graphenejs-lib

GrapheneJS (graphenejs-lib)

Pure JavaScript Bitshares/Graphene library for node.js and browsers. Can be used to construct, sign and broadcast transactions in JavaScript, and to easily obtain data from the blockchain via public apis.

Most of this code was written by jcalfeee, my work was mostly just repackaging to a discrete npm package.

Setup

This library can be obtained through npm:

npm install graphene-crypto

Usage

Three sub-libraries are included: ECC, Chain and Serializer. Generally only the ECC and Chain libraries need to be used directly.

Chain

This library provides a websocket rpc connection and other utility functions to handle blockchain state. To obtain a websocket connection to the Openledger API and subscribe to any object updates, use the following code:

Api calls

var {Apis} = require("graphene-crypto");
Apis.instance("wss://bitshares.openledger.info/ws").init_promise.then((res) => {
    console.log("connected to:", res[0].network);
    Apis.instance().db_api().exec( "set_subscribe_callback", [ updateListener, true ] )
});

function updateListener(object) {
    console.log("set_subscribe_callback:\n", object);
}

The set_subscribe_callback callback (updateListener) will be called whenever an object on the blockchain changes. This is very powerful and can be used to listen to updates for specific accounts, assets or most anything else, as all state changes happens through object updates.

State container

The Chain library contains a complete state container called the ChainStore. The ChainStore will automatically configure the set_subscribe_callback and handle any incoming state changes appropriately. It uses Immutable js for storing its state, so all objects are return as immutable objects. It has its own subscribe method that can be used to register a callback that will be called whenever a state change happens.

The ChainStore has several useful methods to retrieve, among other things, objects, assets and accounts using either object ids or asset/account names. These methods are synchronous and will return undefined to indicate fetching in progress, and null to indicate that the object does not exist.

var {Apis, ChainStore} = require("graphene-crypto");

Apis.instance("wss://bitshares.openledger.info/ws").init_promise.then((res) => {
    console.log("connected to:", res[0].network);
    ChainStore.init().then(() => {
        ChainStore.subscribe(updateState);
    });
});

let dynamicGlobal = null;
function updateState(object) {
    dynamicGlobal = ChainStore.getObject("2.1.0");
    console.log("ChainStore object update\n", dynamicGlobal ? dynamicGlobal.toJS() : dynamicGlobal);
}

ECC

The ECC library contains all the crypto functions for private and public keys as well as transaction creation/signing.

Private keys

As a quick example, here's how to generate a new private key from a seed (a brainkey for example):

var {PrivateKey, key} = require("graphene-crypto");

let seed = "THIS IS A TERRIBLE BRAINKEY SEED WORD SEQUENCE";
let pkey = PrivateKey.fromSeed( key.normalize_brainKey(seed) );

console.log("\nPrivate key:", pkey.toWif());
console.log("Public key :", pkey.toPublicKey().toString(), "\n");

Transactions

TODO transaction signing example

ESDoc (beta)

npm i -g esdoc esdoc-es7-plugin
esdoc -c ./esdoc.json
open out/esdoc/index.html