尝试确保请求在呈现页面之前已完成
应用程序概述 - 使用代码提交、发出请求、填充结果页面
//索引.js
var response = require('./requestMapping')
// home search page
exports.index = function(req, res){
res.render('index', { stationDisplay: response.station_id, test: 'rob' });
};
**//post from form to call METAR service
exports.post =('/', function(req, res, next) {
response.getMETAR(req.body.query,function(){
res.render('results', {
stationDisplay: response.station_id,
test: 'rob'
});
});
})**
//索引.ejs
<!DOCTYPE html>
<html>
<head>
<title><%= stationDisplay %></title>
<link rel='stylesheet' href='/stylesheets/style.css' />
</head>
<body>
<h1>Enter ICAO code to get the latest METAR</h1>
<form method="post" action="/">
<input type="text" name="query">
<input type="submit">
</form>
</body>
</html>
调用Web服务的模块 - requestMapping.js
/**
* @author robertbrock
*/
//Webservice XML
function getMETAR(ICAO){
var request = require('request');
request('http://weather.aero/dataserver_current/httpparam?datasource=metars&requestType=retrieve&format=xml&mostRecentForEachStation=constraint&hoursBeforeNow=24&stationString='+ICAO, function(error, response, body){
if (!error && response.statusCode == 200) {
var XmlDocument = require('xmldoc').XmlDocument;
var results = new XmlDocument(body);
console.log(body)
console.log(ICAO)
exports.station_id = results.valueWithPath("data.METAR.station_id");
//etc.
}
})
}
exports.getMETAR =getMETAR;
最佳答案
我看不出您的 getMETAR 函数实际上采用了回调函数？我希望它是:
function getMETAR(ICAO, callback) {
// Do your work
var station_id = results.valueWithPath("data.METAR.station_id");
callback(null, station_id); // It's common to use the first arg of the callback if an error has occurred
}
然后调用该函数的代码可以像这样使用它:
app.post('/', function(req, res) {
response.getMETAR(req.body.query, function(err, station_id) {
res.render('results', {stationDisplay: station_id, test: 'rob'};
});
});
需要一些时间来适应异步编程以及回调的工作方式，但是一旦您完成了几次，您就会掌握它的窍门。
关于node.js - 努力让回调工作express.js，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15724046/