ImmortalDB is the best way to store persistent key-value data in the browser. Data saved to ImmortalDB is redundantly stored in Cookies, IndexedDB, and LocalStorage, and relentlessly self heals if any data therein is deleted or corrupted.
For example, clearing cookies is a common user action, even for non-technical users. And browsers unceremoniously delete IndexedDB, LocalStorage, and/or SessionStorage without warning under storage pressure.
ImmortalDB is resilient in the face of such events.
In this way, ImmortalDB is like Evercookie, but
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Is actively maintained and well documented.
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Provides a simple, modern, Promise-based API.
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Strikes an equitable balance between reliability and respect for the user. Data is stored reliably but can also be voluntarily purged if the user designedly clears cookies and application storage.
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Doesn't use nefarious exploits nor deprecated third party plugins like Flash, Silverlight, or Java. Only standard, ratified HTML5 APIs are used.
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Doesn't vandalize performance or the user experience. For example, Evercookie's CSS History Knocking can beget a deluge of background HTTP requests, and loading Silverlight or Flash can raise unsought permission modals or thrash the user's disk.
When you store a key-value pair in ImmortalDB, that key and value are saved redundantly in the browser's cookies, IndexedDB, and LocalStorage data stores.
When a value is retrieved via its key, ImmortalDB
- Looks up that key in every data store.
- Counts each unique returned value.
- Determines the most commonly returned unique value as the 'correct' value.
- Returns this correct value.
Then ImmortalDB self-heals: if any data store(s) returned a value different than the determined correct value, or no value at all, the correct value is rewritten to that store. In this way, consensus, reliability, and redundancy is maintained.
ImmortalDB's API is simple. To store a value, use set(key, value):
import { ImmortalDB } from 'immortal-db'
await ImmortalDB.set('key', 'value')key and value must be
DOMStrings.
ImmortalDB.set(key, value) also always returns value, so it can be chained or
embedded, like
const countPlusOne = (await ImmortalDB.set('count', numberOfClowns)) + 1To retrieve a value, use get(key, default=null):
const value = await ImmortalDB.get('key', default=null)get() returns the value associated with key, if key exists. If key
doesn't exist, default is returned. key must be a
DOMString.
Finally, to remove a key, use remove(key):
ImmortalDB.set('hi', 'bonjour')
console.log(await ImmortalDB.get('hi')) // Prints 'bonjour'.
await ImmortalDB.remove('hi')
console.log(await ImmortalDB.get('hi')) // Prints 'null'.key must be a
DOMString.
The data stores that ImmortalDB stores data in can also be configured. For example, this is how to store data reliably in cookies and LocalStorage only:
import { ImmortalStorage, CookieStore, LocalStorageStore } from 'immortal-db'
const stores = [await CookieStore(), await LocalStorageStore()]
const db = new ImmortalStorage(stores)
await db.set(key, JSON.stringify({1:1}))By default, stores used by ImmortalDB are:
CookieStore-> Keys and values are stored indocument.cookie.IndexedDbStore-> Keys and values are stored inwindow.indexedDB.LocalStorageStore-> Keys and values are stored inwindow.localStorage.
Other, optional stores are:
SessionStorageStore-> Keys and values are stored inwindow.sessionStorage.
New storage implementations can easily be added, too; they need only
implement the async methods get(key, default), set(key, value), and
remove(key).
Installing ImmortalDB with npm is easy.
$ npm install immortal-db
Or include dist/immortal-db[.min].js and use window.ImmortalDB directly.
<html>
<head>
<script src="immortal-db.min.js"></script>
<script>
;(async () => {
const db = ImmortalDB.ImmortalDB
await db.set('hi', 'lolsup')
})()
</script>
</head>
...
</html>To test ImmortalDB, run
npm run start
This starts a webpack dev server and opens ImmortalDB's testing website, http://localhost:9234/.
Once tested, to produce new production-ready files immortal-db.js and
immortal-db.min.js in dist/, run
npm run build