Question

运行此IBM Cloud Function时遇到一些麻烦：

    /**
  *
  * main() will be run when you invoke this action
  *
  * @param Cloud Functions actions accept a single parameter, which must be a JSON object.
  *
  * @return The output of this action, which must be a JSON object.
  *
  */

function main(params) {

    const https = require('https');

https.get('https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY', (resp) => {
  let data = '';

  // A chunk of data has been recieved.
  resp.on('data', (chunk) => {
    data += chunk;
  });

  // The whole response has been received. Print out the result.
  resp.on('end', () => {
    console.log(JSON.parse(data).explanation);
  });

}).on("error", (err) => {
  console.log("Error: " + err.message);
});

}

我的问题是，此函数的第一次调用（至少第一个3-4）没有输出。后续调用正常运行，并且日志正确显示。我该如何解决这种不可预测的行为？我当然希望在第一次调用此函数时检索我的数据。谢谢。

Answer 1

Node.js使用非阻塞异步编程模型。此main函数在HTTP响应可用之前返回。

返回承诺将使您能够等待HTTP响应。

function main(params) {
  return new Promise((resolve, reject) => {
    const https = require('https');

    https.get('https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY', (resp) => {
      let data = '';

      // A chunk of data has been recieved.
      resp.on('data', (chunk) => {
        data += chunk;
      });

      // The whole response has been received. Print out the result.
      resp.on('end', () => {
        const explanation = JSON.parse(data).explanation
        console.log(explanation);

        resolve({ explanation })
      });

    }).on("error", (err) => {
      console.log("Error: " + err.message);
      reject({ error: err.message })
    });

  })
}

Answer 2

要检查的另外两件事：

确保将.json附加到端点

示例：https://<ibm-domain>/api/v1/web/<username>/default/<function>.json

请确保在侧边栏Enable as Web Action中选择Endpoints。

此外，您应该能够返回async主函数来代替Promise对象。

async function main(params) {
  try {
    // some `await` function
  } catch (e) {
    // catch `await` errors
  }
}

module.exports = main;

IBM Cloud Function不产生任何输出

2 个答案: