javascript - 从 JSON 字符串拆分有效负载

Question

我通过 WebSocket 收到这些巨大的字符串:

[
  "BTC-31DEC21-100000-P",
  "{\"data\":{\"bids\":{\"0.01\":{\"price\":0.01,\"volume\":66.2,\"exchange\":\"DER\"},\"5.0E-4\":{\"price\":5.0E-4,\"volume\":1.1,\"exchange\":\"DER\"},\"0.637\":{\"price\":0.637,\"volume\":8.4,\"exchange\":\"DER\"}},\"asks\":{\"0.664\":{\"price\":0.664,\"volume\":8.4,\"exchange\":\"DER\"}}},\"isMasterFrame\":true}"
]

或者

[
  "BTC-31DEC21-36000-C",
  "{\"data\":[{\"price\":0.422,\"volume\":8.4,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.423,\"volume\":0.0,\"exchange\":\"DER\",\"side\":\"ASKS\"}],\"isMasterFrame\":false}"
]

或者

[
  "BTC-31DEC21-60000-P",
  "{\"data\":[{\"price\":0.105,\"volume\":0.0,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.1055,\"volume\":28.7,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.106,\"volume\":7.6,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.1065,\"volume\":43.0,\"exchange\":\"DER\",\"side\":\"ASKS\"}],\"isMasterFrame\":false}"
]

我想查看 isMasterFrame

let payload = JSON.parse(messageString[1]);

if (payload.hasOwnProperty("isMasterFrame")) {
 for (let i = 0; i < payload.pairs.length; i++) {
   let currentPair = payload.data[i]
      currentPair = currentPair.replace(/\0/g, ''); //Remove null chars
       if (currentPair.toUpperCase() != 'KILL') {
           props.onAddAvailablePair(currentPair);
        }
       }
      } else {
             // print some output with payload which holds "isMasterFrame":false
     }

当我运行代码时出现错误:

TypeError: Cannot read properties of undefined (reading 'length')

一对内部数据: {\"price\":0.423,\"volume\":0.0,\"exchange\":\"DER\",\"side\":\"ASKS\"}应该被拆分并一一插入循环
你知道我该如何解决这个问题吗？

Answer 1

当 isMasterFrame 时，您的数据具有不同的结构是不同的。您有 bids 的对象和 asks在 isMasterFrame 时的数据中是 true而 isMasterFrame 时是一个数组是假的。

const data1 = [
    "BTC-31DEC21-100000-P",
    "{\"data\":{\"bids\":{\"0.01\":{\"price\":0.01,\"volume\":66.2,\"exchange\":\"DER\"},\"5.0E-4\":{\"price\":5.0E-4,\"volume\":1.1,\"exchange\":\"DER\"},\"0.637\":{\"price\":0.637,\"volume\":8.4,\"exchange\":\"DER\"}},\"asks\":{\"0.664\":{\"price\":0.664,\"volume\":8.4,\"exchange\":\"DER\"}}},\"isMasterFrame\":true}"
  ],
  data2 = [
    "BTC-31DEC21-36000-C",
    "{\"data\":[{\"price\":0.422,\"volume\":8.4,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.423,\"volume\":0.0,\"exchange\":\"DER\",\"side\":\"ASKS\"}],\"isMasterFrame\":false}"
  ]
data3 = [
  "BTC-31DEC21-60000-P",
  "{\"data\":[{\"price\":0.105,\"volume\":0.0,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.1055,\"volume\":28.7,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.106,\"volume\":7.6,\"exchange\":\"DER\",\"side\":\"ASKS\"},{\"price\":0.1065,\"volume\":43.0,\"exchange\":\"DER\",\"side\":\"ASKS\"}],\"isMasterFrame\":false}"
];

const formatData = (data) => {
  return data.reduce((r, o) => {
      Object.entries(o).forEach(([k,v]) => {
        r[k] ??= [];
        r[k].push(v);
      });
      return r;
    }, {})
}

[data1, data2, data3].forEach(data => {
  const o = JSON.parse(data[1]);
  if(o.isMasterFrame) {
    const result = formatData(Object.values(o.data.bids));
    console.log(result);
  } else {
    const result = formatData(o.data);
    console.log(result);
  }
});