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

$3

Add script tag in your website.

``html

// Adds window.Sifrr.Storage
`

#### Browser API support needed

| APIs | caniuse | polyfills |
| :----------- | :-------------------------------------------- | :-------------------------------------------- |
| Promises API | | |
| IndexedDB | | N/A |
| WebSQL | | N/A |
| LocalStorage | | N/A |
| Cookies | 100% | N/A |

$3

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

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

#### ES modules

`js
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.

$3

- Initialize a storage with a type

`js
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

`js
// 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.

$3

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

$3

`js
// 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

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

$3

`js
// 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' } }
`

$3

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

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

$3

.set() will update the value as well.

$3

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

$3

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

$3

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

$3

`js
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);
`

$3

`js
Sifrr.Storage.all;
`

Types of data supported

$3

should be string

$3

can be any of these types:

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

$3

- 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.