我正在尝试这样做，以便我可以将我的trend变量从其函数传递到我的Pug模板的渲染器，我似乎无法做到。
var express = require('express');
var router = express.Router();
var googleTrends = require('google-trends-api');
var auth = require('http-auth');
var ustrends;
var uktrends;
const Console = require('console').Console;
var basic = auth.basic({
realm: "Web."
}, function (username, password, callback) { // Custom authentication method.
callback(username === "user" && password === "pass");
}
);
var find = ',';
var regex = new RegExp(find, 'g');
googleTrends.hotTrends('US').then(function(trends){
ustrends = trends
});
googleTrends.hotTrends('EU').then(function(trends1) {
uktrends = trends1
});
console.log(ustrends);
/* GET home page. */
router.get('/', auth.connect(basic), function(req, res, next) {
res.render('index', {trends: ustrends.toString().replace(regex, ", "), trends1: uktrends.toString().replace(regex, ", "), title: 'Trends in the U.S & U.K'});
});
module.exports = router;
正如您所看到的，我正在尝试将“ustrends”和“uktrends”变量传递给渲染器。任何帮助表示赞赏。
答案 0 :(得分：1)
请记住using System;
using System.Timers;
public class Example
{
private static System.Timers.Timer aTimer;
public static void Main()
{
SetTimer();
Console.WriteLine("\nPress the Enter key to exit the application...\n");
Console.WriteLine("The application started at {0:HH:mm:ss.fff}", DateTime.Now);
Console.ReadLine();
aTimer.Stop();
aTimer.Dispose();
Console.WriteLine("Terminating the application...");
}
private static void SetTimer()
{
// Create a timer with a two second interval.
aTimer = new System.Timers.Timer(2000);
// Hook up the Elapsed event for the timer.
aTimer.Elapsed += OnTimedEvent;
aTimer.AutoReset = true;
aTimer.Enabled = true;
}
private static void OnTimedEvent(Object source, ElapsedEventArgs e)
{
Console.WriteLine("The Elapsed event was raised at {0:HH:mm:ss.fff}",
e.SignalTime);
}
}
// The example displays output like the following:
// Press the Enter key to exit the application...
//
// The application started at 09:40:29.068
// The Elapsed event was raised at 09:40:31.084
// The Elapsed event was raised at 09:40:33.100
// The Elapsed event was raised at 09:40:35.100
// The Elapsed event was raised at 09:40:37.116
// The Elapsed event was raised at 09:40:39.116
// The Elapsed event was raised at 09:40:41.117
// The Elapsed event was raised at 09:40:43.132
// The Elapsed event was raised at 09:40:45.133
// The Elapsed event was raised at 09:40:47.148
//
// Terminating the application...
will return a promise，因为它会从Google的API获得结果。由于渲染器位于其中hotTrends和ustrends设置为值的回调之外，因此无法保证在调用渲染器之前设置这些值。
你可以使用几个嵌套的回调，但这会导致一些代码被推到相当远的位置;我推荐async库，它有一个名为series的函数，它允许你传入1）要按顺序执行的函数数组，以及2）在函数有执行后执行的回调。已完成，如果有一个错误，并且函数的结果作为参数，则会收到错误。在下面的代码段中，trend API会在调用渲染器之前返回结果：
uktrends