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ipfs-live-db

Live CRDT DB over IPFS

Install

$ npm install ipfs-live-db --save

Import

In the browser environment, you can either use this library by including it and bundling your app together with it (using browserify or webpack, for instance), or you can

in Node.js or in a browser with a bundler:

const DB = require('ipfs-live-db')

Using a script tag in a browser

<!-- loading the minified version -->
<script src="https://unpkg.com/ipfs-live-db/dist/browser.min.js"></script>

<!-- loading the human-readable (not minified) version -->
<script src="https://unpkg.com/ipfs-live-db/dist/browser.js"></script>

Now you can access this library using the IpfsLiveDb on the global namespace. (In this case, replace DB on the examples below with IpfsLiveDb).

Instantiate

const db = DB([options])

Arguments:

• options (object):
  • ipfs: a js-ipfs options object
  • store (string, defaults to "memory"): a local store, represented by a string. Can either be:
    • "indexeddb": for in-browser persistence
    • "leveldb": for Node.js persistence
  • partition (string, mandatory): the partition this data belongs to. It's used to broadcast new record ids (so trackers can follow (and pin) the global partition state)

API

db.define([typeName:String, ]typeDefinition:Object)

Defines and returns a type.

const TodoList = db.define('TodoList', {
  type: 'Array',
  of: {
    name: 'TodoItem'
    type: 'Object'
  }
})

const list = TodoList()

You can chain them:

db.define('TodoItem', {
  type: 'Object'
})

const TodoList = db.define('TodoList', {
  type: 'Array',
  of: 'TodoItem' // not necessary if you don't want a CRDT
})

or simply nest them:

const TodoItem = db.define({
  type: 'Object'
})

const TodoList = db.define('TodoList', {
  type: 'Array',
  of: TodoItem
})

Built-in types

The basic types that come build-in are 'Map' and 'Array'. The rest is up to you.

Instantiate

db.create(type, id:String)

Creates an instance for a given type.

Depending on the base type, it returns either a specized Map or Array instance (see below).

Example:

const id = 'some id'
const item = db.create('TodoItem', id)

Map

item.get(key:String)

Returns the value for the key.

item.set(key:String, value:Any)

Sets the value for that key

item.delete(key:String)

Deletes a property

item.keys()

Returns all keys for all values

item.observe(observer:Function)

The observer is called whenever something on this object changes. The observer is called with one sole argument of the Event type, which has the following properties:

• event.type: The type of the event. "add" - a new key-value pair was added, "update" - an existing key-value pair was changed, or "delete" - a key-value pair was deleted)
• event.name`: The key of the changed property
• event.value: If event type is either "update" or "add", this property defines the new value of the key-value pair

item.observeDeep(observer:Function)

Same as .observe, but catches events from all children (if they support .observeDeep).

event.path specifies the path of the change event.

item.unobserve(observer:Function)

Deactivates an observer.

Array

item.insert(position:Number, contents:Array)

Inserts contents at position position.

item.push(contents)

Inserts contents at the end of the array.

item.delete(position, length)

Deletes content. The length parameter is optional and defaults to 1.

item.toArray()

Returns the complete content as an array.

item.get(position:Number)

Returns the content at a given position.

item.observe(observer:Function)

The observer is called whenever something on this object changes. The observer is called with one sole argument of the Event type, which has the following properties:

• event.type: The type of the event. "insert" - a set of values was inserted, "delete" - a set of values was deleted
• event.index: The position the operation occurred at.
• event.length: The number of positions affected.
• event.values: The values inserted (if event.type is "insert")
• event.oldValues: The values removed (if event.type is "delete")

item.observeDeep(observer:Function)

Same as .observe, but catches events from all children (if they support .observeDeep). event.path specifies the path of the change event.

item.unobserve(observer:Function)

Deactivates an observer.

License

MIT

Contribute

Feel free to join in. All welcome. Open an issue!

This repository falls under the IPFS Code of Conduct.

License

MIT