sifrr-storage ·

Browser key-value(JSON) storage library with cow powers. ~2KB alternative to localForage

Size

| Type | Size | | :----------------------------------------------- | :--------------------------------------------------------: | | Minified (dist/sifrr.storage.min.js) | | | Minified + Gzipped (dist/sifrr.storage.min.js) | |

Types of storages available (in default priority order)

• IndexedDB (Persisted - on page refresh or open/close)
• WebSQL (Persisted - on page refresh or open/close)
• LocalStorage (Persisted - on page refresh or open/close)
• Cookies (Persisted - on page refresh or open/close), Sent to server with every request
• JsonStorage (In memory - deleted on page refresh or open/close)

How to use

Directly in Browser using standalone distribution

Add script tag in your website.

<script src="https://unpkg.com/@sifrr/storage@{version}/dist/sifrr.storage.min.js"></script>
// Adds window.Sifrr.Storage

Browser API support needed

| APIs | caniuse | polyfills | | :----------- | :-------------------------------------------- | :-------------------------------------------- | | Promises API | https://caniuse.com/#feat=promises | https://github.com/stefanpenner/es6-promise | | IndexedDB | https://caniuse.com/#feat=indexeddb | N/A | | WebSQL | https://caniuse.com/#feat=sql-storage | N/A | | LocalStorage | https://caniuse.com/#feat=namevalue-storage | N/A | | Cookies | 100% | N/A |

Using npm

Do npm i @sifrr/storage or yarn add @sifrr/storage or add the package to your package.json file.

example, put in your frontend js module (compatible with webpack/rollup/etc):

Commonjs

const Storage = require('@sifrr/storage');

ES modules

import { getStorage } from '@sifrr/storage';
// or Sifrr.Storage.getStorage (script tag)
// or Storage.getStorage (node js import)

// or
// if you want to use one type of store without support checking based on priority
import { IndexedDB, WebSQL, LocalStorage, Cookies, JsonStorage } from '@sifrr/storage';

API

Sifrr.Storage uses Promises.

Initialization

• Initialize a storage with a type

let storage = getStorage(type);

where type is one of indexeddb, websql, localstorage, cookies, jsonstorage.

Note: If that type is not supported in the browser, then first supported storage will be selected based on priority order.

• Initialize with options

// Options with default values
let options = {
  priority: ['indexeddb', 'websql', 'localstorage', 'cookies', 'jsonstorage'], // Priority Array of type of storages to use
  name: 'SifrrStorage', // name of table (treat this as a variable name, i.e. no Spaces or special characters allowed)
  version: 1, // version number (integer / float / string), 1 is treated same as '1'
  desciption: 'Sifrr Storage', // description (text)
  size: 5 * 1024 * 1024, // Max db size in bytes only for websql (integer)
  ttl: 0 // Time to live/expire for data in table (in ms), 0 = forever, data will expire ttl ms after saving
};
storage = getStorage(options);

Initializing with same priority, name and version will give same instance.

Details

storage.type; // type of storage
storage.name; // name of storage
storage.version; // version number

Setting key-value

// insert single key-value
let key = 'key';
let value = { value: 'value' };
storage.set(key, value).then(() => {
  /* Do something here */
});

// insert multiple key-values
let data = { a: 'b', c: { d: 'e' } };
storage.set(data).then(() => {
  /* Do something here */
});

// inserting with different ttl (30 seconds in example) than set in options
storage.set(key, { value, ttl: 30 * 1000 ).then(() => {
  /* Do something here */
});

Note Cookies are trucated after ~628 characters in chrome (total of key + value characters), other browsers may tructae at other values as well. Use cookies for small data only

Set cookie that can be sent

storage.store = `key=value; expires=...; path=/`;

Getting value

// get single key-value
storage.get('key').then(value => console.log(value)); // > { key: { value: 'value' } }

// get multiple key-values
storage.get(['a', 'c']).then(value => console.log(value)); // > { a: 'b', c: { d: 'e' } }

Deleting a key

// delete single key-value
storage.del('key').then(() => {
  /* Do something here */
});

// delete multiple key-values
storage.del(['a', 'c']).then(() => {
  /* Do something here */
});

Updating a key

.set() will update the value as well.

Get all data in table

storage.all().then(data => console.log(data)); // > { key: { value: 'value' }, a: 'b', c: { d: 'e' } }

Get all keys in table

storage.keys().then(keys => console.log(keys)); // > ['key', 'a', 'c']

Clear table

storage.clear().then(() => {
  // checking if data is deleted
  storage.all().then(data => console.log(data)); // > {}
});

Use for memoization or any function

function some(a, b, c, d) {
  // expensive computation
  return 'a';
}

const memoizedSome = storage.memoize(some); // cache key is unique for unique first function argument

// custom cache key function, should return string
function cacheKeyFunction(a, b, c, d) {
  return JSON.stringify(c);
}
const memoizedSomeCustomCache = storage.memoize(some, cacheKeyFunction);

Get all created storage instances

Sifrr.Storage.all;

Types of data supported

key

should be string

value

can be any of these types:

• Array,
• ArrayBuffer,
• Blob,
• Float32Array,
• Float64Array,
• Int8Array,
• Int16Array,
• Int32Array,
• Number,
• Object,
• Uint8Array,
• Uint16Array,
• Uint32Array,
• Uint8ClampedArray,
• String

Gotchas

• When using localStorage, websql or cookies, binary data will be serialized before being saved (and retrieved). This serialization will incur a size increase when binary data is saved, and might affect performance.
• Since object[key] is undefined when key is not present in the object, undefined is not supported as a value.
• null value has buggy behaviour in localstorage, as it returns null when value is not present.
• If you want to save falsy values, you can save false or 0 which are supported by all storages.