Session Storage Utilities

Convenient utilities to safely interact with the browser's Session Storage API. Store, retrieve, and remove typed items for per-tab and per-session persistence.

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Import

import {
  getFromSessionStorage,
  saveToSessionStorage,
  removeFromSessionStorage,
} from 'nhb-toolbox';

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getFromSessionStorage

Type-safe getter for items stored in session storage.

function getFromSessionStorage<T>(key: string): T | null

Usage Examples

String Value

// Given: sessionStorage.setItem('color', JSON.stringify('blue'))
const color = getFromSessionStorage<string>('color');
// Returns: 'blue'

Object Value

// Given: sessionStorage.setItem('cart', JSON.stringify({ total: 30, items: 4 }))
const cart = getFromSessionStorage<{ total: number; items: number }>('cart');
// Returns: { total: 30, items: 4 }

Nonexistent Key

const missing = getFromSessionStorage<string>('notfound');
// Returns: null

Parameters

Name	Type	Description
key	string	The key for the session storage item.

Returns

• The parsed value (T) if it exists and can be parsed from JSON.
• null if the key does not exist.

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saveToSessionStorage

Stores values in session storage as JSON.

function saveToSessionStorage<T>(key: string, value: T): void

Usage Examples

Primitive/Number

saveToSessionStorage('count', 10);
// sessionStorage entry: { count: "10" }

Object

saveToSessionStorage('profile', {
  id: 7,
  username: 'user7',
  online: true
});
// sessionStorage entry: { profile: '{"id":7,"username":"user7","online":true}' }

Parameters

Name	Type	Description
key	string	The key under which to store the value.
value	T	The value to store (any JSON-safe type).

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removeFromSessionStorage

Removes an item from session storage.

function removeFromSessionStorage(key: string): void

Usage Example

removeFromSessionStorage('cart');
// Removes 'cart' from session storage. No effect if not found.

Parameters

Name	Type	Description
key	string	The key to remove from session storage.

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Key Features

1. Type Safety: You get the right type back, thanks to generic inference.
2. Consistent JSON Handling: Storage is always as stringified JSON.
3. Per-Tab Session: Data is unique per browser tab or window session.
4. Simple and Fast: Easy, one-liner API for all value types.

Limitations

1. JSON Only: Only serializable values are supported.
2. Session Scope: Data persists only until the tab or window is closed.
3. No Expiry: No built-in expiration or time-to-live.
4. Browser Only: Not available server-side, and may be disabled in some contexts (incognito, etc).
5. No Error Catching: No handling of quota issues or deserialization errors.

Notes

• Use for temporary state, like wizard steps, auth, or UI state per tab.
• Keys not found return null, distinguishing from undefined or other falsey values.
• Clear session storage for security-sensitive data on logout or navigation.

Recommended Use Cases

• Storing tab-specific state (temporary settings, form progress, etc.).
• Multi-step workflows, wizard data, cart/session caching.
• UI state, selections, or navigation history per session/tab.

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Conclusion:
These utilities make working with session storage type-safe, reliable, and convenient—perfect for browser apps needing quick tab/session-scoped persistence.