Light-storage NPM

light-storage

A lightweight tool for handing localStorage.

Serialization and deserialization
Using prefix to avoid key collisions
Support expiration
Support call chaining
Observer Pattern
100% test coverage

Install

NPM

npm install --save light-storage
# or
yarn add light-storage

import LightStorage from 'light-storage';

CDN

<script src="https://cdn.jsdelivr.net/npm/light-storage@1/dist/light-storage.umd.min.js"></script>

Basic Usage

Get instance

// generate an instance with prefix
const storage = new LightStorage('PREFIX');

Set data

Set the value with the given key, creating a new value if none existed.
```
storage.set('key', 'example');
```

Set the value that expires 2 minutes from now.

storage.set('key', 'example', { maxAge: 2 * 60 * 1000 });

If you need to time again, set update to true.

storage.set('key', 'example', { maxAge: 2 * 60 * 1000, update: true });

Using call chaining.

storage
  .select('key')
  .setValue('example')
  .setMaxAge(2 * 60 * 1000);

// if need to update creation time
storage.select('key').update();

Get data
Note: return undefined if none existed
- Get the current value associated with the given key.
```
storage.get('key');
```
- Using call chaining.
```
storage.select('key').value;
```
Delete data
- Remove the data with the given key.
```
storage.remove('key');
```
- Using call chaining.
```
storage.select('key').remove();
```
- Clear all.
```
storage.clear();
```
Watch
Note: since v1.1.0, based on @xunmi/event-channel.
Warning: can't watch if you use native operations (e.g. localStorage.setItem).
- Watch the change of a value associated with the given key.
```
const observer = (value, oldValue) => {
  // do something
};

storage.watch('key', observer);
```
- Unwatch that stops firing the observer.
```
storage.unwatch('key', observer);
```
- Using call chaining.
```
// watch
storage.select('key').watch(observer);

// unwatch
storage.select('key').unwatch(observer);
```

Other Usage

Get all keys.
```
storage.keys;
```
Set a new prefix to replace the original prefix.
```
storage.prefix = 'NEW_PREFIX';
```

Get other metadata associated with the given key.

// return the created time
storage.getCreatedTime('key');
// return the `maxAge`
storage.getMaxAge('key');
// whether it contains the key
storage.has('key');

Synchronize data in the localStorage, and check validity.
Note: If you use localstorage directly and things don't work as expected, you may need to use this function.
```
storage.reload();
```