Documentation Pages
Quick Tip #007—Fetch GitHub Stargazers Count (and More) at Build Time
Older iterations of this website used a third party JavaScript widget to show the number of GitHub Stars the project currently had. You can see it in action on the versioned docs for 0.7.1 (scroll to the bottom).
This was in fact the only <script>
tag on the entire 11ty.io web site and it was from a third party. Naturally, it needed to be annihilated.
Let’s change up our architecture to ruthlessly eliminate this client-side JavaScript.
Get the Stargazers Count from the GitHub API #
Read more at the GitHub API documentation.
This is a bit different from our client-side implementation because this data is only as updated as often as your build runs. This is implemented using a global JavaScript data file at _data/github.js
.
- Install new dependencies:
npm install node-fetch --save-dev
- Read more about
node-fetch
const fetch = require("node-fetch");
module.exports = async function() {
console.log( "Fetching new github stargazers count…" );
// GitHub API: https://developer.github.com/v3/repos/#get
return fetch("https://api.github.com/repos/11ty/eleventy")
.then(res => res.json()) // node-fetch option to transform to json
.then(json => {
// prune the data to return only what we want
return {
stargazers: json.stargazers_count
};
});
};
Now in your templates you can output the stargazers count with:
{{ github.stargazers }} GitHub Stars
which outputs
1515 GitHub Stars
Bonus: I created a humanReadableNum
filter) using the human-readable-numbers
package to format the number.
More Examples #
You can look in the footer of this page to see examples of this in use on this very web site. I used it for:
- NPM Download Count
- GitHub Stargazers Count
- Twitter Followers Count (careful here, this one is super brittle but Twitter’s API is historically anti-developer so 😇)
These all use the recommended caching mechanism described in the next section.
Recommended: Cache the Data to the File System #
If I’m working on my site locally, I probably don’t want every Eleventy run to hit this external API call. I’d hit my rate limit pretty quickly (on GitHub, 60 per hour). Instead, let’s use an npm package called flat-cache
to save our results locally to the file system and only run it once per day.
- Install dependencies:
npm install node-fetch flat-cache --save-dev
- Read more about
node-fetch
andflat-cache
.
Highlights: #
- A
_datacache/github-stargazers
file is created that saves the results of the service call. - The data is keyed off the current UTC date.
- If the data already exists in the cache (for the current UTC date), it uses the cached value instead of fetching new data.
const fetch = require("node-fetch");
const flatcache = require("flat-cache");
const path = require("path");
function getCacheKey() {
let date = new Date();
return `${date.getUTCFullYear()}-${date.getUTCMonth() + 1}-${date.getUTCDate()}`;
}
module.exports = async function() {
let cache = flatcache.load("github-stargazers", path.resolve("./_datacache"));
let key = getCacheKey();
let cachedData = cache.getKey(key);
if(!cachedData) {
console.log( "Fetching new github stargazers count…" );
// GitHub API: https://developer.github.com/v3/repos/#get
let newData = await fetch("https://api.github.com/repos/11ty/eleventy")
.then(res => res.json())
.then(json => {
return {
stargazers: json.stargazers_count
};
});
cache.setKey(key, newData);
cache.save();
return newData;
}
return cachedData;
};
If you want to fetch data more frequently than once per day, modify getCacheKey
to return more a specific date. Add an hour to the key to run every hour, for example:
function getCacheKey() {
let date = new Date();
return `${date.getUTCFullYear()}-${date.getUTCMonth() + 1}-${date.getUTCDate()} ${date.getUTCHours()}`;
}
- Current GitHub rate limits are limited to 60 requests per hour, so this will only be a problem if you do more than 60 Netlify builds in an hour.
- The npm API doesn’t seem to have a hard limit.
Update Counts Daily #
If you want to update these counts automatically every day, read Quick Tip #008—Trigger a Netlify Build Every Day with IFTTT.
All Quick Tips
#001
—Inline Minified CSS#002
—Inline Minified JavaScript#003
—Add Edit on GitHub Links to All Pages#004
—Zero Maintenance Tag Pages for your Blog#005
—Super Simple CSS Concatenation#006
—Adding a 404 Not Found Page to your Static Site#007
—Fetch GitHub Stargazers Count (and More) at Build Time#008
—Trigger a Netlify Build Every Day with IFTTT