以下是我在 Node.js 中尝试执行的操作。 Rest API 将城市名称作为输入。我正在尝试使用输入城市的地理编码 API 获取纬度和经度。then,使用纬度和经度,我尝试使用另一个 API 获取最近城市的列表。then,对于所有这些城市,我正在收到天气预报,then对于这些城市,我会获取是否有水,并将其作为 JSON 返回。
正如你所看到的,有很多then本练习的目标是避免嵌套回调。
我正在使用 async/await ,它应该消除了嵌套的 then 函数。但我没有看到其他方法可以做到这一点。完整的代码片段如下。我试图修复的丑陋部分是 requester.makeRequest()
以下只是必要代码的片段,而不是完整的工作代码。任何关于如何解决这个问题的帮助将不胜感激。
app.get('/search', function(req, res, next) {
const requester = {
lastRequest: new Date(),
makeRequest: async function(url) {
const response = await fetch(url);
const json = await response.json();
return json;
}
};
requester.makeRequest(geocode_url +`?locate=${req.query.q}&json=1`
+ geocode_token)
.then(function(city){
var final_result = []
var lat = city.latt;
var long = city.longt;
// request to get list of cities closer to that location,
//takes latitude and longitude as parameters
requester.makeRequest(metaweather_url + '?lattlong='
+ lat + ',' + long)
.then(function(closer_cities) {
var cities_len = closer_cities.length
for(i = 0; i < closer_cities.length; i++) {
woeid = closer_cities[i].woeid
//request to get weather using woeid parameter
requester.makeRequest(woeid_url + woeid)
.then(function(weather) {
var lattlong = weather.latt_long;
requester.makeRequest(onwater_url+ lattlong +
'?access_token=' + water_access_token)
.then(function(onwater) {
var temp = Object.assign(weather, onwater)
final_result.push(temp)
if (final_result.length == cities_len) {
res.status(200).json({error: false,
data: {message: final_result}})
}
})
})
}
})
})
})
我想说你还需要一个
requester.makeRequest(geocode_url +`?locate=${req.query.q}&json=1`
+ geocode_token)
.then(async function(city){
var final_result = []
var lat = city.latt;
var long = city.longt;
// request to get list of cities closer to that location,
//takes latitude and longitude as parameters
closer_cities = await requester.makeRequest(metaweather_url + '?lattlong='+ lat + ',' + long);
var cities_len = closer_cities.length;
for(i = 0; i < closer_cities.length; i++) {
woeid = closer_cities[i].woeid
//request to get weather using woeid parameter
weather = await requester.makeRequest(woeid_url + woeid)
var lattlong = weather.latt_long;
onwater = await awaitrequester.makeRequest(onwater_url+ lattlong + '?access_token=' + water_access_token)
var temp = Object.assign(weather, onwater)
final_result.push(temp)
if (final_result.length == cities_len) {
res.status(200).json({error: false, data: {message: final_result}})
}
}
})
编辑:我真的认为我的答案与您的问题无关,抱歉
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