# 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 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 ```