我必须使用请求模块在 NodeJs 的服务器端进行多次序列化调用，并且RxJs 可观察
我有一系列网址地址，如['www.google.com'，'facebook.com'] 当我发出调用请求时，服务器在事件循环中变得繁忙。我想知道我的最后一个 url 调用何时得到响应，以便我可以将响应发送到前端 这是我到目前为止的代码
const foo = Observable.create(function (observer) {
res.writeHeader(200, { "Content-Type": "text/html" });
var str = '<html><head></head><body><h1> Following are the responses: </h1><ul>'
res.write(str);
let count = 0;
addressesArray.forEach(function (element, i) {
observer.next(element);
if (some Condition) {
console.log('here i want to call complete when I get last response')
// observer.complete();
}
})
})
这是我的订阅功能
const subscription = foo.subscribe({
next : addres =>
{
request(addres , function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(response)
}
if (typeof response === "undefined" || typeof body === "undefined") {
console.log('No resp')
}
})
},
complete:()=>{console.log('done')}
})
您可以使用from运算符从addressesArray开始您的 Observable，当它到达数组末尾时，它将自行完成
from(addressesArray).pipe(
mergeMap(address => {
return new Observable(obs => {
request(address, function (error, response, body) {
if (!error && response.statusCode == 200)
obs.next(response)
else
obs.next('')
obs.complete()
})
})
}),
reduce((allResponses, response) => {
return allResponse += '<li>' + response + '<li/>'
}, ''),
tap(allResponses => {
res.writeHeader(200, { "Content-Type": "text/html" });
var str = '<html><head></head><body><h1> Following are the responses: </h1><ul>'
res.write(allResponses + '</ul')
res.end()
})
).subscribe()