如何从Node.js http获取请求中获取数据 [英] How to get data out of a Node.js http get request

问题描述

我试图让我的函数返回http get请求，但是，无论我做什么，它似乎都迷失在范围中。我退出了新的Node.js，所以任何帮助将不胜感激

  function getData（）{
 var http = require（'http'）; 
 var str =''; 
 
 var options = {
 host：'www.random.org'，
 path：'/ integer /？num = 1& min = 1& max = 10& col = 1& base = 10& format = plain& rnd = new'
}; 
 
 callback = function（response）{
 
 response.on（'data'，function（chunk）{
 str + = chunk; 
} ）; 
 $ b response.on（'end'，function（）{
 console.log（str）; 
}）; 
 
 // return str; 
} 
 
 var req = http.request（options，callback）.end（）; 
 
 //这些只是返回未定义的和空的
 console.log（req.data）; 
 console.log（str）; 
 
  

解决方案

当然， code> undefined ：您在请求完成之前记录日志。问题不在于作用域，而是异步。

http.request 这就是为什么它需要回调参数。在回调（你传递给 response.end ）的回调中做你必须做的事情：

  callback = function（response）{
 
 response.on（'data'，function（chunk）{
 str + = chunk; 
}） ; 
 $ b response.on（'end'，function（）{
 console.log（req.data）; 
 console.log（str）; 
 //你的代码在这里，如果你想使用结果！
}）; 
} 
 
 var req = http.request（options，callback）.end（）; 
  

I'm trying to get my function to return the http get request, however, whatever I do it seems to get lost in the ?scope?. I'm quit new to Node.js so any help would be appreciated

function getData(){
  var http = require('http');
  var str = '';

  var options = {
        host: 'www.random.org',
        path: '/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
  };

  callback = function(response) {

        response.on('data', function (chunk) {
              str += chunk;
        });

        response.on('end', function () {
              console.log(str);
        });

        //return str;
  }

  var req = http.request(options, callback).end();

  // These just return undefined and empty
  console.log(req.data);
  console.log(str);
}

解决方案

Of course your logs return undefined : you log before the request is done. The problem isn't scope but asynchronicity.

http.request is asynchronous, that's why it takes a callback as parameter. Do what you have to do in the callback (the one you pass to response.end):

callback = function(response) {

  response.on('data', function (chunk) {
    str += chunk;
  });

  response.on('end', function () {
    console.log(req.data);
    console.log(str);
    // your code here if you want to use the results !
  });
}

var req = http.request(options, callback).end();

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