获取示例合约
我们准备了一个非常简单的合约，里面只包含两个文件：config.yaml 和 protocol.proto
config.yaml
定义合约的名称，版本号，以及合约所依赖的几个文件，这里我们只有 1 个数据结构定义的文件。
---
name: create_product
version: 1
namespace: CoreTx
description: Create product that can be sold within the vending machine
type_urls:
fg:t:create_product: ForgeAbi.CreateProductTx
fg:x:product: ForgeAbi.Product
proto: protocol.proto
protocol.proto
定义合约里面会使用到的数据结构，和新的交易类型。
syntax = "proto3";
package forge_abi;
message CreateProductTx {
Product product = 1;
}
message Product {
string name = 1;
string brand = 2;
}
上面的代码已经放到了 GitHub 上面，获取方式比较简单：
git clone https://github.com/wangshijun/forge-product-factory-contract.git
cd forge-product-factory-contract
准备编译环境
TODO: 这里应该需要额外安装几个工具
编译合约文件
接下来直接执行 forge contract:compile ./protocol，得到如下输出：
❯ forge contract:compile protocol
ℹ Contract meta: {"name":"create_product","version":1}
ℹ Generating elixir language support:
✔ Latest forge compiler version: v0.18.2
✔ forge-compiler info fetch success
ℹ Start download https://releases.arcblock.io/forge-compiler/0.18.2/forge-compiler
ℹ Downloading forge-compiler |████████████████████████████████████████ 100% || 2.84/2.84 MB
✔ Elixir itx generated: .compiled/create_product/elixir/create_product/create_product.itx.json
ℹ Generating JavaScript language support:
✔ Protobuf js generated: .compiled/create_product/javascript/protocol_pb.js
✔ JSON spec generated: .compiled/create_product/javascript/protocol_spec.json
✔ type_urls json generated: .compiled/create_product/javascript/protocol_url.json
✔ JavaScript entry file generated: .compiled/create_product/javascript/index.js
如果是第一次执行 forge contract:compile，Forge CLI 会自动去下载合约编译工具 forge-compiler。
当前的 contract:compile 能产生能够给 Forge Elixir SDK 和 Forge JS SDK 使用的文件，也产生了可以直接用于部署到链节点的结果文件。
部署合约
如果要部署合约直接执行：forge protocol:deploy .compiled/create_product/elixir/create_product/create_product.itx.json，结果如下：
❯ forge contract:deploy .compiled/create_product/elixir/create_product/create_product.itx.json
ℹ Working on app-chain chain
ℹ Connect to grpc endpoint: tcp://127.0.0.1:28210
✔ Moderator checked success
ℹ Deploy contract to tcp://127.0.0.1:28210
Contract detail:
{ address: 'z2E3q3PUNCzMNvKi1RuT7KHJ7VnUGZMhjPQwF',
name: 'create_product',
version: 1,
namespace: 'CoreTx',
description: 'Create product that can be sold within the vending machine',
typeUrlsList:
[ { url: 'fg:t:create_product',
module: 'ForgeAbi.CreateProductTx' },
{ url: 'fg:x:product', module: 'ForgeAbi.Product' } ],
proto:
'syntax = "proto3";\npackage forge_abi;\n\nmessage CreateProductTx {\n Product product = 1;\n}\n\nmessage Product {\n string name = 1;\n string brand = 2;\n}\n',
pipeline: '',
sourcesList: [],
codeList:
[ { checksum: [Uint8Array], binary: [Uint8Array] },
{ checksum: [Uint8Array], binary: [Uint8Array] } ],
tagsList: [],
data: undefined }
✔ Contract deploy success
ℹ Inspect tx with forge tx 6800DF1ED99D3A5B9F41C2F54A2644CC4F34A42DAF57B8889E6418553A9EF6F1
相同名称、相同版本的合约是不允许重复部署的，所以，如果合约代码有改动，需要递增版本号，重新编译，然后再部署。
验证部署结果
执行 forge contract:ls | grep create_product，如果能看到结果，说明部署正常。
❯ forge contract:ls | grep create_product
│ create_product │ z2E3q3PUNCzMNvKi1RuT7KHJ7VnUGZMhjPQwF │ running │ v1 │
使用编译后的代码
在 wangshijun/forge-product-factory-contract 有如何在 Forge JS SDK 中使用编译后代码的例子：
/* eslint-disable no-console */
require('./.compiled/create_product/javascript/index');
const moment = require('moment');
const GraphqlClient = require('@arcblock/graphql-client');
const { toAssetAddress } = require('@arcblock/did-util');
const { fromTokenToUnit } = require('@arcblock/forge-util');
const { fromRandom, WalletType } = require('@arcblock/forge-wallet');
const endpoint = process.env.FORGE_API_HOST || 'http://127.0.0.1:8210'; // testnet
const client = new GraphqlClient(`${endpoint}/api`);
const sleep = timeout => new Promise(resolve => setTimeout(resolve, timeout));
(async () => {
try {
const merchant = fromRandom();
const customer = fromRandom();
console.log({ merchant: merchant.toJSON(), customer: customer.toJSON() });
// 1. declare merchant
let res = await client.sendDeclareTx({
tx: { itx: { moniker: 'merchant' } },
wallet: merchant,
});
console.log('merchant declare tx', res);
console.log('merchant view link', `${endpoint}/node/explorer/accounts/${merchant.toAddress()}`);
// 2. create vendor machine
const machine = {
moniker: `Vending_Machine_${merchant.toAddress()}`,
readonly: false, // if we want to update the machine, we should set this to false
transferrable: false,
data: {
type: 'AssetFactory',
value: {
description: 'Unlimited Vending Machine',
limit: 99999,
price: {
value: Buffer.from(fromTokenToUnit(1).toBuffer()),
},
template: JSON.stringify({ name: '{{name}}', brand: '{{brand}}' }),
allowedSpecArgs: ['name', 'brand'],
assetName: 'Product',
attributes: {
transferrable: false,
},
},
},
};
const assetAddress = toAssetAddress(machine);
machine.address = assetAddress;
res = await client.sendCreateAssetTx({ tx: { itx: machine }, wallet: merchant });
console.log('factory template', machine.data.value.template);
console.log('view machine state', `${endpoint}/node/explorer/assets/${assetAddress}`);
console.log('create machine tx', `${endpoint}/node/explorer/txs/${res}`);
// wait for machine state consolidates
await sleep(3000);
// 3. read machine
const { state } = await client.getAssetState({ address: assetAddress });
console.log('machine state', state);
// 4. declare customer
res = await client.declare({ moniker: 'customer', wallet: customer });
console.log('customer declare tx', res);
console.log('customer view link', `${endpoint}/node/explorer/accounts/${customer.toAddress()}`);
// 5. get some money
res = await client.checkin({ wallet: customer });
console.log('poke tx', res);
console.log('poke link', `${endpoint}/node/explorer/txs/${res}`);
await sleep(3000);
// 6. create product and its address
const product = {
ttl: 0,
readonly: true,
transferrable: false,
parent: machine.address,
data: {
type: 'Product',
value: { name: 'Coca', brand: 'Pepsi' },
},
};
const goodAddress = toAssetAddress(product);
console.log('product value', product.data.value);
// 7. acquire asset
res = await client.sendAcquireAssetTx({
tx: {
itx: {
to: machine.address,
specs: [
{
address: goodAddress,
data: JSON.stringify(product.data.value),
},
],
},
},
wallet: customer,
});
console.log('product spec', {
address: goodAddress,
data: JSON.stringify(product.data.value),
});
console.log('product address', goodAddress);
console.log('acquire tx', res);
console.log('acquire link', `${endpoint}/node/explorer/txs/${res}`);
} catch (err) {
console.error(err);
console.log(JSON.stringify(err.errors));
}
})();