In the formal development environment, we generally do not use remix to compile and deploy contracts, but use goland to call web3 for development.
Web3 working mode :
1. Development environment
Create a react project using the footlock, initialize the NPM project, execute the following command, and create package.json, a file describing the properties of the current module.
npm init
All the way yes down.
The directory structure of the project is as follows:
2. web3 compile contract
2.1 Install the compiler
npm install --save solc
Will add dependencies in package.json
2.2 Write contract test.sol
pragma solidity ^0.4.0;
contract TestCon{
string str;
constructor(string _str) public{
str=_str;
}
function setValue(string _str)public{
str=_str;
}
function getValue() public view returns(string){
return str;
}
}
2.3 Compile file 01-compile.js
//导入solc编译器
let solc = require('solc') //0.4.25
let fs = require('fs')
//读取合约
let sourceCode = fs.readFileSync('./contracts/SimpleStorage.sol', 'utf-8')
// Setting 1 as second paramateractivates the optimiser
let output = solc.compile(sourceCode, 1)
// console.log('output :', output)
//{age : 17, name : 'lily', address : 'sz'}
module.exports = output['contracts'][':SimpleStorage']
2.3 Compile the contract
Excuting an order
node 01-compile.js
3. web3 deployment contract
let {
bytecode, interface} = require('./01-compile')
// console.log(bytecode)
// console.log(interface)
//1. 引入web3
let Web3 = require('web3')
//2. new 一个web3实例
let web3 = new Web3()
//3. 设置网络
web3.setProvider('http://localhost:7545')
const account = '0xd5957914c31E1d785cCC58237d065Dd25C61c4D0'
console.log('version :', web3.version)
// console.log(web3.currentProvider)
//1. 拼接合约数据 interface
let contract = new web3.eth.Contract(JSON.parse(interface))
//2. 拼接bytecode
contract.deploy({
data: bytecode, //合约的bytecode
arguments: ['HelloWorld'] //给构造函数传递参数，使用数组
}).send({
from: account,
gas: '3000000',
//gasPrice: '1',
}).then(instance => {
console.log('address :', instance.options.address)
})
4. Get the contract instance
//获取合约实例，导出去
//let {bytecode, interface} = require('./01-compile')
//1. 引入web3
let Web3 = require('web3')
//2. new 一个web3实例
let web3 = new Web3()
//3. 设置网络
web3.setProvider('http://localhost:7545')
let abi = [{
"constant":true,"inputs":[],"name":"getValue","outputs":[{
"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{
"constant":false,"inputs":[{
"name":"_str","type":"string"}],"name":"setValue","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{
"inputs":[{
"name":"_str","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]
let address = '0x0FE5006b70A0D58AD3c4d4BC9DAC02C970510Cf6'
//此处abi已经json对象，不需要进行parse动作
let contractInstance = new web3.eth.Contract(abi, address)
console.log('address :', contractInstance.options.address)
module.exports = contractInstance
5. Call the contract
//1. 导入合约实例
//2. 读取数据
//3. 写入数据
//4. 读取数据
let instance = require('./03-instance')
const from = '0xd5957914c31E1d785cCC58237d065Dd25C61c4D0'
//异步调用，返回值是一个promise
//2. 读取数据
instance.methods.getValue().call().then(data => {
console.log('data:', data)
//3. 写入数据
instance.methods.setValue('Hello HangTou').send({
from: from,
value: 0,
}).then(res => {
console.log('res : ', res)
//4. 读取数据
instance.methods.getValue().call().then(data => {
console.log('data2:', data)
})
})
})
6. Use promise to rewrite
//web3与区块链交互的返回值都是promise，可以直接使用async/await
let test = async () => {
try {
let v1 = await instance.methods.getValue().call()
console.log('v1:', v1)
let res = await instance.methods.setValue('Hello HangTou').send({
from: from,
value: 0,
})
console.log('res:', res)
let v2 = await instance.methods.getValue().call()
console.log('v2:', v2)
} catch (e) {
console.log(e)
}
}
test()