CPChain TypeScript SDK

This is the SDK for developing on CPChain with TypeScript(JavaScript).

Getting Started

npm install cpchain-typescript-sdk

Example code:

import cpc from 'cpchain-typescript-sdk'

// Create a wallet
const wallet = cpc.wallets.createWallet()

console.log(wallet.address)

// Check current blocknumber on testnet
const provider = cpc.providers.createJsonRpcProvider('https://testnet.cpchain.io')
provider.getBlockNumber().then(num => {
  console.log(num)
})

// Get balance of your wallet
provider.getBalance(wallet.address).then(balance => {
  console.log('Balance:', cpc.utils.formatCPC(balance))
})

API

Wallets

Create Wallet

You can create a new wallet as below:

import cpc from 'cpchain-typescript-sdk'

// Create a wallet
const wallet = cpc.wallets.createWallet()

console.log(wallet.address)

Generate Keystore

const password = '123456'

wallet.encrypt(password).then(encryptedJson => {
    console.log(encryptedJson)
})

Sign and Send Transactions

const wallet = // ...
const provider = createJsonRpcProvider('https://civilian.testnet.cpchain.io')

const transaction = {
    type: 0,
    to: address,
    value: utils.parseCPC('1'),
    nonce: await provider.getTransactionCount(address), // get Nonce
    gas: 300000,
    gasPrice: await provider.getGasPrice(), // get current Gas price
    chainId: 41
}
// 使用 cpchain/chain 生成的交易哈希
const rawTx = await wallet.signTransaction(transaction)

// submit tx
const response = await provider.sendTransaction(rawTx)
const receipt = await response.wait()

console.log(receipt.status)

Import Wallet

You can import a wallet by private key or mnemonic or keystore:

// private key
const wallet1 = wallets.createWallet(privateKey)

// mnemonic
const mnemonic = 'uniform hole fabric shock potato such rough provide nasty second dirt waste'
const wallet2 = wallets.fromMnemonic(mnemonic)

// keystore
const wallet3 = wallets.fromEcryptedJson(encryptedJson)

Providers

JsonRPCProviders

// Create a provider
const provider = createJsonRpcProvider('https://civilian.cpchain.io')

// Access chain data
const number = await provider.getBlockNumber()
const balance = await provider.getBalance('0xfe8c03415df612dc0e8c866283a4ed40277fa48b')

console.log(utils.formatCPC(balance))

Contracts

We wrote a test contract, please check it at fixtures/contracts/example. Below is the code of the example contract:

pragma solidity ^0.4.24;

contract Example {
    event ModifyName(string name, uint256 blockNumber);
    string name;
    address owner;

    constructor() public {
        name = "world";
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function greet() public view returns (string) {
        return string(abi.encodePacked("Hello, ", name));
    }

    function modify(string newName) public payable {
        name = newName;
        emit ModifyName(name, block.number);
    }

    function collectBack() onlyOwner public {
        msg.sender.transfer(address(this).balance);
    }
}

Note: If you want to develop smart contract on CPChain, please use this tool to help you create project: cpchain-cli.

Deploy Contracts

// const wallet = ...
// const provider = ...

const account = wallet.connect(provider)

const bytecode = fs.readFileSync('fixtures/contracts/example/Example_sol_Example.bin').toString()
const abi = JSON.parse(fs.readFileSync('fixtures/contracts/example/Example_sol_Example.abi').toString())

const exampleContractFactory = new contract.ContractFactory(abi, bytecode, account)

const exampleContract = await exampleContractFactory.deploy()

console.log(exampleContract.address)

Call Methods

// call view methods
console.log(await exampleContract.greet())
// output: hello, world!

// call payable methods
const tx = await exampleContract.modify('cpchain')

await tx.wait()

console.log(await exampleContract.greet())
// output: hello, cpchain!

// call payable methods with sending CPC
const tx2 = await exampleContract.modify('cpchain', {
    value: utils.parseCPC('1')
})
await tx2.wait()
console.log(await getBalance(provider, exampleContract.address))

// collect CPC back to sender
await (await exampleContract.collectBack()).wait()
console.log(await getBalance(provider, exampleContract.address))

Listen and Query Events

// listen events
exampleContract.on('ModifyName', (name: string, blockNumber: any, event: any) => {
    console.log(name, blockNumber, event)
})

// get history events
const filterFrom = exampleContract.filters.ModifyName()
const currentBlock = await provider.getBlockNumber()
const historicalEvents = await exampleContract.queryFilter(filterFrom, currentBlock - 10, currentBlock)

console.log(historicalEvents)

Utils

// convert Wei to CPC
utils.formatCPC(1)

// convert CPC to Wei
utils.parseCPC('1')

Test

All tests wirte in test.

npm test

Build and Uses in Browser

You can build this SDK then uses in the browser.

npm run build

The bundle.min.js will be generated in dist floder. Import this file by script tag. Then there will be a global object CPChain which is accessible in your front-end code.