我有一个用Axios实现的中间件:它调用2或3个路由,前2个路由函数使用res.locals.someVariable和next()函数返回单个值,例如:
exports.getReservierungenByMonth = function(req,res,next) {
Produkt.aggregate([
{
"$unwind":"$DemonstratorWerte"
},
{
"$match": {"DemonstratorWerte.Demonstrator" : +req.params.demo_id/*, "ProduktReserviert.Status": false*/}
},
.......
{
"$addFields": {
"Monat": {
"$let": {
"vars": {
"monthsInStrings": [, "Januar", "Februar", "Maerz", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember"]
},
"in": {
"$arrayElemAt": ['$$monthsInStrings','$Monat']
}
}
}
}
}
]).exec(function(err, prod) {
if (err) {
res.json(err);
}
else {
res.locals.reservierungen = reservierungenArray;
//res.locals.reservierungen = prod;
next();
}
})//.then((res) => res.json())
};
然后,来自axios的第三个路由器链接使用这些res.locals变量来查询和聚合一些数据,例如:
exports.getStornierungenReservierungen = function(req,res,next) {
stornierungen = res.locals.stornierungen;
reservierungen = res.locals.reservierungen;
Produkt.aggregate([
{
$project: {
"Alle": { $concatArrays: [ stornierungen, reservierungen ]}
}
},
{...}
然后,我的第三个路由器链接返回前两个res.locals值的聚合数据,包括最后一个路由函数:
router.route('/Middleware/sdasdhgrt/:demo_id').get(function(req,res,next) {
axios.all([
axios.get(`http://localhost:2323/D/L4C/a/${req.params.demo_id}`),
axios.get(`http://localhost:23325/D/Ls/b/${req.params.demo_id}`),
//axios.get(`http://localhost:53355/4Z/L4C/3/${req.params.demo_id}`)--->> needs the res.locals values!
])
.then(axios.spread(function (result1,result2,result3) {
res.send({result1,result2});
res.write(JSON.stringify({
result1, result2, result3
}));
//console.log('Result1: ', result1.data);
//console.log('Result2: ', result2.data);
//console.log('Result3: ', result3.data);
})).catch(error => {
console.log(error);
});
});
我现在的问题是:如何使用axios将res.locals值从2个路由器链接传递到第三个链接?在Express中,我只是通过使用next()函数来做到这一点......
在这段代码中:
axios.all([
axios.get(`http://localhost:2323/D/L4C/a/${req.params.demo_id}`),
axios.get(`http://localhost:23325/D/Ls/b/${req.params.demo_id}`),
//axios.get(`http://localhost:53355/4Z/L4C/3/${req.params.demo_id}`)--->> needs the res.locals values!
])
难道你不能只使用前两个请求作为axios.all()
的一部分,然后使用.then(callback)
发出第三个请求吗?所以类似于:
axios.all([
axios.get(`http://localhost:2323/D/L4C/a/${req.params.demo_id}`),
axios.get(`http://localhost:23325/D/Ls/b/${req.params.demo_id}`),
])
.then((done) => {
axios.get(`http://localhost:53355/4Z/L4C/3/${req.params.demo_id}`)
done();
})
.then((done) => {
//the rest of your code
done();
})
编辑:
老实说,我也只是使用async / await有点像这样(可能会遗漏一些东西,我根本没有测试过这个,只是写出了我的头脑):
try {
let dataToUse = [], promises = [];
let now = new moment();
promises.push(axios(`http://localhost:2323/D/L4C/a/${req.params.demo_id}`));
promises.push(axios(`http://localhost:23325/D/Ls/b/${req.params.demo_id}`));
const responses = await Promise.all(promises);
dataToUse = responses.map(response => response.data);
//make third request with data
axios.get(`http://localhost:53355/4Z/L4C/3/${dataToUse.parameter}`);
// Send your data with res.send();
} catch (e) {
res.status(400).send({
//error info
});
}
干杯,