JSONStore (Socket Supply Module)

Provides simple key-val storage of JSON-compatiable values, backed by the device's filesystem (via Socket Supply's runtime fs module).

This module provides an API that's similar to the browser localStorage API, except that it operates asynchronously (because of the underlying file system operation asynchrony). Other than the use of promises (await, etc), it should be familiar if you've worked with localStorage before.

JSON Serialization/Deserialization

One additional important difference between JSONStore and localStorage: non-primitive (object) values are automatically JSON serialized/de-serialized; the whole data store is serialized to a JSON string, written to a text file (./.store.json).

As such, JSONStore.setItem('customer', { id: 123, name: '..' }) works without needing to first serialize the object value with JSON.stringify(..). Likewise, JSONStore.getItem('customer') will return the already deserialized object, without needing to use JSON.parse(..).

API

getItem(name): returns a promise for the value (if any) in the store that's associated with name property name (string); resolves to undefined if not found

setItem(name, value): sets a value value (JSON-compatible) at the name property in the store; returns a promise, with true on success or false otherwise

removeItem(name): removes the property named name (if any) from the store; returns a promise, with true on success or false otherwise

clear(): removes all entries from the store; returns a promise, with true on success or false otherwise

Usage

import JSONStore from `@socketsupply/json-store`

JSONStore.setItem('zipcode', 78739)     // Promise<true>

JSONStore.getItem('zipcode')   // Promise<78739>

JSONStore.removeItem('zipecode')    // Promise<true>

JSONStore.getItem('zipcode')    // Promise<undefined>

JSONStore.setItem('customer', { id: 123, name: 'Kyle' })    // Promise<true>

JSONStore.getItem('customer')   // Promise<{ id: 123, name: 'Kyle' }>

JSONStore.clear()   // Promise<true>

ESM

This module is provided in ES6-compatible ESM. It exports both a default export of the JSONStore object, as shown above, as well as each API member (setItem(..), getItem(..), etc) as a named export.

License

All code and documentation are (c) 2023 Socket Supply Co and released under the MIT License. A copy of the MIT License is also included.