cycle-gun

cycle-gun

A cycle.js driver that wraps a gun.js store instance.

Note: This driver currently depends on the xstream library.

Overview

• Gun.js store is created inside a cycle driver pointing to an optional peer.
• The source from the Gun driver is an object with 3 methods: select, shallow, and each
• The sink stream emits "command" functions which take the gun.js instance and apply some changes to it using the normal Gun.js API

Installation

npm install --save cycle-gun

GunSource

The source from the Gun.js driver is an object with some methods that return streams.

Use gunSource.select('books') to go to the books path in the graph. It returns a new gunSource object.

Use gunSource.shallow() to get a Stream of the data under the current path. This is equivalent to Gun's .on(callback) API.

const presidentAge$ = sources.gun
  .select('president').shallow()
  .map(x => {
    // x is the data for `president`
    return x.age;
  })

Use gunSource.each() to get a Stream of the data under each child property of the current path. This is equivalent to Gun's .map().on(callback) API. The return stream will emit an object {key, value}. This method is useful when the current path points to a set of many resources.

const book$ = sources.gun
  .select('books').each()
  .map(x => {
    // x is an object {key, value} representing ONE book
    return x.value;
  })

Sinking commands to gun driver

In this version, we can send commands to the gun driver by sending a function through the sink stream with payload references.

const outgoingGunTodo$ = event$
  .map((event) => function command(gunInstance) {
    return gunInstance
      .get('example/todo/data')
      .path(uuid())
      .put(event.payload);
  })

A more detailed example

Note: virtual-dom details omitted and transducers are verbose here

import xs from 'xstream';
import { run } from '@cycle/run';
//import { makeDOMDriver } from '@cycle/dom';
import { makeGunDriver } from 'cycle-gun';
import * as uuid from 'uuid-random';
import * as equal from 'deep-equal';
import dropRepeats from 'xstream/extra/dropRepeats';

function main(sources) {

  const {DOM, gun} = sources;

  const gunTodoEvent$ = sources.gun
    .select('example').select('todo').select('data')
    .shallow();

  // map gun driver events into messages, or return as state
  const gunState$ = gunTodoEvent$
    .compose(dropRepeats(equal))
    .map((event) => {
      return { typeKey: 'getTodo', payload: event };
    })

  // sink gunState$ into a flux-type store or into vdom




  // sink map filtered stream of payloads into function and emit function
  const outgoingGunEvents$ = event$
    .filter(event => event.typeKey === 'putTodo')
    .map((event) => {
      return (gunInstance) => {
        return gunInstance.get('example/todo/data').path(uuid()).put(event.payload);
      }
    })

  return {
    // DOM: vtree$
    gun: outgoingGunEvents$
  };
}

const drivers = {
  // DOM: makeDOMDriver('#app'),
  gun: makeGunDriver({root: 'root', peers: ['http://localhost:3500']})
};

run(main, drivers);

Other cyclejs reources

Please see awesome-cyclejs - A curated list of awesome Cycle.js resources.

MIT License