English | 简体ä¸ć–‡
This demo shows the entire process of building a MVP DApp on CITA.
We provider three situations:
- run in PC and mobile browser directly: set
REACT_APP_RUNTIME=web
in.env
- run in PC and mobile browser directly, generate random private key :set
REACT_APP_RUNTIME=webRandomPk
in.env
- run in cita-web-debugger: set
REACT_APP_RUNTIME=cita-web-debugger
in.env
- run in cyton wallet App: set
REACT_APP_RUNTIME=cyton
inenv
Notice: This tutorial is for the developers who is able to build webapps and has basic knowledge of Blockchain and Smart Contract.
Before you start a tour, you may need to install node.js firstly.
Recommended node environment: v10.16.3
All interactions with Smart Contract are:
-
Store Text in Smart Contract: a
sendTransaction
action; -
Get TextList from Smart Contract: a
call
action; -
Get Text from Smart Contract: a
call
action;
The final project looks like
├── README.md
├── package.json
├── public
│  ├── favicon.ico
│  ├── index.html
│  └── manifest.json
├── src
│  ├── App.css
│  ├── App.js
│  ├── App.test.js
│  ├── Routes.jsx
│  ├── components
│  ├── config.js.example
│  ├── containers
│  ├── contracts
│  ├── index.css
│  ├── index.js
│  ├── logo.svg
│  ├── cita.js
│  ├── public
│  ├── registerServiceWorker.js
│  └── simpleStore.js
└── yarn.lock
1. git clone https://github.com/citahub/first-forever-demo
2. cd first-forever-demo
3. npm install
4. cp .env.example .env
5. cp ./src/config.js.example ./src/config.js
6. npm run deploy
contractAddress is: 0x21CE9960F395de32a5Deb99b8944d17Aa4561D25
7. copy address to config.js
const config = {
contractAddress: '0x21CE9960F395de32a5Deb99b8944d17Aa4561D25',
}
8. npm start
9. open "http://localhost:3000" and submit your first text to blockchain.
This Demo use create-react-app
to start the project, so you need the create-react-app
scaffold firstly
Notice: This demo is created by create-react-app and supported by modern browser. If es5 version needed, just eject the scaffold and add
@babel/preset-es2015
in.babelrc
The project can be initiated by
$ yarn create react-app first-forever && cd first-forever
Now the project looks like
├── README.md
├── package.json
├── public
│  ├── favicon.ico
│  ├── index.html
│  └── manifest.json
└── src
  ├── App.css
  ├── App.js
  ├── App.test.js
  ├── index.css
  ├── index.js
  ├── logo.svg
  ├── public
  └── registerServiceWorker.js
This step is very familiar to webapp developers, Route, Containers and Components will be added to the DApp
└── src
  ├── Routes.jsx
  ├── components
  └── containers
The Route indicates that the demo has 4 pages:
All above are just traditional webapp development, and next we are going to DApp development.
This step instructs how to have a DApp running on CITA.
The DApp interacts with CITA by the cita-sdk.js
and details of cita
can be accessed at @citahub/cita-sdk
In order to use cita-sdk.js, add cita-sdk as other packages by yarn yarn add @citahub/cita-sdk
, and then instantiate cita
in src/cita-sdk.js
.
const { default: CITASDK } = require('@citahub/cita-sdk')
const config = require('./config')
const cita = CITASDK(config.chain) // config.chain indicates that the address of CITA to interact
const account = cita.base.accounts.privateKeyToAccount(config.privateKey) // create account by private key from config
cita.base.accounts.wallet.add(account) // add account to cita
module.exports = cita
This DApp works with an extremely simple smart contract -- SimpleStore.
pragma solidity 0.4.24;
contract SimpleStore {
mapping (address => mapping (uint256 => string)) private records;
mapping (address => uint256[]) private categories;
event Recorded(address _sender, string indexed _text, uint256 indexed _time);
function _addToList(address from, uint256 time) private {
categories[from].push(time);
}
function getList()
public
view
returns (uint256[])
{
return categories[msg.sender];
}
function add(string text, uint256 time) public {
records[msg.sender][time]=text;
_addToList(msg.sender, time);
emit Recorded(msg.sender, text, time);
}
function get(uint256 time) public view returns(string) {
return records[msg.sender][time];
}
}
Smart Contract can be debugged on CITA-IDE, an online solidity debugger
By clicking on Detail
in the right-side panel, compiled details will show as follow
In details, bytecode and abi will be used in this demo.
bytecode is used to deploy the contract, and abi is used to instantiate a contract instance for interacting.
Create directory in src
├── contracts
│  ├── SimpleStore.sol
│  ├── compiled.js
│  ├── contracts.test.js
│  ├── deploy.js
│  └── transaction.js
-
Store SimpleStore Source Code in SimpleStore.sol
-
Store bytecode and abi in compiled.js
-
Store transaction template in transaction.js
const cita = require('../cita') const transaction = { from: cita.base.accounts.wallet[0].address, privateKey: cita.base.accounts.wallet[0].privateKey, nonce: '123abcXYZ', quota: 1000000, chainId: 1, version: 2, validUntilBlock: 999999, value: '0x0', } module.exports = transaction
-
Store deploy script in deploy.js
const cita = require('../cita') const { abi, bytecode } = require('./compiled.js') const transaction = require('./transaction') let _contractAddress = '' // contract contract instance const myContract = new cita.base.Contract(abi) cita.base .getBlockNumber() .then(current => { transaction.validUntilBlock = +current + 88 // update transaction.validUntilBlock // deploy contract return myContract .deploy({ data: bytecode, arguments: [], }) .send(transaction) }) .then(txRes => { if (txRes.hash) { // get transaction receipt return cita.listeners.listenToTransactionReceipt(txRes.hash) } else { throw new Error('No Transaction Hash Received') } }) .then(res => { const { contractAddress, errorMessage } = res if (errorMessage) throw new Error(errorMessage) console.log(`contractAddress is: ${contractAddress}`) _contractAddress = contractAddress return cita.base.storeAbi(contractAddress, abi, transaction) // store abi on the chain }) .then(res => { if (res.errorMessage) throw new Error(res.errorMessage) return cita.base.getAbi(_contractAddress).then(console.log) // get abi from the chain }) .catch(err => console.error(err))
-
Store test script in contracts.test.js
const cita = require('../cita') const { abi } = require('./compiled') const { contractAddress } = require('../config') const transaction = require('./transaction') const simpleStoreContract = new cita.base.Contract(abi, contractAddress) // instantiate contract cita.base.getBalance(cita.base.accounts.wallet[0].address).then(console.log) // check balance of account console.log(`Interact with contract at ${contractAddress}`) const time = new Date().getTime() const text = 'hello world at ' + time test(`Add record of (${text}, ${time})`, async () => { const current = await cita.base.getBlockNumber() transaction.validUntilBlock = +current + 88 // update transaction.validUntilBlock const txResult = await simpleStoreContract.methods.add(text, time).send(transaction) // sendTransaction to the contract const receipt = await cita.listeners.listenToTransactionReceipt(txResult.hash) // listen to the receipt expect(receipt.errorMessage).toBeNull() }, 10000) test(`Get record of (${text}, ${time})`, async () => { const list = await simpleStoreContract.methods.getList().call({ from: transaction.from, }) // check list const msg = await simpleStoreContract.methods.get(time).call({ from: transaction.from, }) // check message expect(+list[list.length - 1]).toBe(time) expect(msg).toBe(text) }, 3000)
-
Add deploy and test script in package.json
"scripts": { "deploy": "node ./src/contracts/deploy.js", "test:contract": "jest ./src/contracts/contracts.test.js" }
-
Create
src/config.js
, set private key and chain ip in it.$ cp src/config.js.example src/config.js
-
install dependencies
$ npm install
-
Deploy the contract
$ npm run deploy
-
Add contract address to config.js and test
For now the
config.js
should be like:const config = { chain: '{addr of net you are using}', privateKey: '{your private key}', contractAddress: '{deployed contract address}', } module.exports = config
Instantiate Contract in simpleStore.js under src
const cita = require('./cita')
const { abi } = require('./contracts/compiled.js')
const { contractAddress } = require('./config')
const transaction = require('./contracts/transaction')
const simpleStoreContract = new cita.base.Contract(abi, contractAddress)
module.exports = {
transaction,
simpleStoreContract,
}
In src/containers/Add/index.jsx
, bind the following method to submit button
handleSubmit = e => {
const { time, text } = this.state
cita.base
.getBlockNumber()
.then(current => {
const tx = {
...transaction,
validUntilBlock: +current + 88,
}
this.setState({
submitText: submitTexts.submitting,
})
return simpleStoreContract.methods.add(text, +time).send(tx) // execute add method to store memo in the contract
})
.then(res => {
if (res.hash) {
return cita.listeners.listenToTransactionReceipt(res.hash)
} else {
throw new Error('No Transaction Hash Received')
}
})
.then(receipt => {
if (!receipt.errorMessage) {
this.setState({ submitText: submitTexts.submitted })
} else {
throw new Error(receipt.errorMessage)
}
})
.catch(err => {
this.setState({ errorText: JSON.stringify(err) })
})
}
In src/containers/List/index.jsx
, load memos on mount
componentDidMount() {
const from = cita.base.accounts.wallet[0] ? cita.base.accounts.wallet[0].address : ''
simpleStoreContract.methods
.getList()
.call({
from,
})
.then(times => {
times.reverse()
this.setState({ times })
return Promise.all(times.map(time => simpleStoreContract.methods.get(time).call({ from })))
})
.then(texts => {
this.setState({ texts })
})
.catch(console.error)
}
In src/containers/Show/index.jsx
, load memo on mount
componentDidMount() {
const { time } = this.props.match.params
if (time) {
simpleStoreContract.methods
.get(time)
.call({
from: cita.base.accounts.wallet[0].address,
})
.then(text => {
this.setState({ time, text })
})
.catch(error => this.setState({ errorText: JSON.stringify(error) }))
} else {
this.setState({ errorText: 'No Time Specified' })
}
}
As all of these done, start the local server by npm start
to launch the DApp.
cita-web-debugger is an extension of chrome and debugger tool for CITA.
// src/cita-sdk.js
const { default: CITASDK } = require('@citahub/cita-sdk')
const config = require('./config')
const cita = CITASDK(config.chain) // config.chain indicates that the address of CITA to interact
const account = cita.base.accounts.privateKeyToAccount(config.privateKey) // create account by private key from config
// cita.base.accounts.wallet.add(account) // add account to cita
window.addEventListener('citaWebDebuggerReady', () => {
if (window.addMessenger) {
window.addMessenger(cita)
}
})
module.exports = cita
// src/index.js
window.addEventListener('citaWebDebuggerReady', () => {
setTimeout(() => {
ReactDOM.render(<App />, document.getElementById('root'))
}, 10)
})
// src/contracts/transaction.js
const cita = require('../cita')
const transaction = {
// from: cita.base.accounts.wallet[0].address,
// privateKey: cita.base.accounts.wallet[0].privateKey,
nonce: '123abcXYZ',
quota: 1000000,
chainId: 1,
version: 2,
validUntilBlock: 999999,
value: '0x0',
}
module.exports = transaction
// src/containers/add/index.jsx
const tx = {
...transaction,
from: cita.base.defaultAccount,
validUntilBlock: +current + 88,
}
// src/containers/List/index.jsx
// const from = cita.base.accounts.wallet[0] ? cita.base.accounts.wallet[0].address : ''
const from = cita.base.defaultAccount
// src/containers/Show/index.jsx
// from: cita.base.accounts.wallet[0].address,
from: cita.base.defaultAccount,
After these modification, first-forever-demo will work with cita-web-debugger perfectly.
Cyton is a blockchain wallet APP which supports CITA and Ethereum, it contains two platform versions: Android and iOS.
You just update little code to adapter Cyton (Android and iOS).
An CITA DApp needs to tell cyton wallet some information of the blockchain through manifest.json file, which contains chain name, chain id, node httpprovider etc.
As follows, we provide an example of manifest.json. In general, we suggest to put manifest.json in root directory of the project. If you have more than one chain, you should set more pairs of chain id and node httpprovider in chain set.
// public/manifest.json
{
"name": "CITA First Forever", // chain name
"blockViewer": "https://microscope.citahub.com/", // blockchain browser
"chainSet": { // a set of chainId and node httpprovider
"1": "https://testnet.citahub.com" // key is chainId, value is node httpprovider
},
"icon": "http://7xq40y.com1.z0.glb.clouddn.com/23.pic.jpg", // chain icon
"entry": "https://first-forever.citahub.com/", // DApp entry
"provider": "https://citahub.com/" // DApp provider
}
You should also set path of manifest.json in html file using link tag.
<link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
Then you also should update cita.js
.
const { default: CITASDK } = require('@citahub/cita-sdk')
// Cyton will provider cita object to dapp browser and dapp just update currentProivder and host
if (typeof window.cita !== 'undefined') {
window.cita = CITASDK(window.cita.currentProvider)
window.cita.currentProvider.setHost(config.chain)
} else {
console.log('No cita? You should consider trying Cyton!')
window.cita = CITASDK(config.chain)
}
var cita = window.cita
module.exports = cita
// src/contracts/transaction.js
const cita = require('../cita')
const transaction = {
nonce: '123abcXYZ',
quota: 1000000, // 10000 or 0xffff
chainId: 1,
version: 2,
validUntilBlock: 999999,
value: '0x0',
}
module.exports = transaction
// src/containers/add/index.jsx
const tx = {
...transaction,
from: window.cyton.getAccout(),
validUntilBlock: +current + 88,
}
// src/containers/List/index.jsx
// const from = cita.base.accounts.wallet[0] ? cita.base.accounts.wallet[0].address : ''
const from = window.cyton.getAccout()
// src/containers/Show/index.jsx
// from: cita.base.accounts.wallet[0].address,
from: window.cyton.getAccout(),
After these modification, first-forever-demo will work with cyton wallet perfectly.
If you have any mistakes in Android, you can debug in Chrome browser and input chrome://inspect
.
If you want to debug in iOS , you can debug in Safari browser.
Note: If you want to debug, you should download Android or iOS cyton project and build , install.