http请求函数不会返回结果 [英] http request function won't return result

问题描述

我正在使用Express.js设置服务器，并且希望对'/'发出'GET'请求以返回函数的结果.该函数正在从新闻API发出获取请求.当我调用"/"时，该函数被触发，结果(故事")被记录在控制台中，但是对"/""GET"请求的响应中没有任何发送.我尝试将"return"语句放在几个不同的位置，但仍然无法正常工作……任何想法将不胜感激！谢谢！

I am setting up a server with Express.js and I want a 'GET' request to '/' to return the results of a function. The function is making an get request from a news API. When I make the call to '/', the function is being triggered, and the results ('stories') is being logged in the console, but nothing is being sent in the response to the '/' 'GET' request. I have tried putting the 'return' statement in a few different places and it still doesn't work... any idea would be hugely appreciated! thanks!

app.js

var express = require('express');
var app = express();
var stories = require('./stories.js')


app.get('/', function(req, res){
  var returnedStories = stories.searchStories();
  res.send(returnedStories);
})

var server = app.listen(3000, function () {

  var host = server.address().address;
  var port = server.address().port;

  console.log('going live on port', host, port);

});

stories.js

stories.js

var request = require('request');




function searchStories(){
  var stories = '';
  request({
    url:'http://content.guardianapis.com/search?q=christopher%20nolan&api-key=3th9f3egk2ksgp2hr862m4c9',
    json: true},
     function (error, response, body) {
    if (!error && response.statusCode == 200) {
      console.log(body.response.results) ;
      stories = body.response.results;
      return stories;
    }
  })
};


module.exports = {
  searchStories: searchStories
  }

推荐答案

这是一个异步问题.当您执行 res.send 时， searchStories 函数未完成.

It's an asynchronous problem. searchStories function is not finish when you execute res.send.

您可以使用promise( https://www.promisejs.org )或回调.我会给你一个回调的例子.

You can use promise (https://www.promisejs.org) or a callback. I'll give to you an example with callback.

stories.js

stories.js

module.exports.searchStories = function (callback) {
  var stories;

  // GET your stories then execute the callback with the result

  stories = [
    {id: 1, name: "story 1"},
    {id: 2, name: "story 2"}
  ];

  callback(stories);
}

app.js

var express = require('express');
var app = express();
var stories = require('./stories.js')


app.get('/', function(req, res){
  stories.searchStories(function (returnedStories) {
    res.send(returnedStories);
  });
})

var server = app.listen(3000, function () {

  var host = server.address().address;
  var port = server.address().port;

  console.log('going live on port', host, port);

});

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