Persistence

This service provides simple persistence drivers that implement a common PersistenceDriver interface. It is used by BaseForm, but can also be used directly.

Available Drivers

• NonPersistentDriver — no persistence (default for BaseForm)
• MemoryPersistenceDriver — keeps data in memory, useful for tests and non-browser environments
• SessionStorageDriver — uses sessionStorage
• LocalStorageDriver — uses localStorage

All drivers are exported from @blueprint-ts/core/persistenceDrivers.

Using A Driver

import { MemoryPersistenceDriver } from '@blueprint-ts/core/persistenceDrivers'

const driver = new MemoryPersistenceDriver('optional-suffix')

driver.set('my-key', { value: 123 })
const value = driver.get<{ value: number }>('my-key')

Multiple MemoryPersistenceDriver instances share the same in-memory store when they use the same suffix and key. This makes it convenient for tests where one instance writes persisted state and another instance asserts it later.

If you need to reset the in-memory store between tests:

MemoryPersistenceDriver.clear()

Implementing A Custom Driver

Implement the PersistenceDriver interface:

import { type PersistenceDriver } from '@blueprint-ts/core/persistenceDrivers'

export class MemoryDriver implements PersistenceDriver {
  private store = new Map<string, unknown>()

  get<T>(key: string): T | null {
    return (this.store.get(key) as T) ?? null
  }

  set<T>(key: string, state: T): void {
    this.store.set(key, state)
  }

  remove(key: string): void {
    this.store.delete(key)
  }
}