Caching

Question 1

Where do you need to implement a contract to create a custom cache driver?

Answer 1

Illuminate\Contracts\Cache\Store

Question 2

Given a fully set up custom cache driver, how do you call upon it?

Answer 2

Cache::extend('NAME FOR THIS CACHE', function (Application $app) {
    return Cache::repository(new NAME OF CACHE DRIVER);
});

Question 3

How can you register a new cache driver?

Answer 3

To register the custom cache driver with Laravel, we will use the extend method on the Cache facade. Since other service providers may attempt to read cached values within their boot method, we will register our custom driver within a booting callback. By using the booting callback, we can ensure that the custom driver is registered just before the boot method is called on our application’s service providers but after the register method is called on all of the service providers. We will register our booting callback within the register method of our application’s App\Providers\AppServiceProvider class:

public function register(): void
{
    $this->app->booting(function () {
         Cache::extend('mongo', function (Application $app) {
             return Cache::repository(new MongoStore);
         });
     });
}

Question 4

Which environmental variable do you need to update after registering your extension?

Answer 4

CACHE_STORE

Question 5

What is the default cache driver used by Laravel called?

Answer 5

database

Question 6

If your application does not contain the database migration, how can you create it using Artisan?

Answer 6

php artisan make:cache-table
php artisan migrate

Question 7

What gets returned, if you attempt to use the Cache facade’s get method for an item, that does not exist in the cache?

Answer 7

null

Question 8

Define a variable $value using the cached items “key” and “default”!

Answer 8

$value = Cache::get('key', 'default');

Question 9

You don’t always want the default values of variables to be retrieved when an item does not exist in cache. How can you pass a closure as the default value?

Answer 9

$value = Cache::get('NAME OF ITEM', function () {
    return DB::table(/* ... */)->get();
});

Question 10

Which method can you use to see if an item exists in cache?

Answer 10

Cache::has('NAME OF ITEM')

Question 11

What will Cache::has(‘example’) return, if the item exists, but has the value “null”?

Answer 11

false

Question 12

How can you put an item into cache? Specify the amount of time that it should be cached for as 10 minutes!

Answer 12

Cache::put('example', 'value', now()->addMinutes(10));

Question 13

Retrieve the value “example” as $value from the cache, if it isn’t cached yet retrieve from the database and cache it for $seconds!

Answer 13

$value = Cache::remember('example', $seconds, function () {
    return DB::table('example')->get();
});

Question 14

How can you Cache a retrieved item for an unlimited amount of time?

Answer 14

Cache::rememberForever('example', function() {
    return DB::table('example')->get();
});

Question 15

Retrieve “example” as $value from cache and then delete the item!

Answer 15

$value = Cache::pull('example');

Question 16

How do you put items into cache indefinitely?

Answer 16

Cache::put('example', 'value');

By not specifying an amount of time, it will be cached forever

Question 17

What do you need to do to only add an item into cache, if the item is not cached already?

Answer 17

Cache::add('example', 'value', $seconds);

Question 18

What will Cache::add return, if the value was successfully cached?

Answer 18

true

Question 19

What will Cache::add return, if the value already existed in cache?

Answer 19

false

Question 20

How can you add something to cache forever?

Answer 20

Cache::forever('example', 'value');

Question 21

Remove an item from cache!

Answer 21

Cache::forget('example');

Question 22

Remove items from cache using the put method!

Answer 22

Cache::put('example', 'value', -5);

Question 23

Clear the entire cache!

Answer 23

Cache::flush();

Flushing the cache does not respect your configured cache “prefix” and will remove all entries from the cache. Consider this carefully when clearing a cache which is shared by other applications.

Question 24

Store a value in cache using the global cache function!

Answer 24

$value = cache('example');

Question 25

Add 2 values to cache for 10 minutes using the global cache function!

Answer 25

cache(['example' => 'value'], now()->addMinutes(10));

Question 26

How can you call other caching methods in the global cache function?

Answer 26

cache()->
enter the other method after the ->