Live example in Angular 🎥

Browser Storage Utilities ⚒️

🔥 StorageUtilities is a front-end library that provides handy methods to facilitate CRUD operations to data stored in the browser. It also allows global/class level settings to easily, and consistently, manage the state of the stored data.

StorageUtilities provides optional expiry/TTL (Time To Live) functionality to allow temporary data storage. It also allows subscribers to be notified of any state changes to stored data.

The internal implementation relys on the web storage objects localStorage and sessionStorage, as well as the methods they provide setItem/getItem/removeItem/clear

✏️ Key Goals

• Simplify CRUD operations to stored data in localStorage & sessionStorage
• Allow global/class level settings for consistency
• Support expiry/TTL (Time To Live) feature
• Provide state change notifications to subscribers
• Can be easily used in any front-end JavaScript codebase application

⬇️ Installation

npm install browser-storage-utilities --save

Usage 💡

TypeScript

import { StorageUtilities } from 'browser-storage-utilities';

export class UserStorageService extends StorageUtilities <User> {
    ...

    constructor() {
        super({ /* global settings (optional) */ });
    }

}

The settings interface 🏁

export interface IStorageSettings {
    keyPrefix? : string; // prefixes all items' keys prior to being stored, e.g. 'user-'
    type? : StorageTypes; // localStorage (default) / sessionStorage
    setExpiryMilliseconds? : number; // time to live (TTL), e.g. 5000ms
    setReturnType? : StorageReturnTypes; // the item(s) to be returned as a Promise or Observable
    notifiedOfStateChanges? : boolean; // for subscriber(s) to be notified of any storage state changes
}

Note: 💡 Some of these settings (type, setExpiryMilliseconds, and setReturnType) can be applied per method as well, which always take precedence over global settings:

// set globally
...
constructor() {
   super({ keyPrefix: 'user-', setExpiryMilliseconds: 5000, notifiedOfStateChanges: true, setReturnType: StorageReturnTypes.Promise, type: StorageTypes.SESSION });
...

// set per method
this.userStorageService.addUser('123', user, 5000, StorageTypes.SESSION);

// return item
const storedUser = this.userStorageService.getUser('123', StorageTypes.SESSION);
console.log('storedUser: ', storedUser); // user data

// return item as a Promise
const storedUserPromise = this.userStorageService.getUser('123', StorageTypes.SESSION, StorageReturnTypes.Promise);

storedUserPromise.then(user => {
  console.log('user: ', user); //user data
})

Default settings 📌

export const defaultSettings: IStorageSettings = {
    keyPrefix: '',
    type: StorageTypes.LOCAL // set to localStorage by default
};

Example 🚀

import { StorageUtilities, StorageTypes } from 'browser-storage-utilities';

export class UserStorageService extends StorageUtilities <User> {

    constructor() {
        super({ keyPrefix: 'user-', notifiedOfStateChanges: true, type: StorageTypes.SESSION });
    }

    addUser(id: string, user: User, expiry? : number, storageType? : StorageTypes): void {
        this.addItem(id, user, expiry, storageType);
    }

    getUser(id: string, storageType? : StorageTypes): User {
        return this.getItem(id, storageType);
    }

    updateUserProperty(id: string, propName: string, newValue: any, storageType ? : StorageTypes): User {
        return this.updateItemProperty(id, propName, newValue, storageType);
    }

    removeUserProperty(id: string, propName: string, storageType? : StorageTypes): User {
        return this.updateItemProperty(id, propName, newValue, storageType);
    }

    removeUser(id: string, storageType? : StorageTypes): void {
        this.removeItem(id, storageType);
    }

    removeUsers(ids: string[], storageType? : StorageTypes): void {
        this.removeItems(ids, storageType);
    }

}

Subscribe to storage state changes 🎯

import { IStorageNotifier } from 'browser-storage-utilities';

...

this.userStorageService.storageStateChanged.subscribe((userData: IStorageNotifier <User> ) => {
    if (userData) {
        console.log('storage: ', userData.storage); // localStorage or sessionStorage
        console.log('oldValue: ', userData.oldValue); // previous data
        console.log('newValue: ', userData.newValue); // current data
    }
});

Store data with a 5 second expiry (TTL) ⏳

...

this.userStorageService.addUser('123', user, 5000);
/* 
localStorage: {
  expiry: 1590853867699,
  value: {
    id: '123',
    firstName: 'John',
    lastName: 'Doe',
    ...
  }
}
*/

// if expiry time has elapsed, item is removed from storage, and null will be returned.
const storedUser = this.userStorageService.getUser('123');

console.log('storedUser: ', storedUser); // null

📄 Settings API

Methods	Description
static get defaultSettings(): IStorageSettings	Returns default settings applied to StorageUtilities
static get currentSettings(): IStorageSettings	Returns current settings applied to StorageUtilities
static set customSettings(settings: IStorageSettings)	Sets custom settings to be applied to StorageUtilities. They will always overwrite default settings
static resetSettings(): void	Resets to default settings applied to StorageUtilities

📄 Core methods API

Methods	Description
addItem(key: string, item: T, expiry?: number, storageType?: StorageTypes): void	Adds the item to Storage with its key. The item is added to localStorage by default, or sessionStorage if specified by @param storageType. The item can be added with an expiry time (in milliseconds). This is to add a TTL (Time to live) to invalidate item after the expiry time elapses.
getItem(key: string, storageType?: StorageTypes, returnType?: StorageReturnTypes): T	Returns the item stored in Storage by its key. If item is not found, or it has an expiry time which has elapsed, null will be returned. The item can be returned as a Promise or Observable if @param returnType is specified. The item is returned from localStorage by default, or sessionStorage as specified by @param storageType.
updateItemProperty(key: string, propName: string, newValue: any, storageType?: StorageTypes): T	Updates the value of a specific property for the stored item. The property can be of any type. If the property doesn't exist, a new property will be created. If the item is not found by key, or has expired, null will be returned, or updated item will be returned otherwise.
removeItemProperty(key: string, propName: string, storageType?: StorageTypes): T	Removes the item's specified property. If the item is not found by key, or has expired, null will be returned, or updated item will be returned otherwise.
removeItem(key: string, storageType?: StorageTypes): void	Removes item from Storage by its key. The item is removed from localStorage by default, or sessionStorage if specified by @param storageType.
removeItems(keys: string[], storageType?: StorageTypes): void	Removes items from Storage by their keys. The items are removed from localStorage by default, or sessionStorage if specified by @param storageType.
clearStorage(storageType?: StorageTypes): void	Removes all items from storage. The items are removed from localStorage by default, or sessionStorage if specified by @param storageType.

📄 Additional methods API

Methods	Description
getStorageState(): Observable<IStorageNotifier<T>>	Returns storage state as an Observable of type IStorageNotifier<T>. All subscribers will be notified when state changes.
getStorageItems(storageType?: StorageTypes, returnType?: StorageReturnTypes): StorageItem<T>[]	Returns an Array of all storage items. The items are returned from localStorage by default, or sessionStorage if specified by @param storageType. The items can be returned as a Promise or Observable if @param returnType is specified.
getStorageValues(storageType?: StorageTypes, returnType?: StorageReturnTypes): T[]	Returns an Array of all storage values. The values are returned from localStorage by default, or sessionStorage if specified by @param storageType. The values can be returned as a Promise or Observable if @param returnType is specified.
getStorageKeys(storageType?: StorageTypes, returnType?: StorageReturnTypes): string[]	Returns an Array of all storage keys. The keys are returned from localStorage by default, or sessionStorage if specified by @param storageType. The keys can be returned as a Promise or Observable if @param returnType is specified.

Author 📚

Ahmed Alatawi