node.js - 处理异步http调用 Node js

Question

我在 Node js 服务器上有一个 RESTish api。当它收到一个 GET 请求时，它会调用一个函数，然后该函数将调用另一个服务器的 get 函数。代码如下所示:

var server = http.createServer(function(request, response) {
    console.log("YEAHHH! ", request.method);
    var string='';
    // Inside a request handler method
    if (request.method == "OPTIONS") {
        console.log("options");
        // Add headers to response and send
        //response.writeHead(statusCode, responseHeaders);
        response.writeHead(success,responseHeaders);
        response.end();
    }
    if(request.method == "GET") {
        string = soso();
    }

    console.log("*******", string);
    response.writeHead(success,responseHeaders);
    response.end(string);
});

soso() 是对其他服务器的调用。问题是我想在 soso() 函数完成之前发送它的响应，所以我得到的只是一个空字符串。

我该如何解决这个问题？

我确定这是重复的，但无法完全找到我要找的东西。所以，任何帮助表示赞赏。

编辑

搜搜功能代码:

var soso = function () {
    console.log("this is being called");
    var options = {...}

    var req = https.get( options, function(res)  {
        var str = '';
        res.on('data', function ( chunk ) {
            str += chunk;
        })

        res.on('end', function () {
            console.log ( "str is: ", str );
            string = str;
        })

        req.end();
        console.log(res.statusCode);
        console.log(responseHeaders);
    });

}

Answer 1

你可以尝试这样的事情，我不确定。我没有测试过这个。在soso函数中传入response对象，get请求结束后使用response.end(string);

var server = http.createServer(function(request, response) {
        console.log("YEAHHH! ", request.method);
        var string='';
        // Inside a request handler method
        if (request.method == "OPTIONS") {
            console.log("options");
            // Add headers to response and send
            //response.writeHead(statusCode, responseHeaders);
            response.writeHead(success,responseHeaders);
            response.end();
        }
        if(request.method == "GET") {
            string = soso(response);   //send response object as argument
        } else {
     console.log("*******", string);
        response.writeHead(success,responseHeaders);
        response.end(string);
    }


    });

搜搜功能

var soso = fuction(response){ // we pass the response object in soso function
    console.log("this is being called");
        var options = {...}

        var req = https.get( options, function(res)  {
            var str = '';
            res.on('data', function ( chunk ) {
                str += chunk;
            })

            res.on('end', function () {
                console.log ( "str is: ", str );
                string = str;
            })

            req.end();
     response.writeHead(success,responseHeaders);  
        response.end(string);
            console.log(res.statusCode);
            console.log(responseHeaders);
        });

}