如何从零开始搭建一个Truffle框架的DAPP应用
1 介绍了如何获取宠物商店的TRUFLLE框架代码,并完成部署的过程。
2 我们要实现一个用户姓名和年纪的输入和呈现页面,能更新智能合约上的用户名和年龄。重新输入用户名和年纪,点击按钮可更新智能合约的这2个变量信息。 3 3.1 创建目录,下载框架 首先创建好目录,下载宠物商店的代码框架。 duncanwang@ubuntu:~/work$ mkdir name-age duncanwang@ubuntu:~/work$ cd name-age duncanwang@ubuntu:~/work/name-age$ truffle unbox pet-shop Downloading... Unpacking... Setting up... Unbox successful. Sweet! Commands: Compile: truffle compile Migrate: truffle migrate Test contracts: truffle test Run dev server: npm run devduncanwang@ubuntu:~/work/name-age$ 3.2 创建智能合约代码 新建一个InfoContract.sol智能合约文件,并把它更新到./contracts目录下。 pragma solidity ^0.4.24; contract InfoContract { string name; uint age; event Instructor(string name, uint age); function setInfo(string _name, uint _age) public { name = _name; age = _age; emit Instructor(name, age); } function getInfo() public view returns(string, uint) { return (name, age); } } 3.3 增加合约相关的部署和测试代码 1) 增加合约部署测试
var MyContract = artifacts.require("./InfoContract.sol"); module.exports = function(deployer) { // deployment steps deployer.deploy(MyContract); }; 2) 增加测试文件 pragma solidity ^0.4.24; import "truffle/Assert.sol"; import "truffle/DeployedAddresses.sol"; import "../contracts/InfoContract.sol"; contract TestInfoContract { InfoContract info = InfoContract(DeployedAddresses.InfoContract()); string name; uint age; function testInfo() { info.setInfo("ABC", 10); (name, age) = info.getInfo(); Assert.equal(name, "ABC", "设置名字出错"); Assert.equal(age, 10, "设置年龄出错"); } } 3)修改配置文件
module.exports = { // See // for more about customizing your Truffle configuration! networks: { development: { host: "127.0.0.1", port: 8545, network_id: "*" // Match any network id } } }; 否则测试时会有找不到客户端提示。 duncanwang@ubuntu:~/work/name-age$ truffle test Could not connect to your Ethereum client. Please check that your Ethereum client: - is running - is accepting RPC connections (i.e., "--rpc" option is used in geth) - is accessible over the network - is properly configured in your Truffle configuration file (truffle.js) 3.4 验收测试智能合约 1)参考宠物商店的文章代码,在一个窗口启动一个ganache-cli 钱包。 duncanwang@ubuntu:~/work/name-age$ cd .. 2)编译智能合约
duncanwang@ubuntu:~/work/name-age$ truffle compile Compiling ./contracts/InfoContract.sol... Compiling ./contracts/Migrations.sol... Writing artifacts to ./build/contracts 3)智能合约验收命令。 测试成功的提示说明: duncanwang@ubuntu:~/work/name-age$ truffle test Using network 'development'. Compiling ./contracts/InfoContract.sol... Compiling ./test/TestInfoContract.sol... Compiling truffle/Assert.sol... Compiling truffle/DeployedAddresses.sol... Compilation warnings encountered: /home/duncanwang/work/name-age/test/TestInfoContract.sol:12:4: Warning: No visibility specified. Defaulting to "public". function testInfo() { ^ (Relevant source part starts here and spans across multiple lines). TestInfoContract ✓ testInfo (838ms) 1 passing (5s) 3.5 完成前端页面 完成以下2个文件的修改更新和上传。
把宠物商店的index.html的代码删除,替换为本文需要的框架代码。 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>First Truffle DApp Demo</title> <link rel="stylesheet" type="text/css" href="main.css"> </head> <body> <div class="container"> <h1> First Truffle DApp Demo</h1> <h2 id="info"></h2> <img id="loader" src="https://loading.io/spinners/double-ring/lg.double-ring-spinner.gif"> <label for="name" class="col-lg-2 control-label">姓名:</label> <input id="name" type="text"> <label for="name" class="col-lg-2 control-label">年龄:</label> <input id="age" type="text"> <button id="button">更新</button> </div> <script src="http://libs.baidu.com/jquery/2.1.1/jquery.min.js"></script> <script src="js/Web3.min.js"></script> <script src="js/truffle-contract.js"></script> <script src="js/app.js"></script>
2) app.js
App = { web3Provider: null, contracts: {}, init: function() { return App.initWeb3(); }, /*加载web3*/ initWeb3: function() { if (typeof web3 !== 'unDeFined') { App.web3Provider = web3.currentProvider web3 = new Web3(App.web3Provider); } else { App.web3Provider = new Web3.providers.HttpProvider("http://localhost:9545") web3 = new Web3(App.web3Provider); } return App.initContract(); }, /*初始化合约,获取合约,不需要使用at()的方式; 显示合约的姓名和年龄信息*/ initContract: function() { $.getJSON('InfoContract.json', function(data){ App.contracts.InfoContract = TruffleContract(data); App.contracts.InfoContract.setProvider(App.web3Provider); App.getInfo(); App.watchChanged(); }); App.bindEvents(); }, getInfo: function() { App.contracts.InfoContract.deployed().then(function(instance) { return instance.getInfo.call(); }).then(function(result) { $("#loader").hide(); $("#info").html(result[0]+' ('+result[1]+' years old)'); console.log(result); }).catch(function(err) { console.error(err); }); }, /*点击按钮更新姓名和年龄,则需要更新到智能合约上*/ bindEvents: function() { $("#button").click(function() { $("#loader").show(); App.contracts.InfoContract.deployed().then(function(instance) { return instance.setInfo($("#name").val(), $("#age").val(), {gas: 500000}); }).then(function(result) { return App.getInfo(); } ).catch(function(err) { console.error(err); }); }); }, watchChanged: function() { App.contracts.InfoContract.deployed().then(function(instance) { var infoEvent = instance.Instructor(); return infoEvent.watch(function(err, result) { $("#loader").hide(); $("#info").html(result.args.name +' ('+ result.args.age +' years old)'); }); }); } } $(function(){ $(window).load(function() { App.init(); }); }); 3.6 测试验收前端和合约交互代码 1) 部署合约
duncanwang@ubuntu:~/work/name-age$ truffle migrate Using network 'development'. Running migration: 1_initial_migration.js Deploying Migrations... ... 0x5b3cd41a7fa7c58361172ac797412469a10edfbe721d8d81988f19282c9cb6e4 Migrations: 0x92b6ecd23aa98fad36926c12ec701f9aaa0933f4 Saving successful migration to network... ... 0x826fcd5b72b48435bf4f9941305727e52b0b7290631ba7b39f642027b1ee6947 Saving artifacts... Running migration: 2_info_contract.js Deploying InfoContract... ... 0x9943dd7b90207bd9fd1e85524d1d0227f18a92269d73f5a2141cb71c22dda1e9 InfoContract: 0x191391c710e1b632e40b4f2267dbc0f3bdb2bed4 Saving successful migration to network... ... 0x7e11f6e32585524e338e73439e4026c7c766625e5d23d56a4c90f8a11e5001ed Saving artifacts... 2)安装并启动lite-server
【定义】lite-server 是轻量级的,仅适用于开发 的 node 服务器, 它仅支持 web app。 它能够为你打开浏览器, 当你的html或是JavaScript文件变化时,它会识别到并自动帮你刷新浏览器, 还能使用套接字自动注入变化的CSS, 当路由没有被找到时,它将自动后退页面。
duncanwang@ubuntu:~/work/name-age$ npm install lite-server --save-dev 成功安装的输出结果如下: npm WARN pet-shop@1.0.0 No description npm WARN pet-shop@1.0.0 No repository field. npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/fsevents): npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"ia32"}) + lite-server@2.4.0 added 342 packages from 273 contributors in 56.82s 2] 在新的窗口完成lite-server的启动。 duncanwang@ubuntu:~/work/name-age$ npm run dev > pet-shop@1.0.0 dev /home/duncanwang/work/name-age > lite-server ** browser-sync config ** { injectChanges: false, files: [ './**/*.{html,htm,css,js}' ], watchOptions: { ignored: 'node_modules' }, server: { baseDir: [ './src', './build/contracts' ], middleware: [ [Function], [Function] ] } } [Browsersync] Access URLs: -------------------------------------- Local: http://localhost:3000 External: http://10.225.18.149:3000 -------------------------------------- UI: http://localhost:3001 UI External: http://localhost:3001 -------------------------------------- [Browsersync] Serving files from: ./src [Browsersync] Serving files from: ./build/contracts [Browsersync] Watching files... 3)打开主页
4)更新姓名和年龄 输入框输入姓名和年龄:王登辉,18 ,点击更新按钮,会弹出MEATMASK的交易提示,确认交易。 确认交易后,姓名和年龄信息会更新。 4 本文仅从操作层面讲解了如何利用宠物商店的模板样例,快速重构一个含前端的DAPP页面。 |
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