How to cache facebook graph api call - php

Question

I've created a function to get the likes for my facebook page using the graph api. However, the level rate limit keeps on getting reached as it's being called on every request.
How would i cache this so it doesn't make the call every time?
The code i'm currently using is:
function fb_like_count() {
$id = '389320241533001';
$access_token = 'access token goes here';
$json_url ='https://graph.facebook.com/v3.2/'.$id.'?fields=fan_count&access_token='.$access_token;
$json = file_get_contents($json_url);
$json_output = json_decode($json);
if($json_output->fan_count) {
return like_count_format($json_output->fan_count);
} else{
return 0;
}
}

Answer 1

There are many cache mechanism in PHP that you can use depending on your project size.
I would suggest you to check memcached or Redis. These are in-memory cache mechanisms that are pretty fast and would help you to gain better performance.
You can read more about how to implement memcached here or for redis here.
The second and easier way is to use file caching. It works like this:
You send a request to Facebook API and when response is returned you save it to a file. When you want to send the second response you can check if there is any content in your file first and if there is you can return that directly to your application otherwise you will send the request to Facebook API
Simple integration is like this
if (file_exists($facebook_cache_file) && (filemtime($facebook_cache_file) > (time() - 60 * 15 ))) {
// Cache file is less than 15 minutes old but you can change this.
$file = file_get_contents($facebook_cache_file); // this holds the api data
} else {
// Our cache is out-of-date, so load the data from our remote server,
// and also save it over our cache for next time.
$response = getFacebookData() // get data from facebook and save into file
file_put_contents($facebook_cache_file, $response, LOCK_EX);
}
Anyway I would suggest you to use any PHP library for doing file cache.
Below you can find some that might be interesting to look at:
https://github.com/PHPSocialNetwork/phpfastcache
https://symfony.com/doc/current/components/cache.html