eos开发实践

一下载前端代码
git clone https://github.com/baidang201/eos-todo

二安装nodejs
sudo apt-get install python-software-properties
curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
sudo apt-get install -y nodejs

安装完成后查看安装node版本，
$ node -v

v8.11.2
三安装项目依赖包
cd frontend
npm install

注意
1 npm install时，如果下载进度比较慢，报错如下
“
[ ...........] - postinstall: sill install executeActions
[ ...........] \ extract:asynckit: sill pacote data for sha512-d7nZf78irx
[ ...........] \ extract:asynckit: sill pacote data for sha512-d7nZf78irx
”

可以运行 npm config set registry https://registry.npm.taobao.org
然后编辑 ~/.npmrc 加入下面内容
registry=https://registry.npm.taobao.org
四运行前端
npm run start

eos-todo@1.0.0 start /home/li/Documents/todo-eos/frontend
webpack-dev-server --config webpack.config.js --mode development

(node:17274) DeprecationWarning: Tapable.plugin is deprecated. Use new API on .hooks instead
ℹ ｢wds｣: Project is running at http://localhost:8080/
ℹ ｢wds｣: webpack output is served from /
ℹ ｢wds｣: Content not from webpack is served from ./dist
ℹ ｢wdm｣: Hash: 9552624317d8b15cd9f3
Version: webpack 4.6.0
Time: 15143ms
Built at: 2018-06-04 22:34:00
Asset Size Chunks Chunk Names
bundle.js 2.63 MiB main [emitted] main
Entrypoint main = bundle.js
[./node_modules/eosjs/lib/index.js] 8.26 KiB {main} [built]
[./node_modules/loglevel/lib/loglevel.js] 7.68 KiB {main} [built]
[./node_modules/react-hot-loader/patch.js] 40 bytes {main} [built]
[./node_modules/react/index.js] 190 bytes {main} [built]
[./node_modules/strip-ansi/index.js] 161 bytes {main} [built]
[./node_modules/url/url.js] 22.8 KiB {main} [built]
[./node_modules/webpack-dev-server/client/index.js?http://localhost:8080] (webpack)-dev-server/client?http://localhost:8080 7.75 KiB {main} [built]
[./node_modules/webpack-dev-server/client/overlay.js] (webpack)-dev-server/client/overlay.js 3.58 KiB {main} [built]
[./node_modules/webpack-dev-server/client/socket.js] (webpack)-dev-server/client/socket.js 1.05 KiB {main} [built]
[./node_modules/webpack/hot sync ^./log$] (webpack)/hot sync nonrecursive ^./log$ 170 bytes {main} [built]
[0] multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server react-hot-loader/patch ./src/index.jsx 64 bytes {main} [built]
[./node_modules/webpack/hot/dev-server.js] (webpack)/hot/dev-server.js 1.66 KiB {main} [built]
[./node_modules/webpack/hot/log-apply-result.js] (webpack)/hot/log-apply-result.js 1.31 KiB {main} [built]
[./node_modules/webpack/hot/log.js] (webpack)/hot/log.js 1.03 KiB {main} [built]
[./src/index.jsx] 8.44 KiB {main} [built]
+ 651 hidden modules
ℹ ｢wdm｣: Compiled successfully.

五打开浏览器，访问“localhost:8080”
image.png
注意
运行前端，报错“已拦截跨源请求：同源策略禁止读取位于 http://172.17.0.2:8888/v1/chain/get_code 的远程资源。”
=》（原因：CORS 头缺少 'Access-Control-Allow-Origin'）
跨域请求问题，要设置config.ini，把access-control-allow-origin access-control-allow-headers 属性做如下修改(config.ini目录/home/li/.local/share/eosio/nodeos/config/config.ini)

access-control-allow-origin = *
access-control-allow-headers = Origin, X-Requested-With, Content-Type, Authorization, X-Custom-Header
六总结
1 eosjs在react的使用
《1 导入eosjs库
《2 生成eosjs对象
《3 加载合约
《4 调用合约内方法

import EOS from 'eosjs'
const EOS_CONFIG = {
contractName: "bytemaster", // Contract name,who create contract
contractSender: "bytemaster", // User executing the contract (should be paired with private key),who run contract
clientConfig: {
keyProvider: ['5Ke4aKjY9PGZJnxNV54REsGUqQqRZNpJKr6unnkWLmU1oTT16Cw'], // Your private key
httpEndpoint: 'http://127.0.0.1:8888' // EOS http endpoint
}
}

let eosjs = EOSJS.Localnet(EOSJS_CONFIG, clientConfig)
eos.js.contract(EOS_CONFIG.contractName)
.then((contract) = >{
console.log(EOS_CONFIG.contractName + 'load contract ok!')

eosjs.getTableRows({
"scope": EOS_CONFIG.contractName,
"code": EOS_CONFIG.contractName,
"table": "todos",
"json": true
})
.then(result = >{
console.log(EOS_CONFIG.contractName + 'read data ok!')

  let rows = result.rows
  let len = rows.length
  for (let i = 0; i < len; i++) {
      var id = result.rows[i].id
      //...
  }

})
.catch((err) = >{
console.error(e);
})

})
七引用
https://steemit.com/eos/@eos-asia/part-2-building-a-to-do-list-with-eos-or-working-with-persistent-data-in-eos 《Part 2: Building a To-do list with EOS》

https://mp.weixin.qq.com/s/QVzKIrhYpw7JdrWe38TEJw《[EOS智能合约]第二节：用EOS开发一个To-do List小应用》

https://github.com/eosasia/eos-todo 《todolis前端源码》
https://github.com/EOSIO/eosjs 《EOSJS前端源码，及使用简介》

作者：剑有偏锋
链接：https://www.jianshu.com/p/745548d36ccc
來源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。

eos开发实践

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