Angular2 @LocalStorage

This little Angular2/typescript decorator makes it super easy to save and restore automatically a variable state in your directive (class property) using HTML5' LocalStorage.

What's new

Things that have been added in this fork:

• added .save() method on returned object, used in specific cases to force save object changes
• support for Array methods that change its value (push, pop and shift to be exact)
• now WebStorageService.clear() method removes items created by this repository only
• storage key prefix (angular2ws_ by default) can be customized by changing WEBSTORAGE_CONFIG.prefix property

Installation

1. Download the library using npm or github: npm install --save zoomsphere.angular2-localstorage

2. Import the WebStorageModule in your app module:

   import {Component} from 'angular2/core';
   import {WebStorageModule, LocalStorageService} from 'angular2-localstorage';
   
   @NgModule({
       import: [WebStorageModule]
   @Component({
       providers: [LocalStorageService]
   })
   export class AppModule {}

3. If you don't like the default key prefix (angular2ws_) or just don't want to use any, then in your app.module.ts file add the following:

   import {WEBSTORAGE_CONFIG} from 'angular2-localstorage';
   WEBSTORAGE_CONFIG.prefix = ''; // no prefix
   WEBSTORAGE_CONFIG.prefix = 'newPrefix_';

   Note that it's the best to configure this right after installation, because the data saved under keys with previous prefix won't be automatically read anymore - to prevent that you can change keys of already stored data or override them manually.

How to use

1. Use the @LocalStorage() and/or @SessionStorage() decorator functions. Here is where the magic happens, decorated variables' values will be restored from the storage when you reload the site!

   import {LocalStorage, SessionStorage} from 'angular2-localstorage/WebStorage';
      
   class MySuperComponent {
       // it will be stored under ${prefix}viewCounts name
       @LocalStorage() public viewCounts: number = 0;
       // this under name: ${prefix}differentLocalStorageKey
       @LocalStorage('differentLocalStorageKey') protected userName: string = '';
       // and this under ${prefix}itWillBeRemovedAfterBrowserClose in session storage
       @SessionStorage('itWillBeRemovedAfterBrowserClose') private previousUserNames: Array<string> = [];
       
       mySuperMethod(): void {
           this.viewCounts++;
           this.userName = 'some name stored in localstorage';
           this.previousUserNames.push(this.userName);
           for (let userName of this.previousUserNames) {
               // do some stuff
           }
       } 
   }

2. Force save changes. If you need to modify stored object by not a direct assignment, then you can take advantage of .save() method to force save introduced changes. Example:

   import {LocalStorage, SessionStorage, Webstorable} from 'angular2-localstorage';
   
   // this is needed to satisfy Typescript type checking
   type WebstorableObject = Webstorable & Object; // save() method is declared in the Webstorable interface
   type WebstorableArray = Webstorable & Array<any>;
   
   class MySuperComponent {
      @LocalStorage() someObject: WebstorableObject = <WebstorableObject>{};
      @SessionStorage() arrayOfSomethings: WebstorableArray = [0,1,2,3,4];
         
      mySuperMethod() {
          this.someObject.a = 1;
          this.someObject['b'] = 2;
          delete this.someObject['c'];
          for (let something of this.arrayOfSomethings) {
              something++;
          }
          // upper changes won't be saved without the lower line
          this.someObject.save();
          this.arrayOfSomethings.save();
      }
   }

   Alternatively use Local(or Session)StorageService or make straight assignment by hand.

Note: Define always a default value at the property you are using @LocalStorage.

Note: The localstorage key is per default the property name. Define the first argument of @LocalStorage to set different one.

Note: Please don't store circular structures as this library uses JSON.stringify to encode before using LocalStorage.

TODO

• Try to automatically handle all data manipulations using Proxy
• Add tests

Contributions are welcome!