@oleksii-pavlov/storages - List of Utilities for LocalStorage, SessionStorage, and Caching

Installation

npm install @oleksii-pavlov/storages

Classes

LocalStorage<Value>

Manages values in localStorage.

• Constructor:
  • (key: string, defaultValue: Value | null = null)
• Methods:
  • getValue(): Value | null
  • setValue(value: Value): void
  • removeValue(): Value | null

SessionStorage<Value>

Manages values in sessionStorage.

• Constructor:
  • (key: string, defaultValue: Value | null = null)
• Methods:
  • getValue(): Value | null
  • setValue(value: Value): void
  • removeValue(): Value | null

CacheStorage<Value>

Implements a caching mechanism with timeout support.

• Constructor:
  • (storage: Storage<CachedValue<Value>>, timeout: number, defaultValue?: Value | null)
• Properties:
  • readonly defaultValue: Value | null
• Methods:
  • getValue(): Value | null
  • setValue(value: Value): void
  • removeValue(): Value | null

CollectionStorage<Value>

Manages collections of values and allows retrieving or removing them by a selector.

• Constructor:
  • (storage: Storage<Value[]>, defaultValue?: Value | null)
• Methods:
  • getValueBySelector(selector: Selector<Value>): Value | null
  • setValue(value: Value): void
  • removeValueBySelector(selector: Selector<Value>): void
  • removeAllValues(): void

HashMapStorage<Value>

Manages a dictionary-like structure of values.

• Constructor:
  • (storage: Storage<HashMap<Value>>, defaultValue?: Value | null)
• Methods:
  • getValueByKey(key: HashMapKey): Value | null
  • setValueByKey(key: HashMapKey, value: Value): void
  • removeValueByKey(key: HashMapKey): void
  • removeAllValues(): void

Interfaces and Types

Storage<T>

Defines a general interface for storage classes.

• Properties:
  • readonly defaultValue: T | null: The default value returned when no value exists in storage.
• Methods:
  • getValue(): T | null: Retrieves the value from storage.
  • setValue(value: T): void: Saves a value to storage.
  • removeValue(): T | null: Removes the value from storage and returns it.

CachedValue<T>

Represents a cached value with metadata.

• Properties:
  • value: T: The cached value.
  • saveMoment: number: The timestamp when the value was cached.

Selector<Value>

Defines a function type used to select specific values from collections.

• Signature: (value: Value, index: number, array: Value[]) => boolean

HashMap<T>

Represents a dictionary-like structure where keys are strings or numbers.

• Extends: Record<HashMapKey, T>

HashMapKey

Defines valid keys for a HashMap.

• Type: string | number

Example Usages

Setups Overview

The concept of setups provides predefined configurations and wrappers for specific storage use cases, such as managing collections, hash maps, or cached data. These setups streamline implementation by encapsulating the Storage logic with a higher-level API, allowing for easy instantiation and reuse across local and session storages. Below, examples showcase how setups simplify the usage of storage classes. The main purpose of setups is to reduce boilerplate code amount leaving only straightforward parts. Setups are defined for all wrappers for both local and session storage. They are named as <Wrapper><Local/Session>Storage. For example, CacheLocalStorage is a cache storage with local storage approach.

LocalStorage with Setup Example

import { CollectionLocalStorage } from '@oleksii-pavlov/storages'

const productStorage = new CollectionLocalStorage<Product>('products', null)

productStorage.setValue({ id: 1, name: 'Laptop', category: 'Electronics', price: 1500 })
productStorage.setValue({ id: 2, name: 'Chair', category: 'Furniture', price: 100 })

const laptop = productStorage.getValueBySelector(product => product.name === 'Laptop')
console.log(laptop) // { id: 1, name: 'Laptop', category: 'Electronics', price: 1500 }

CacheStorage with Setup Example

import { CacheLocalStorage } from '@oleksii-pavlov/storages'

const userCache = new CacheLocalStorage<string>('userCache', 60000, 'defaultUser')
userCache.setValue('cachedUser')
console.log(userCache.getValue())

LocalStorage Example

const localStorageManager = new LocalStorage<number>('exampleKey', 42)

localStorageManager.setValue(100)
console.log(localStorageManager.getValue()) // 100

localStorageManager.removeValue()

CacheStorage Example

const localStorageForCache = new LocalStorage<CachedValue<string>>('cacheKey')
const cache = new CacheStorage(localStorageForCache, 60000, 'defaultCacheValue') // 1-minute timeout

cache.setValue('cachedValue')
console.log(cache.getValue())

CollectionStorage Example

interface Product {
  id: number
  name: string
  category: string
  price: number
}

const productStorage = new LocalStorage<Product[]>('products', [])
const productCache = new CollectionStorage(productStorage, null)

// Add new products
productCache.setValue({ id: 1, name: 'Laptop', category: 'Electronics', price: 1500 })
productCache.setValue({ id: 2, name: 'Chair', category: 'Furniture', price: 100 })
productCache.setValue({ id: 3, name: 'Headphones', category: 'Electronics', price: 200 })

// Get a product by selector
const laptop = productCache.getValueBySelector(product => product.name === 'Laptop')
console.log(laptop) // { id: 1, name: 'Laptop', category: 'Electronics', price: 1500 }

// Remove a product by selector
productCache.removeValueBySelector(product => product.id === 2)

// Get all remaining products
const allProducts = productStorage.getValue()
console.log(allProducts)
// [
//   { id: 1, name: 'Laptop', category: 'Electronics', price: 1500 },
//   { id: 3, name: 'Headphones', category: 'Electronics', price: 200 }
// ]

// Remove all products
productCache.removeAllValues()
console.log(productStorage.getValue()) // []

HashMapStorage Example

const hashMapStorage = new LocalStorage<HashMap<string>>('hashMapKey', {})
const hashMap = new HashMapStorage(hashMapStorage, 'defaultHashValue')

hashMap.setValueByKey('key1', 'value1')
console.log(hashMap.getValueByKey('key1')) // 'value1'

hashMap.removeValueByKey('key1')