//express is the framework we're going to use to handle requests
const express = require('express');
//Create a new instance of express
const app = express();
const FormData = require("form-data");
const bodyParser = require("body-parser");
const http = require('http');
const async = require('async');
//This allows parsing of the body of POST requests, that are encoded in JSON
app.use(bodyParser.json());
var router = express.Router();
//AccuWeather API key
const weatherKey = process.env.WEATHER_KEY_TWO;
cityCode = ""; //City code
cityName = "";
//Current Conditions Vars
var ccWeatherText = ""; //Text for weather at location
var ccTemp = 0; //Degrees Farenheit
var ccIcon = 0; //weather icon number https://developer.accuweather.com/weather-icons
var ccURL = "test"; //URL for get
var hourlyData = [];
var fiveDayData = [];
router.post('/', (req, res) => {
let lat = req.body['lat'];
let lon = req.body['lon'];
var latLongCityCodeURL = ("http://dataservice.accuweather.com/locations/v1/cities/geoposition/search?apikey=" + weatherKey + "&q=" + lat + "," + lon);
//Get city code
const httpGet = url => {
return new Promise((resolve, reject) => {
http.get(url, res => {
let body = '';
res.on('data', chunk => body += chunk);
res.on('end', () => {
try {
body = JSON.parse(body);
} catch (err) {
reject(new Error(err));
}
resolve({
code: body.Key,
name: body.EnglishName
});
});
}).on('error', reject);
});
};
//Current Conditions
const ccGet = url => {
return new Promise((resolve, reject) => {
http.get(url, res => {
let body = '';
res.on('data', chunk => body += chunk);
res.on('end', () => {
try {
body = JSON.parse(body);
} catch (err) {
reject(new Error(err));
}
resolve({
text: body[0].WeatherText,
temp: body[0].Temperature.Imperial.Value,
icon: body[0].WeatherIcon
});
});
}).on('error', reject);
});
};
//12 hour
const twelveGet = url => {
return new Promise((resolve, reject) => {
http.get(url, res => {
let body = '';
res.on('data', chunk => body += chunk);
res.on('end', () => {
try {
body = JSON.parse(body);
} catch (err) {
reject(new Error(err));
}
resolve({
body: body
});
});
}).on('error', reject);
});
};
//5 day
const fiveGet = url => {
return new Promise((resolve, reject) => {
http.get(url, res => {
let body = '';
res.on('data', chunk => body += chunk);
res.on('end', () => {
try {
body = JSON.parse(body);
} catch (err) {
reject(new Error(err));
}
resolve({
body: body
});
});
}).on('error', reject);
});
};
//Get city code from lat lon
httpGet(latLongCityCodeURL).then(data => {
cityCode = data.code;
cityName = data.name;
ccURL = ("http://dataservice.accuweather.com/currentconditions/v1/" + cityCode + "?apikey=" + weatherKey);
twelveURL = ("http://dataservice.accuweather.com/forecasts/v1/hourly/12hour/" + cityCode + "?apikey=" + weatherKey);
fiveURL = ("http://dataservice.accuweather.com/forecasts/v1/daily/5day/" + cityCode + "?apikey=" + weatherKey);
//Get Current Conditions
ccGet(ccURL).then(dataCC => {
ccTemp = dataCC.temp;
ccWeatherText = dataCC.text;
ccIcon = dataCC.icon;
//Get 12 hour forecast
twelveGet(twelveURL).then(dataTwelve => {
//Generate hourly data
for (i = 0; i < dataTwelve.length; i++) {
hourlyData[i] = {
time: dataTwelve[i].EpochDateTime,
temp: dataTwelve[i].Temperature.Value,
text: dataTwelve[i].IconPhrase,
icon: dataTwelve[i].WeatherIcon
};
}
console.log("Hourly Data: " + hourlyData);
}).catch(err => console.log(err));
fiveGet(fiveURL).then(dataFive => {
//Generate five day data
for (i = 0; i < dataFive.length; i++) {
fiveDayData[i] = {
time: dataFive[i].EpochDate,
min: dataFive[i].Temperature.Minimum.Value,
max: dataFive[i].Temperature.Maximum.Value,
iconDay: dataFive[i].Day.Icon,
iconNight: dataFive[i].Night.Icon,
dayPhrase: dataFive[i].Day.IconPhrase,
nightPhrase: dataFive[i].Night.IconPhrase
};
console.log("5 Day Data:" + fiveDayData);
}
res.send({
success: true,
cityName: cityName,
cityCode: cityCode,
currentConditions: {
temp: ccTemp,
icon: ccIcon,
text: ccWeatherText
},
hourlyData: hourlyData,
fiveDayData: fiveDayData
});
}).catch(err => console.log(err));
}).catch(err => console.log(err));
}).catch(err => console.log('Got error ', err));
});
module.exports = router;
好的，我现在正在NodeJS中创建一个POST方法的端点，它获取纬度和经度的参数。当它获得那些它调用Accuweather的API。我得到了所有精确的工作并返回了正确的结果，但随后我将该代码剪切并粘贴到我的POST方法router.post...中，现在它还没有工作。我知道这是一个ASYNC问题，我只是真的迷失了异步，因为我在router.post里面有3或4个嵌套的异步调用，这是另一个异步调用。所以我认为有一些方法可以将router.post包装到自己的异步调用中，它会在返回结果之前等待天气调用？
我的最终目标：为了让用户发送带有lat和lon的POST，我的代码会执行所有天气调用，并返回POST的数据。
答案 0 :(得分：0)
您要做的是promise chaining：
new Promise(function(resolve, reject) {
setTimeout(() => resolve(1), 1000); // (*)
}).then(function(result) { // (**)
alert(result); // 1
return result * 2;
}).then(function(result) { // (***)
alert(result); // 2
return result * 2;
}).then(function(result) {
alert(result); // 4
return result * 2;
});