以太坊Solidity之Truffle框架的应用实践

Posted 2022-07-11 ╰つ栺尖篴夢ゞ

一、前言

• 安装 Solidity 的开发框架 Truffle 和安装 Truffle 的开发客户端，请参考我之前的博客：以太坊Solidity之Truffle的使用流程与集成指南。
• 在放工程的位置，创建一个文件夹 truffleTest，来做为工程根目录：

$ mkdir -p /Users/admin/develop/blockchain_workspace/truffleTest

二、初始化框架

• 进入到工程根目录下（现在应该是个空目录），并执行下述命令：

$ cd /Users/admin/develop/blockchain_workspace/truffleTest
$ truffle init

• 正确执行后，将得到下面这样的目录结构：

• 目录结构简单说明如下：
• • app/ - 应用文件运行的默认目录，这里面包括推荐的 javascript 文件和 css 样式文件目录，但可以完全决定如何使用这些目录；
• • contract/ - Truffle 默认的合约文件存放地址；
• • migrations/ - 存放发布脚本文件；
• • test/ - 用来测试应用和合约的测试文件；
• • truffle.js - Truffle 的配置文件。

三、放入合约

• 删除 ./contract 目录下的自带 demo 合约，切记不要删除 ./contract/Migrations.sol 合约，它是 Truffle 用来帮助部署的：

$ cd /Users/admin/develop/blockchain_workspace/truffleTest/contracts
$ rm ConvertLib.sol MetaCoin.sol

• 在 ./contract 目录下创建一个自己的合约文件 Greeter.sol：

pragma solidity ^0.4.0;

contract Greeter 
    address creator;     
    string greeting;     

    function Greeter(string _greeting) public 
        creator = msg.sender;
        greeting = _greeting;
    

    function greet() constant returns (string) 
        return greeting;
    
    
    function setGreeting(string _newgreeting) 
        greeting = _newgreeting;
    
    
     /**********
     Standard kill() function to recover funds 
     **********/
    function kill()  
        if (msg.sender == creator)
            suicide(creator);  // kills this contract and sends remaining funds back to creator
    

四、修改发布脚本

• 将 ./migrations/2_deploy_contracts.js 下的内容由：

module.exports = function(deployer) 
  deployer.deploy(ConvertLib);
  deployer.autolink();
  deployer.deploy(MetaCoin);
;

• 修改为：

module.exports = function(deployer) 
  deployer.deploy(Greeter);
;

• 目的是去掉原有自带的 Demo 部署流程，修改为要部署的合约，修改完后，记得保存，不然发布时会报错，找不到相关合约。

五、编译

• 进入到工程根目录 ./truffleTest 目录下，进行编译：

$ truffle compile
Compiling Greeter.sol...

Writing artifacts to ./build/contracts

六、启动客户端

• 启动之前安装好的 EthereumJS RPC 客户端：

$ testrpc

EthereumJS TestRPC v3.0.3

Available Accounts
==================

Private Keys
==================

HD Wallet
==================
Mnemonic:      degree debate income mask fiber issue album diet unfair police race car
Base HD Path:  m/44'/60'/0'/0/account_index

Listening on localhost:8545

七、部署合约（migrate）

• 部署合约到网络上：

$ truffle migrate
Running migration: 2_deploy_contracts.js
  Deploying Greeter...
  Greeter: 0xe66038995cf64b14da96d26cbe1c96d30dec0e95
Saving successful migration to network...
Saving artifacts...

• 备注：
• • 如果报错出现了一些之前编译部署过，但已经不需要的合约，可以用 truffle migrate --reset 来重置部署，但可能根据情况，需要更新移植版本号，来管理不同的版本；
• • 若误删 Truffle 自带用来部署的合约 ./contracts/Migrations.sol，会出现下述报错，需要补回到 ./contract 目录，重初始化一次得到。

$ truffle migrate
Running migration: 1_initial_migration.js
/Users/admin/develop/blockchain_workspace/truffleTest/migrations/1_initial_migration.js:2
  deployer.deploy(Migrations);
                  ^

ReferenceError: Migrations is not defined
    at module.exports (/Users/admin/develop/blockchain_workspace/truffleTest/migrations/1_initial_migration.js:2:19)
    at /usr/local/lib/node_modules/truffle/lib/migrate.js:109:7
    at /usr/local/lib/node_modules/truffle/lib/require.js:82:7
    at tryToString (fs.js:425:3)
    at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:412:12)

八、最终效果

• 使用 truffle console 功能在控制台与合约交互，来看下效果：

$ truffle console
truffle(default)> Greeter.deployed().setGreeting("Hello world!");
'0xf6a00b4466c9ab38d7eb60dc9f8d15f5f1e500e24ea91bd9e28f6233bad08aed'
truffle(default)> Greeter.deployed().greet.call();
'Hello world!'
truffle(default)>

九、常见报错

• 以太坊客户端连接配置不正确，或未正常启动时：

$ truffle console
/usr/local/lib/node_modules/truffle/lib/repl.js:25
    if (err) return done(err);
                    ^

ReferenceError: done is not defined
    at /usr/local/lib/node_modules/truffle/lib/repl.js:25:21
    at /usr/local/lib/node_modules/truffle/lib/repl.js:57:21
    at /usr/local/lib/node_modules/truffle/lib/contracts.js:46:25
    at /usr/local/lib/node_modules/truffle/node_modules/web3/lib/web3/property.js:119:13
    at /usr/local/lib/node_modules/truffle/node_modules/web3/lib/web3/requestmanager.js:82:20
    at exports.XMLHttpRequest.request.onreadystatechange (/usr/local/lib/node_modules/truffle/node_modules/web3/lib/web3/httppro
vider.js:114:13)
    at exports.XMLHttpRequest.dispatchEvent (/usr/local/lib/node_modules/truffle/node_modules/xmlhttprequest/lib/XMLHttpRequest.
js:591:25)
    at setState (/usr/local/lib/node_modules/truffle/node_modules/xmlhttprequest/lib/XMLHttpRequest.js:610:14)
    at exports.XMLHttpRequest.handleError (/usr/local/lib/node_modules/truffle/node_modules/xmlhttprequest/lib/XMLHttpRequest.js
:532:5)
    at ClientRequest.errorHandler (/usr/local/lib/node_modules/truffle/node_modules/xmlhttprequest/lib/XMLHttpRequest.js:459:14)
    at emitOne (events.js:96:13)
    at ClientRequest.emit (events.js:188:7)
    at Socket.socketErrorListener (_http_client.js:309:9)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at emitErrorNT (net.js:1281:8)

• 若合约未进行部署就进行调用，可能出现下述报错：

truffle(default)> Greeter.deployed().setGreeting("Hello world!");
Error: Cannot find deployed address: Greeter not deployed or address not set.
    at Function.Contract.deployed (/Users/admin/develop/blockchain_workspace/truffleTest/build/contracts/Greeter.sol.js:311:1
3)
    at evalmachine.<anonymous>:1:-53

    at ContextifyScript.Script.runInContext (vm.js:37:29)
    at Object.exports.runInContext (vm.js:69:17)
    at TruffleInterpreter.interpret (/usr/local/lib/node_modules/truffle/lib/repl.js:99:17)
    at bound (domain.js:280:14)
    at REPLServer.runBound [as eval] (domain.js:293:12)
    at REPLServer.onLine (repl.js:513:10)
    at emitOne (events.js:96:13)
    at REPLServer.emit (events.js:188:7)

• 部署时填合约名称有误，本应该写为 deployer.deploy(IntegerLiteral);，却写成了 deployer.deploy(“IntegerLiteral”);：

Deploying undefined...
Error encountered, bailing. Network state unknown. Review successful transactions manually.
TypeError: Cannot read property 'apply' of undefined
    at /usr/local/lib/node_modules/truffle/lib/deployer.js:62:28
    at process._tickDomainCallback (internal/process/next_tick.js:129:7)