition={{ ease: 'easeOut', duration: 0.2 }}
	  >
		// detail view content
	</motion.div>
)}
```

## Wrapping up

The last thing I did was create some nice assets, like a favicon and a meta sharing image. Check out <a href="https://routes.kevchentw.com">Trail Routes</a> and let me know if you enjoyed this write-up by pressing like below!

<Image
alt="Trail Routes og image"
caption="Sharing image"
src={'/blog/trailroutes/og.png'}
width={1012}
height={506}
/>


Parallax scrolling has gotten a bad rap, but I believe that's in part because of the very poor implementations out there. As with everything, if we're mindful and make it subtle it can help convey our message more clearly. There's a simple thing you can do to greatly improve the effect: Use a spring-based easing.

Let's take a look at the [Epic React course](https://epicreact.dev) landing page:

<video playsInline autoPlay loop muted width="710" style={{ width: '100%', maxWidth: 710, marginBottom: 20}}>
    <source src="/blog/spring-parallax-framer-motion-guide/epicreact.mp4" type="video/mp4" />
    Sorry, your browser doesn't support embedded videos.
</video>

This is an example of a parallax transition implemented the right way. If you scroll super-quickly you will still see the animation, and if you use a mouse-wheel it never stutters. This is because the animation is eased and not mapped 1:1 to the actual scroll. This way the effect looks super nice! (And most importantly, it makes sense on this landing page and helps deliver the message).

Another website that does this right is [Quill.chat](http://quill.chat), notice how when you scroll through the site you get a sense of joy when the elements smoothly slide into view with just the right velocity. Had they not eased the movement if wouldn't have felt as good.

<video playsInline autoPlay loop muted width="710" style={{ width: '100%', maxWidth: 710, marginBottom: 20}}>
    <source src="/blog/spring-parallax-framer-motion-guide/quill.mp4" type="video/mp4" />
    Sorry, your browser doesn't support embedded videos.
</video>

## I'm convinced - How to implement parallax spring easing with react?

You can implement parallax scrolling in a lot of different ways, for this example I'm using my favourite animation framework Framer Motion to create a reusable `<Parallax />` component. You can do similar things with other frameworks like react-spring or as descibed [here](https://developers.google.com/web/updates/2016/12/performant-parallaxing) by Paul Lewis & Robert Flack on the google developer blog. If you already know the basics of parallax scrolling feel free to skip to the section adding the spring easing.

Let's start by creating a component that accept children as a prop.

```tsx
import { ReactNode } from 'react'

type ParallaxProps = {
  children: ReactNode
}

const Parallax = ({ children }: ParallaxProps): JSX.Element => {
  return children
})

export default Parallax
```

Next up we'll import `useViewportScroll` from framer-motion in order to get how far on the page we have scrolled. We'll use this as the input to another framer-motion hook called `useTransform` in order to calculate our parallax values which we'll add to a `motion.div`.

## Using Framer Motion useTransform

[useTransform](https://www.framer.com/api/motion/motionvalue/#usetransform) takes an input value and a transformer, and outputs a new value. For example:

```tsx
  // The output value will always be double that of `x`.
  const y = useTransform(x, value => value * 2)
```

Lets start by using some random values to see that it's working:

```tsx{2,9-12}
import { ReactNode } from 'react'
import { motion, useViewportScroll, useTransform } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
}

const Parallax = ({ children }: ParallaxProps): JSX.Element => {
  const { scrollY } = useViewportScroll()
  const y = useTransform(scrollY, [100, 200], [0, 500])

  return <motion.div style={{ y }}>{children}</motion.div>
})

export default Parallax
```

In order to find out the correct values we need to add some calculations. The idea is that the component should be centered in it's container when we've scrolled to the middle of the screen, but offset by x pixels when scrolled in either direction.

In order to do this we need two values: what the offsetTop of our element is and the height of the screen. Let's add a ref to our element and use `useLayoutEffect` to save those values when the component is about to mount.

```tsx{1,6,9-12,16-36,39}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  // start animating our element when we've scrolled it into view
  const initial = elementTop - clientHeight
  // end our animation when we've scrolled the offset specified
  const final = elementTop + offset

  const y = useTransform(scrollY, [initial, final], [offset, -offset])

  useLayoutEffect(() => {
    const element = ref.current
    // save our layout measurements in a function in order to trigger
    // it both on mount and on resize
    const onResize = () => {
      // use getBoundingClientRect instead of offsetTop in order to
      // get the offset relative to the viewport
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
})

export default Parallax
```

There's a lot going on here so let's break it down.

<ol>
  <li>We've added an <em>offset</em> prop to specify how strong we want our effect to be.</li>

  <li>We create a ref that we'll use to measure our element</li>

  <li>We setup our state where we'll save elementTop and clientHeight.</li>

  <li>We add a useLayoutEffect where we set those values so we can calculate the start and end for our transformer.</li>

  <li>Finally we put it all together in the useTransform function to get our new <em>y</em> value.</li>
</ol>

## Adding spring easing with useSpring

In order to get the smooth easing we talked about earlier we need to transform our new `y` value with a spring. We can do it with the useSpring hook.

```tsx{2,21-23}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform, useSpring } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  // start animating our element when we've scrolled it into view
  const initial = elementTop - clientHeight
  // end our animation when we've scrolled the offset specified
  const final = elementTop + offset

  const yRange = useTransform(scrollY, [initial, final], [offset, -offset])
  // apply a spring to ease the result
  const y = useSpring(yRange, { stiffness: 400, damping: 90 })

  useLayoutEffect(() => {
    const element = ref.current
    // save our layout measurements in a function in order to trigger
    // it both on mount and on resize
    const onResize = () => {
      // use getBoundingClientRect instead of offsetTop in order to
      // get the offset relative to the viewport
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
})

export default Parallax
```

## Parallax accessibility: useReducedMotion

When designing products with motion we have to be careful and think about people who might have problems viewing things that move around. Some people can get dizzy or nauseous. You can specify this by a setting in you operating system, for example on MacOS the setting is in "Accessibility > Reduce Motion".

Luckily there's a Media Query for this called `prefers-reduced-motion`, and a useful hook exported by framer motion called `useReducedMotion`.

If the user prefers reduced motion we will render the children directly without our parallax container:

```tsx{2,10,34-37}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform, useSpring, useReducedMotion } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const prefersReducedMotion = useReducedMotion()
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  const initial = elementTop - clientHeight
  const final = elementTop + offset

  const yRange = useTransform(scrollY, [initial, final], [offset, -offset])
  const y = useSpring(yRange, { stiffness: 400, damping: 90 })

  useLayoutEffect(() => {
    const element = ref.current
    const onResize = () => {
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  // Don't parallax if the user has "reduced motion" enabled
  if (prefersReducedMotion) {
    return <>{children}</>
  }

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
}

export default Parallax
```

## Wrapping up

Our finished component:

<div style={{ background: 'var(--boxBg)', padding: 100 }}>
  <Parallax>
    <p style={{background: 'var(--brand)', color: 'white', padding: 10, textAlign: 'center', borderRadius: 5, fontWeight: 700}}>Parallax</p>
  </Parallax>
</div>

We've learned how we can create a parallax effect with Framer Motion, improve it by applying a spring easing and taking care of the accesibility aspect with useReducedMotion. Check out the full source code of our Framer Motion example in my [git repo](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/parallax.tsx), and make sure to ❤️ the post below if you liked it, or reach out to me on [twitter](https://twitter.com/samuelkraft) for any comments or questions!





Despite its funny name, If you’ve ever used an iOS device you’ll recognise the [UISegmentedControl](https://developer.apple.com/documentation/uikit/uisegmentedcontrol):

<div style={{ padding: '20px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <video playsInline autoPlay loop muted width="375" style={{ width: '100%', maxWidth: 375, marginBottom: 20}}>
      <source src="/blog/segmented-control-framer-motion/segmented-control-ios-two.mp4" type="video/mp4" />
      Sorry, your browser doesn't support embedded videos.
  </video>
  <video playsInline autoPlay loop muted width="375" style={{ width: '100%', maxWidth: 375}}>
      <source src="/blog/segmented-control-framer-motion/segmented-control-ios-five.mp4" type="video/mp4" />
      Sorry, your browser doesn't support embedded videos.
  </video>
</div>

In this post I’ll show how to recreate it for web using React and Framer Motion resulting in this (try it out by clicking below!):

<div style={{ padding: '80px 7px 50px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <SegmentedControl items={["Upcoming", "Past"]} />
  <br />
  <SegmentedControl items={["H", "D", "W", "M", "Y"]} />
</div>

## Our stack

I’m using a Next.js/React/Typescript/SASS/CSS Modules stack but any react project works fine, as we are use Framer Motion for the animations.

## Our finished component

```tsx
import { useState } from 'react'
import { motion, AnimateSharedLayout } from 'framer-motion'
import styles from './segmentedcontrol.module.scss'

type SegmentedControlProps = {
  items: Array<string>
}

const SegmentedControl = ({ items }: SegmentedControlProps): JSX.Element => {
  const [activeItem, setActiveitem] = useState(0)
  return (
    <AnimateSharedLayout>
      <ol className={styles.list}>
        {items.map((item, i) => {
          const isActive = i === activeItem
          return (
            <motion.li
              className={isActive || i === activeItem - 1 ? styles.itemNoDivider : styles.item}
              whileTap={isActive ? { scale: 0.95 } : { opacity: 0.6 }}
              key={item}
            >
              <button onClick={() => setActiveitem(i)} type="button" className={styles.button}>
                {isActive && <motion.div layoutId="SegmentedControlActive" className={styles.active} />}
                <span className={styles.label}>{item}</span>
              </button>
            </motion.li>
          )
        })}
      </ol>
    </AnimateSharedLayout>
  )
}

export default SegmentedControl
```

```scss
/* CSS variables from my global config */
:root {
  --boxBg: #f3f3f3;
  --activeBg: #292929;
  --text: #000;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

[data-theme='dark'] {
  --boxBg: #1f1e1d;
  --activeBg: #292929;
  --text: #fff;
}
```

```scss
.list {
  display: inline-flex;
  margin: 0;
  padding: 3px;
  list-style: none;
  background-color: var(--boxBg);
  border-radius: 10px;
}

.item {
  position: relative;
  margin-bottom: 0;
  line-height: 1;

  &:after {
    position: absolute;
    top: 15%;
    right: -0.5px;
    display: block;
    width: 1px;
    height: 70%;
    background-color: var(--border);
    transition: opacity 200ms ease-out;
    content: '';
  }

  &:last-of-type {
    &:after {
      display: none;
    }
  }
}

.itemNoDivider {
  composes: item;

  &:after {
    opacity: 0;
  }
}

.button {
  position: relative;
  margin: 0;
  padding: 7px 30px;
  color: var(--text);
  line-height: 1;
  background: transparent;
  border: none;
  outline: none;

  &:hover,
  &:focus {
    cursor: pointer;
  }
}

.label {
  position: relative;
  z-index: 2;
}

.active {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  background-color: var(--inputBg);
  border-radius: 7px;
  box-shadow: var(--shadow);
  content: '';
}
```

There are a few things happening here so let’s walk it through.

First we make sure our component accepts an array of items as props, then we initialise our state to keep track of which item is selected with react `useState`.

```tsx
import { useState } from 'react'

type SegmentedControlProps = {
  items: Array<string>
}

const SegmentedControl = ({ items }: SegmentedControlProps): JSX.Element => {
  const [activeItem, setActiveitem] = useState(0)
  return ()
}

```

<Warning type="info">
In a real-world use case you might opt to keep track of the active item by the page pathname so that you can link to a specific page, in that case you'd get the current pathname with your respective routing solution and then compare it to your items. For Next.js something like:


```tsx
/* example.com/two */

import { useRouter } from 'next/router'

const { pathname } = useRouter()

const items = ['one', 'two', 'three']
{items.map(item => {
  const activeItem = pathname.contains(item)
})}

```
</Warning>

Moving on we wrap our component with `AnimateSharedLayout` from [Framer Motion](https://www.framer.com/motion/), it’s a dead simple way of animating between different elements or components. If you’ve used keynote you can think of it like the “Magic Move” transition. In this example we’re using it to animate our active background state when switching items.

We'll map over our items, get the current active tab by comparing the item index to our state, and for each item return a `motion.li`. [Motion components](https://www.framer.com/api/motion/component/) are used to specify how we want our animation to look like by passing props like `animate` (how the animation will finish), `initial` (our initial state of the animation), `exit` (how our animation looks like when the component dismounts) etc. There are also helper props for things like hover and taps like `whileHover` and `whileTap`. In this example we're using the `whileTap` prop for two things depending on if the item is active or not. If it's active, scale the active state down slightly so the user sees that the UI responds otherwise change the opacity slightly.

If showing more than 2 items, we want to show dividers between the items. We can do this in CSS by using an :after psuedo element. That way we don't need to add any extra elements to the original DOM. Let's change classNames for our motion.li depending on if the divider should be visible or not. There are two scenarios where it should not be visible: 1: when the current item is selected and 2: it's the item before the current selected one. This is because we're positioning the divider to the right of each item (`right: -0.5px`). Our last item does not need any divider so we can remove it with the `:last-of-type` selector. Let's also add an opacity transition so that the dividers fade smootly when switching items.

```tsx
return (
  <AnimateSharedLayout>
    <ol className={styles.list}>
      {items.map((item, i) => {
        const isActive = i === activeItem
        return (
          <motion.li
            className={isActive || i === activeItem - 1 ? styles.itemNoDivider : styles.item}
            whileTap={isActive ? { scale: 0.95 } : { opacity: 0.6 }}
            key={item}
          >
            …
          </motion.li>
        )
      })}
    </ol>
  </AnimateSharedLayout>
)
```
```scss
.item {
  position: relative;
  margin-bottom: 0;
  line-height: 1;

  &:after {
    position: absolute;
    top: 15%;
    right: -0.5px;
    display: block;
    width: 1px;
    height: 70%;
    background-color: var(--border);
    transition: opacity 200ms ease-out;
    content: '';
  }

  &:last-of-type {
    &:after {
      display: none;
    }
  }
}

.itemNoDivider {
  composes: item; /* css modules syntax, compiles to something like "class="item itemNoDivider" */

  &:after {
    opacity: 0;
  }
}
```



We'll add a button inside each item in order to change item on click. If the current item is the active item we add a `motion.div` for rendering the active background styles. This is where we are telling AnimatePresence which element to animate by passing a `layoutId`. It can be any string but needs to match for all elements that should share the same transition. Let's add some styling to the active div and put our item text inside a span in order to position it above the background div with CSS.

```tsx
<button onClick={() => setActiveitem(i)} type="button" className={styles.button}>
  {isActive && <motion.div layoutId="SegmentedControlActive" className={styles.active} />}
  <span className={styles.label}>{item}</span>
</button>
```

```scss
.button {
  position: relative;
  margin: 0;
  padding: 7px 30px;
  color: var(--text);
  line-height: 1;
  background: transparent;
  border: none;
  outline: none;

  &:hover,
  &:focus {
    cursor: pointer;
  }
}

.label {
  position: relative;
  z-index: 2;
}

.active {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  background-color: var(--activeBg);
  border-radius: 7px;
  box-shadow: var(--shadow);
  content: '';
}
```

When clicking to change items our background will now animate magically 🪄. If you try to click the same item that's already active it will scale down slightly. If there are more than 2 items, we'll have dividers between the items that are not siblings to the active one. When switching items the dividers will fade smoothly.

## Our complete component

<div style={{ padding: '80px 7px 50px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <SegmentedControl items={["One", "Two", "Three"]} />
</div>

The full source code is [available on my GitHub](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/segmentedcontrol.tsx).

Creating transitions is super fun with Framer Motion and I am especially excited for the possibilities around AnimatedSharedLayout. It makes it extremely easy to create fluid interfaces and I'll be showing more examples of this in the future!

If this helped press the ❤️ below or let me know on [Twitter](https://twitter.com/samuelkraft)



Click around on this webpage and you'll notice a small transition between each page. In this post I'll show you how to create this page transition using Framer Motion.

## Let's get started

We'll start by installing framer motion

```bash
yarn add framer-motion
```

Then create a new component, PageTransition.tsx to house our transition. We want to animate any children of this component so we'll pass children as a prop.

```tsx
import { ReactNode } from 'react'

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => <div>{children}</div>

export default PageTransition
```

Use this component as a wrapper to any pages you want to animate. In my case I'll add it to my [Page component](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/page.tsx#L29), which sets the layout and shows my footer on all pages.

```tsx{5}
const Page = ({ children }: PageProps): JSX.Element => (
  <div className={styles.container}>
    <Header />
    <main className={styles.main}>
      <PageTransition>{children}</PageTransition>
    </main>
    <Footer />
  </div>
)
```

Framer motion have a couple of different apis to use, and since we want to animate the entry of our children we'll use [AnimatePresence](https://www.framer.com/api/motion/animate-presence/) and [motion components](https://www.framer.com/api/motion/component/). AnimatePresence will animate components when they are added or removed from the React tree. Let's replace our placeholder div with AnimatePresence and nest a motion component that will contain our animation logic.

```tsx
import { ReactNode } from 'react'
import { AnimatePresence, motion } from 'framer-motion'

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => (
  <AnimatePresence>
    <motion.div>
      {children}
    </motion.div>
  </AnimatePresence>
)

export default PageTransition
```

[Motion components](https://www.framer.com/api/motion/component/) are used to specify how we want our animation to look like by passing props like animate (how the animation will finish), initial (our initial state of the animation), exit (how our animation looks like when the component dismounts) etc.

As an example, passing these values we can animate our component from hidden to visible:

```tsx
<motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }} />
```

In our specific case we want to animate the entry of the page as if it was sliding up. We can do this by changing our initial prop's y value, and then resetting it in animate.

```tsx
<motion.div initial={{opacity: 0, y: 8 }} animate={{ opacity: 1, y: 0 }}>
```

Navigate to a different page and our animation is working! However the transition needs some love. Framer motion automatically applies a transition based on what you're animating, as an example if you're just animating opacity it's automatically an easing and in the case of transforms it uses a spring. Let's change our transition by applying our own custom easing function. I recommend [cubic-bezier.com](http://cubic-bezier.com) as a great interactive website where you can create your own easings. We want our transition to start fast and then ease out so let's add a transition property with a duration and our custom easing:

```tsx
<motion.div
  initial={{opacity: 0, y: 8 }}
  animate={{
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    }
  }}
>
```

Now the transition feels a lot better ✌️.

## Improving organisation

We can improve this code further by using framer [variants](https://www.framer.com/api/motion/component/#animationprops.variants), it allows us to keep our animation logic outside out render function in an object organised by name.

Let's create a variable and add our logic. We can name our variants whatever we want, in this case I'll call them 'initial' and 'enter'.

```tsx
const variants = {
  initial: {
    opacity: 0,
    y: 8,
  },
  enter: {
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    },
  },
}
```

In our motion component we'll then pass our variant variable and can then simply reference our variant names in intial & animate:

```tsx
<motion.div initial="initial" animate="enter" variants={variants}>
  {children}
</motion.div>
```

Our complete final example now looks like this:
```tsx
import { ReactNode } from 'react'
import { AnimatePresence, motion } from 'framer-motion'

const variants = {
  initial: {
    opacity: 0,
    y: 8,
  },
  enter: {
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    },
  },
}

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => (
  <AnimatePresence>
    <motion.div initial="initial" animate="enter" variants={variants}>
      {children}
    </motion.div>
  </AnimatePresence>
)

export default PageTransition
```

Feel free to play with transitions and easings, maybe add an exit animation as well? As you've noticed framer motion makes it super easy to create fun and performant transitions. 👌



When deciding to build a website in 2021 there's a bit of a double edged sword, the choices are really endless, with new frameworks and tools getting released almost daily. For this website I wanted to try out [Next.js](https://nextjs.org), a javascript framework built on React that handles all the hard parts about server side rendering & configs. (If you've ever debugged webpack configs you'll appreciate not having to worry about that stuff anymore).

The reason I chose Next.js is how easily you can create really performant websites. With [getStaticProps](https://nextjs.org/docs/basic-features/data-fetching#getstaticprops-static-generation) you can build super fast completely static pages which can also update periodically without needing to rebuild your whole site. In getStaticProps you can call any type of api or fetch data from the filesystem (like this blog), and then forward the data as props to your component. getStaticProps is run at build-time so the visitors will always get served a fast static page.

```js
export async function getStaticProps(context) {
  return {
    props: {}, // will be passed to the page component as props
    // Next.js will attempt to re-generate the page:
    // - When a request comes in
    // - At most once every second
    revalidate: 1, // In seconds
  }
}
```

My initial idea for this website was to have four sections:

- Portfolio
- About me
- Blog
- Book reviews

I knew I wanted to build the blog based on MDX and the Next.js team have a really good [example repo](https://github.com/vercel/next.js/tree/canary/examples/with-mdx-remote) settings this up so I won't go through that part in further detail.

## Fetching data from Notion

Last year I started using [Notion](https://www.notion.so/) and I've grown very fond of it. It's now pretty much my [second brain](https://email.aliabdaal.com/issues/how-to-build-a-second-brain-271393), containing everything from work related things to personal health goals. I read a lot of books which I've just started reviewing and add thoughts to in Notion. It's setup as a simple table containing some pages with reviews. Why not share this on my website?

<Image
  alt="Books section in Notion"
  caption="My books section in Notion"
  src={'/blog/building-my-personal-website-with-nextjs-backed-by-notion/books-table.png'}
  width={1672}
  height={700}
/>

Notion doesn't have a public api ([yet](https://www.notion.so/api-beta)), but we can use an unofficial wrapper called [notion-api-worker](https://github.com/splitbee/notion-api-worker) or roll your own thing like Guillermo Rauch does [here](https://github.com/rauchg/blog/blob/master/lib/notion.js).

<Warning>Note: notion-api-worker uses notion's private api which could change whenever - use at your own risk</Warning>

You can host the api yourself or use the hosted one provided by splitbee like we'll be doing in the example below. Loading our list of books is as simple as creating a new file inside our pages folder, adding getStaticProps and calling the id of our table.

```jsx
export async function getStaticProps() {
  const books = await fetch('https://notion-api.splitbee.io/v1/table/<NOTION_TABLE_ID>').then(res => res.json())

  return {
    props: {
      books,
    },
  }
}
```

<Warning>
  Note: Using their hosted api will only work on published notion pages. Publishing your page on notion will obviously make it public to
  everyone. If you're not ok with keeping non-finished stuff public you can access private pages by adding your NOTION_TOKEN as described{' '}
  <Link href="https://github.com/splitbee/notion-api-worker#authentication-for-private-pages">here</Link>
</Warning>

Our books prop will contain a list of items containing all properties of your subpages. In my example I have a few properties like author, rating, date finished, genres etc.

<Image
  alt="A book in Notion"
  caption="Book properties in Notion"
  src={'/blog/building-my-personal-website-with-nextjs-backed-by-notion/book-properties.png'}
  width={1330}
  height={1052}
/>

Which maps to these types:

```jsx
export type Book = {
    Author: string
    Date: string
    Fiction: boolean
    Genres: Array<string>
    Name: string
    Rating: number
    Published: boolean
    Image: Array<{
        name: string
        rawUrl: string
        url: string
    }>
    Link: string
    id: string
}
```

To render our list of books we'll map over all the books and add some styling:

```jsx
import Link from 'next/link'
import Image from 'next/image'
import Rating from 'components/rating'
import slugifiy from 'slugify'
import styles from './books.module.scss'

<ul className={styles.grid}>
    {books.map(({ Name: title, Author: author, Rating: rating, Image: image, id }) => {
        const slug = slugifiy(title, { lower: true })
            return (
                <li className={styles.book} key={id}>
                    <Link href={books/${slug}}>
                        <a>
                            <Image src={image[0].url} width={218} height={328} className={styles.cover} />
                            <strong className={styles.title}>{title}</strong>
                            <p className={styles.author}>{author}</p>
                            <Rating rating={rating} />
                        </a>
                    </Link>
                </li>
            )
    })}
</ul>
```

We can use Next/Image in order to automatically render an optimised image. When building our specific book pages which will show our reviews and notes I'd like to have pretty slugs instead of using the notion id directly. We can do this either by adding a slug property directly in notion, or use a package like slugify to generate one for us.

For building our book pages we'll use [Next.js dynamic routes](https://nextjs.org/docs/routing/dynamic-routes). We can do this by matching our folder stucture to our url structure. For this example we'll create a "book" folder inside "pages" and create a new file called [slug].js.

```jsx
pages/book/[slug].js → /boom/:slug (/book/vagabonding)
```

Inside [slug].js we need to specify exactly which slugs we have. We do this with the function [getStaticPaths](https://nextjs.org/docs/basic-features/data-fetching#getstaticpaths-static-generation). We'll fetch our books table like before, mapping over the values to create list of possible paths including our custom slugs.

```jsx
export const getStaticPaths: GetStaticPaths = async () => {
    const bookRes = await fetch(https://notion-api.splitbee.io/v1/table/[NOTION_TABLE_ID])
    const bookData = await bookRes.json()
    const paths = bookData.map(b => /books/${slugify(b.Name, { lower: true })})
    return {
        paths,
        fallback: false,
    }
}
```

Moving on to getStaticProps we need to get our list of books again, in order to find out the notion page id for our specific slug. We can get our current page slug from context, which is the first parameter of the function. We'll use it to find the specific book from our list and then fetch that books details by it's id

```jsx
export const getStaticProps: GetStaticProps = async context => {
    const bookRes = await fetch(https://notion-api.splitbee.io/v1/table/[NOTION_TABLE_ID])
    const bookData = await bookRes.json()

    if (!bookData) {
        return {
            notFound: true,
        }
    }

    const { slug } = context.params
    const book = bookData.find(b => slugify(b.name, { lower: true }) === slug)

    const pageRes = await fetch(`https://notion-api.splitbee.io/v1/page/${book.id}
    const pageData = await pageRes.json()

      return {
        props: {
          book,
          page: pageData,
        },
        revalidate: 1,
      }
    }
```

The pageData variable contains json which you can render however you want, or you can simply use the [react-notion](https://github.com/splitbee/react-notion) package created by the same authors as notion-api-worker.

```jsx
import 'react-notion/src/styles.css'
import { NotionRenderer } from 'react-notion'

export default ({ pageData }) => (
  <div style={{ maxWidth: 768 }}>
    <NotionRenderer blockMap={pageData} />
  </div>
)
```

This will in turn render your content pretty much exactly like it appears in Notion. What's really great is that thanks to Next.js static rendering this page will be much faster than notion itself 😅

If you want to tweak the styling simply wrap NotionRenderer in a div and apply any custom styling. On my website I'm using this to tweak a few font-sizes and font-weights and set the text color to a custom variable so my site works in dark mode.

```css
.post {
    h1,
    h2,
    h3,
    h4,
    h5,
    h6,
    p,
    ul,
    li,
    ol {
        color: var(--text);
}
```

That's it, check out an example of this on [/books](/books) and [/books/vagabonding](/books/vagabonding) or the source code available on [GitHub](https://github.com/samuelkraft/samuelkraft-next).

Let me know if you have any questions or feedback by emailing samuelkraft [at] me.com.

✌️
