Embarklabs Subspace Versions Save

Introducing Subspace React's components

A new set of components were created to simplify the usage of Subspace within React projects. Learn more about them here https://subspace.embarklabs.io/react.html

Install

You can install it through npm or yarn:

npm install --save @embarklabs/subspace-react web3 rxjs

Usage

SubspaceProvider

To use most of the subspace-react components, you need to wrap your app with the <SubspaceProvider web3={web3} /> component. This will make Subspace available to any nested components that accesses it via the useSubspace hook or has been wrapped in the withSubspace higher order component. Any React component might use Subspace so it makes sense to add the provider near the top level of your dApp. The SubspaceProvider requires a web3 object

// index.js
import React from 'react'
import ReactDOM from 'react-dom'
import MyApp from './MyApp'
import { SubspaceProvider } from '@embarklabs/subspace-react';

const web3 = new Web3("ws://localhost:8545");

const rootElement = document.getElementById('root')
ReactDOM.render(
  <SubspaceProvider web3={web3}>
    <MyApp />
  </SubspaceProvider>,
  rootElement
);

useSubspace

Rather than relying on global variables or passing Subspace through props, The easiest way to access Subspace features is via the useSubspace hook. Be sure that your entire dApp is wrapped with a <SubspaceProvider /> to have it available througout the component tree.

// index.js
import React from 'react'
import { useSubspace } from '@embarklabs/subspace-react';

const MyComponent = () => {
  const subspace = useSubspace();

  // do something....
  // subspace.trackBalance(web3.eth.defaultAccount);

  return ...;
}

export default MyComponent

withSubspace

This higher order component is provided as an alternative to the useSubspace hook. This injects the subspace property with an already initialized Subspace instance. Just like with the hook, your entire dApp needs to be wrapped with a <SubspaceProvider />.

// index.js
import React from 'react'
import { withSubspace } from '@embarklabs/subspace-react';

const MyComponent = (props) => {
  // do something....
  // props.subspace.trackBalance(web3.eth.defaultAccount);

  return ...;
}

export default withSubspace(MyComponent);

observe

Useful to make your component subscribe to any observable props it receives when the component is mounted and automatically unsubscribes when the component is unmounted. It can be used with any kind of observables. This component already existed in the previous version of Subspace. The only difference is that it has been moved to the subspace-react package.

import { observe } from '@embarklabs/subspace-react';

const ObserverComponent = observe(WrappedComponent);

Example usage:

const MyComponent = ({eventData}) =>  {
  // Handle initial state when no data is available
  if (!eventData) {
    return <p>No data</p>;
  }
  
  return <p>Value: {eventData.someReturnValue}</p>
};


const MyEnhancedComponent = observe(MyComponent);


const SomeOtherComponent = () => {
  const myObservable$ = MyContractInstance.events.MyEvent.track({fromBlock: 1});
  return <MyEnhancedComponent myProp={myObservable$} />;
}

Breaking changes

• Peer dependencies Installing subspace requires explicitly installing web3 and rxjs as peer depenencies, while before they were installed as dependencies of the package

npm install --save @embarklabs/subspace web3 rxjs

• Web3 In the previous version, Subspace received a web3.js provider in the constructor. This new version receives instead a Web3 object:

const web3 = new Web3("http://localhost:8545");
const subspace = new Subspace(web3);

• init() is async. This means that you need to wait until Subspace has been initialized to use its features:

await subspace.init();

• The observe higher-order component was moved from the @embarklabs/subspace package to the new @embarklabs/subspace-react package.

• If no call interval is specified in the Subspace options, it will use the average blocktime as the interval of time to poll the contract addresses for changes in state or balance.

Maintenance / Bug fixes

• Major refactor increasing the usage of observables within the subspace package: Subjects in tracking functions were replaced by observables (they still keep the same functionality), New blocks and interval timers are done via observables.
• Subscriptions to web3js are handled automatically depending on the number of subscribers. The subscriptions are kept if there is at least one observer subscribed to an observable, otherwise the subscription is closed and will be reopened once there's a new subscriber.
• The checksum of the address to be tracked is performed automatically when performing balance tracking
• Dropped the usage of web3-utils.
• Simplified the logic for tracking events
• Added Lerna to the repository to organize the different packages, as well as making the documentation part of the project
• Updated all the examples to use the latest subspace-react components

New methods available to track blocks, gas price and blocktime

trackBlock()

Returns the block information for any new block as soon as they are mined. It's the reactive equivalent to web3.eth.getBlock("latest").

subspace.trackBlock().subscribe(block => console.log(block));

trackBlockNumber()

Returns the latest block number. It's the reactive equivalent to web3.eth.getBlockNumber.

subspace.trackBlockNumber().subscribe(blockNumber => console.log(blockNumber));

trackGasPrice()

Returns the current gas price oracle. It's the reactive equivalent to web3.eth.getGasPrice.

subspace.trackGasPrice().subscribe(gasPrice => console.log(gasPrice));

trackAverageBlocktime()

Returns the moving average block time taking in account the latest 10 blocks. The time is returned in milliseconds:

subspace.trackAverageBlocktime().subscribe(blocktimeMS => console.log(blocktimeMS));

Bug fixes

• Web3 subscriptions are reused, which means that calling a track method with the same parameters more than once will not create a duplicate subscription.

Using babel instead of webpack to make Subspace tree-shakeable

Generally for a library, webpack is not used to produce the build in dist/. rather, but babel and let downstream projects make the choice of webpack or rollup, etc. Subspace's node and browser builds were heavy and there was no hope a downstream developer's build tools can treeshake.

This minor release uses babel to build the sources into dist/ for nodejs, lib/ for the browser and module/ for es6. A DApp (or project, generally speaking) that makes use of Subspace will, with its own front-end tooling (e.g. webpack or rollup, in the context of create-react-app for example) be responsible for tree shaking and creating builds.

In addition to this change, dependency versions were bumped up.

New Org

Subspace is now under the @embarklabs Org. Versions under @status-im Org have been deprecated.

# Using npm
npm install --save @embarklabs/subspace

# Using yarn
yarn add @embarklabs/subspace 

HttpProvider support

Previously Subspace only worked with WebSockets for event subscriptions, and polled for changes only if the callInterval option was specified, displaying a warning indicating that the use of providers other than WebSocketProvider was discouraged.

With this release, Subspace will identify if the provider supports subscriptions and use them automatically. If no subscriptions are available, it will assume the provider does not support them and poll the contract for new changes periodically.

Subscriptions can be disabled with the disableSubscriptions option.

let subspace = new Subspace({disableSubscriptions: true})

GraphQL Example

An example DApp using GraphQL with Subspace can now be found at https://github.com/embark-framework/subspace/tree/master/examples/react-graphql-example1 .

Bug fixes

• Fixed obtaining the from address when instantiating a Web3 Contract with Subspace tracking functionality
• .track() is added only to event names as they're specified in the ABI. Tracking events by signature is not allowed

Bug fixes

• Fixed tracking ERC20 balances with trackBalance using the address received as argument
• Fixed React HOC unsubscribes when component unmounts

Website and Documentation

The website and up to date documentation can be found at https://subspace.status.im

Track Logs

Added trackLogs() to react to incoming logs

subspace.trackLogs({address: tokenAddress, topics: [eventTopic1, eventTopic2, null]}).subscribe((v) => {
  console.log(v);
});

No DB option

In cases where you don't want persistence, you can now disable it with the disableDatabase option

let subspace = new Subspace({disableDatabase: true})

Vue Example

An example DApp using Vue with Subspace can now be found at https://github.com/embark-framework/subspace/tree/master/examples/vue

Bug fixes

• Fixed chain id awareness so that syncing works better when switching networks

Subspace is a framework agnostic JS library that embraces reactive programming with RxJS, by observing asynchronous changes in Smart Contracts, and providing methods to track and subscribe to events, changes to the state of contracts and address balances, and react to these changes and events via observables.

Subspace also takes care of syncing under the hood, saving & loading the state in a local database.

Instalation

npm install --save @status-im/subspace

Usage

Event Tracking & Event Sourcing

You can track events and react to their values. With Subspace observables doing event sourcing is easy.

import { $average, $latest } from "@status-im/subspace";

const rating$ = Product.events.Rating.track().map("rating"));

rating$.pipe($latest(5), $average()).subscribe((rating) => {
  console.log("average rating of the last 5 events is " + rating)
});

Tracking State

You can track changes to a contract state variable, by specifying the view function and arguments to call and query the contract

const productTitle$ = ProductList.methods.products(0).track().map("title");
productTitle$.subscribe((title) => console.log("product title is " + title));

Tracking balances

You can also track changes in both ETH and ERC20 token balances

const address = "0x0001020304050607080900010203040506070809";

subspace.trackBalance(address).subscribe((balance) => {
  console.log("ETH balance is ", balance)
});

subspace.trackBalance(address, "0x744d70fdbe2ba4cf95131626614a1763df805b9e").subscribe((balance) => {
  console.log("SNT balance is ", balance)
});

React Integration Example

note: Subspace is framework agnostic and can integrate with ANY framework.

Subspace can make any react component compatible with observables so you easily reactive components

import { observe } from "@status-im/subspace/react";

const ProductComponent = ({ maxRating, minRating, averageRating }) => {
  return <ul>
    <li><b>minimum rating: </b> {minRating}</li>
    <li><b>maximum rating: </b> {maxRating}</li>
    <li><b>average rating: </b> {averageRating}</li>
  </ul>;
};

const ReactiveProductComponent = observe(ProductComponent);

const Product = subspace.contract({abi, address});
const rating$ = Product.events.Rating.track().map("rating").pipe(map(x => parseInt(x)));

ReactDOM.render(
  <ReactiveProductComponent
    maxRating={rating$.pipe($max())}
    minRating={rating$.pipe($min())}
    averageRating={rating$.pipe($average())}
  />,
  document.getElementById('hello-example')
);