如何通过user_id在Flow中用TS/Python编程获取用户委托及奖励？

Flow的质押、委托及奖励数据都存储在链上的官方质押合约中，JS SDK（@onflow/fcl）其实支持通过执行Cadence脚本调用合约视图方法来获取这些数据，以下是TypeScript和Python的具体实现方案：

TypeScript 实现（基于@onflow/fcl） #

1. 安装依赖：

npm install @onflow/fcl

2. 核心代码：

import * as fcl from "@onflow/fcl";

// 配置网络（主网/测试网二选一）
fcl.config()
  .put("accessNode.api", "https://rest-mainnet.onflow.org") // 主网
  // .put("accessNode.api", "https://rest-testnet.onflow.org") // 测试网
  .put("0xFlowIDStaking", "0x8624b52f9ddcd04a"); // 主网质押合约地址，测试网为0x7e60df042a9c0868

async function getUserStakingData(userId: string) {
  // 构造获取委托信息的Cadence脚本
  const delegationScript = `
    import FlowIDStaking from 0xFlowIDStaking

    pub fun main(user: Address): FlowIDStaking.DelegationInfo? {
      return FlowIDStaking.getDelegationInfo(user)
    }
  `;

  // 构造获取可用奖励的Cadence脚本
  const rewardsScript = `
    import FlowIDStaking from 0xFlowIDStaking

    pub fun main(user: Address): UFix64 {
      return FlowIDStaking.getRewardsAvailable(user)
    }
  `;

  // 执行脚本获取数据
  const delegationInfo = await fcl.query({
    cadence: delegationScript,
    args: (arg, t) => [arg(userId, t.Address)],
  });

  const availableRewards = await fcl.query({
    cadence: rewardsScript,
    args: (arg, t) => [arg(userId, t.Address)],
  });

  return {
    delegation: delegationInfo,
    availableRewards: availableRewards.toString(),
  };
}

// 调用示例
getUserStakingData("0x1234567890abcdef")
  .then(data => console.log("用户质押数据:", data))
  .catch(err => console.error("获取失败:", err));

Python 实现（直接调用Flow RPC） #

无需依赖SDK，直接通过HTTP请求调用Flow的REST API执行Cadence脚本：

import requests
import json

def get_user_staking_data(user_id: str, is_mainnet: bool = True):
    # 配置网络参数
    if is_mainnet:
        rpc_url = "https://rest-mainnet.onflow.org/v1/scripts"
        staking_contract = "0x8624b52f9ddcd04a"
    else:
        rpc_url = "https://rest-testnet.onflow.org/v1/scripts"
        staking_contract = "0x7e60df042a9c0868"

    # 获取委托信息的Cadence脚本
    delegation_script = f'''
        import FlowIDStaking from {staking_contract}
        pub fun main(user: Address): FlowIDStaking.DelegationInfo? {{
          return FlowIDStaking.getDelegationInfo(user)
        }}
    '''

    # 获取可用奖励的Cadence脚本
    rewards_script = f'''
        import FlowIDStaking from {staking_contract}
        pub fun main(user: Address): UFix64 {{
          return FlowIDStaking.getRewardsAvailable(user)
        }}
    '''

    def execute_script(script: str):
        payload = {
            "script": bytes(script, "utf-8").hex(),
            "arguments": [
                {
                    "type": "Address",
                    "value": user_id
                }
            ]
        }
        headers = {"Content-Type": "application/json"}
        response = requests.post(rpc_url, data=json.dumps(payload), headers=headers)
        return response.json()

    # 执行两个脚本
    delegation_result = execute_script(delegation_script)
    rewards_result = execute_script(rewards_script)

    return {
        "delegation": delegation_result.get("value"),
        "available_rewards": rewards_result.get("value")
    }

# 调用示例
if __name__ == "__main__":
    data = get_user_staking_data("0x1234567890abcdef")
    print("用户质押数据:", data)

关键说明 #

• user_id 需要传入标准的Flow地址（格式如 0x1234567890abcdef）
• 委托信息包含委托金额、节点ID、委托状态等字段，具体结构可参考FlowIDStaking合约的DelegationInfo结构体定义
• getRewardsAvailable 获取的是用户当前可领取的奖励总额，已领取的奖励可通过调用getRewardsClaimed方法获取

内容的提问来源于stack exchange，提问作者Naman Thaker