@flk/session

Cache

The cache system is built on LocaleStorage API.

Installation

flk install flk-cache

OR

npm install flk-cache

Alias: cache.

Table of contents

• Cache
• Installation
• Table of contents
• Usage
• Available methods
  • Set
    • Examples
  • Get
    • Examples
  • Has
    • Examples
  • Remove
    • Examples
  • Clear
    • Examples
• Configurations
• Constants

Usage

Once you resolve the cache object you can use the methods below.

class HomePage {
    /**
     * {@inheritDoc}
     */
    constructor(cache) {
        this.cache = cache;
    } 
}

Available methods

• set
• get
• has
• remove
• clear

Set

set(key: String, value: any, expiresAt: Number = Cache.FOREVER): Self

This method accepts any type of values, the cache engine will handle it automatically, so if you want to store object, you don't have to JSON.stringify it, the package will take care of it.

The expiresAt parameter is used to determine until when the value should be stored in.

Please note that this method accepts a valid timestamp number, i.e Date.now().

The default value for expiresAt is set to Cache.FOREVER which mean the value will not be removed from the cache until the user clears the browser history.

There are some useful constants for cache expiration time.

Examples

let cache = DI.resolve('cache');

cache.set('name', 'Hasan');

// It can also store objects
let user = {
    name: 'Hasan',
    address: 'Some street address',
};

cache.set('user', user);

// storing arrays is acceptable as well
let users = [{
    name: 'Hasan',
    address: 'Some street address',
}, {
    name: 'John Doe',
    address: 'Another address',
}];

cache.set('users', users);

// cache for one hour
cache.set('accessToken', MyAccessToken, Cache.FOR_ONE_HOUR);11

Get

get(key: String, defaultValue: any = null): any|null

Retrieve value from cache.

If the key doesn't exist, defaultValue will be returned instead.

Examples

let cache = DI.resolve('cache');

// if the given key exists
let name = cache.get('name'); // Hasan

// if the given key doesn't exists, return null
let age = cache.get('age'); // null

// if the given key doesn't exists, return the given default value instead.
let email = cache.get('email', '[e-mail]'); // [e-mail]

Has

has(key: String): Boolean

Determine if the given key exists in cache.

Examples

let cache = DI.resolve('cache');

if (cache.has('name')) {
    // do something
}

Remove

remove(key: String): void

Remove the given key if exists in cache storage.

Examples

let cache = DI.resolve('cache');

cache.remove('name');

Clear

clear(): void

Clear all cache values.

Examples

let cache = DI.resolve('cache');

cache.clear();

Configurations

Available configurations for cache in Application configurations.

Main Configuration key: cache

key	Type	Default value	Description
encryptValues	Boolean	true	If set to true, any value will be encrypted using the Crypto package.

It's recommended to set the type of the encryptionValue in your config.js in the beginning of your application development as it works on all the cached values.

Constants

constant	Description
Cache.FOR_ONE_HOUR	Cache the value for one hour.
Cache.FOR_TWO_HOURS	Cache the value for two hours.
Cache.FOR_ONE_DAY	Cache the value for one day.
Cache.FOR_ONE_WEEK	Cache the value for one week.
Cache.FOR_ONE_MONTH	Cache the value for one month.
Cache.FOR_ONE_YEAR	Cache the value for one year.
Cache.FOREVER	Cache the value until the visitor clears the browser history.