# sifrr-storage ยท [](https://www.npmjs.com/package/@sifrr/storage) [](https://sifrr.github.io/sifrr/#/./packages/browser/sifrr-storage/)
Browser key-value(JSON) storage library with cow powers. ~2KB alternative to [localForage](https://github.com/localForage/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.
```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 |
### 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
```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.
### Initialization
- 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.**
### Details
```js
storage.type; // type of storage
storage.name; // name of storage
storage.version; // version number
```
### Setting key-value
```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=/`;
```
### Getting value
```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' } }
```
### Deleting a key
```js
// 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
```js
storage.all().then(data => console.log(data)); // > { key: { value: 'value' }, a: 'b', c: { d: 'e' } }
```
### Get all keys in table
```js
storage.keys().then(keys => console.log(keys)); // > ['key', 'a', 'c']
```
### Clear table
```js
storage.clear().then(() => {
// checking if data is deleted
storage.all().then(data => console.log(data)); // > {}
});
```
### Use for memoization or any function
```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);
```
### Get all created storage instances
```js
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.