webstorage-decorators/README.md

# WebStorage Decorators
A Javascript library that adds property decorators to sync a class property with the local or session storage.

## Quick Setup
 1. Install with: `npm install --save webstorage-decorators`
 2. Add the decorator to your property and use as normal!
 ```typescript
import {LocalStorage, SessionStorage} from 'webstorage-decorators';
 
export class MyCustomClass {
     @LocalStorage({key: 'site_theme', default: 'light_theme'}) theme: string;
     @SessionStorage({encryptWith: config.entryptionKey}) thisUser: User;
     
     constructor() {
        console.log(this.theme, localStorage.getItem('theme')); // Output: 'light_theme', 'light_theme'
        console.log(this.user, localStorage.getItem('user')); // Output: null, undefined
        user = {first: 'John', last: 'Smith', ...}
        console.log(this.user, this.user == localStorage.getItem('user')); // Output: {first: 'John', last: 'Smith', ...}, true
    }
}
 ```

## Caveats

### Custom Functions
You can technically store anything inside local/session storage however everything is serialized using javascript's JSON,
so any prototypes will be stripped causing you to lose any extra functions you may have defined on your class. However
if you provide a default value, 

### Impure Functions
Impure functions don't use the Object's setter preventing the storage from being updated. To prevent this use a pure
function or save it manually by reading the variable. (Reading triggers change detection & save if there are differences)
```typescript
@LocalStorage([1, 2]) example: number[];
example.push(3) // Impure & won't update storage
console.log(localStorage.getItem('example')) // Output: [1, 2];
example; // Trigger save
console.log(localStorage.getItem('example')) // Output: [1, 2, 3];

// OR

example = example.concat([3]); // Pure function requires you to use the setter triggering automatic saving
```