如何在 NodeJS 中返回来自 function 的 Post 请求的响应？

Question

I have a function in my project that processes most of my API requests (see simplified draft below)

function sendRequest(){

    var reqbody;
    var resp;

    reqbody = unimportantRandomFunction();

    request.post({
        headers: {  'content-type'  : 'application/xml',
                    'accept'        : 'application/xml'},
        url: process.env.APIURL,
        body: reqbody
    }, function(error, response, body){
        resp = convert.xml2js(body, {compact:true});
    });

    return resp;
}

The problem I am facing is that request.post is asynchronous and by the time I get the response, an undifined value has already been returned. I tried experimenting with promises (something I am entirely new to) but obviously I can't place my return in a.then block either because that return will not belong to the sendRequest function (correct me if I'm wrong). Any ideas where I could put my return statement to make it work, that is wait for the value of "resp" to be assigned?

Answer 1

How about this modification? Please think of this as just one of several possible answers.

Promise is used sendRequest() . And the response value is retrieved in the async function. At the following modified script, at first sample() is run. And sendRequest() is run, then the response value is retrieved at console.log(res) .

Modified script:

function sendRequest() {
  return new Promise((resolve, reject) => {
    var reqbody;
    var resp;

    reqbody = unimportantRandomFunction();

    request.post(
      {
        headers: {
          "content-type": "application/xml",
          accept: "application/xml"
        },
        url: process.env.APIURL,
        body: reqbody
      },
      function(error, response, body) {
        if (error) reject(error);
        resp = convert.xml2js(body, { compact: true });
        resolve(resp);
      }
    );
  });
}

async function sample() {
  const res = await sendRequest().catch(err => console.log(err));
  console.log(res);
}

sample();  // This function is run.

References:

• Promise
• async function

If I misunderstood your question and this was not the direction you want, I apologize.