关于javascript：Express.js res.render()和res.redirect()

Express.js res.render() and res.redirect()

我的快速应用程序中有一条路线，应该执行以下操作：

从外部获取一些数据(确定)
显示带有socket.io的HTML页面以侦听消息(确定)
执行一些计算，这需要很长时间
每完成一个操作，就通过socket.io发送一条消息(确定)
完成所有计算后，显示结果页面(问题)

因此，我的代码的简化版本是：

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module.exports = function(io) { // This is so I can use socket.io inside the route
var express = require('express');
var router = express.Router();

[... and other required]

router.post('/', function(req, res, next) {
res.render('loading'); // This renders the template which holds accepts and renders socket.io messages
pefromCalculaton();
sendSocketIOMessage();
session.data = resultData; // I get the result of all calculations and put that in the session. It's a quick fix, don't judge, I've got no presistancy in my project as for now...
res.redirect('results'); // And here I'd like to go to the other route, which will display the data, getting it from the session.
});
return router;
}

因为这行不通，所以我可能试图在这里做一些真正愚蠢的事情。但是我真正想做的是：

执行计算
在执行计算时，使用套接字更新进度
计算完成后，渲染一个模板，显示所有结果。

好吧，我的朋友，正如您所知，一个请求中的一个不能发送两个响应。所以这是您需要做的。

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module.exports = function(io) { // This is so I can use socket.io inside the route
var express = require('express');
var router = express.Router();

[... and other required]

router.post('/', function(req, res, next) {
var taskId = (new Date()).getTime(); //timestamp to get unique task id.
res.render('loading');
startCalculations(function(progressIndicator){ //progress callback
io.emit('progress',progressIndicator);
},function(result){ // Finish callback
session[taskId] = result;
io.emit('finish',{ taskid: taskId });
});
});

router.get('/result:taskId', function(req, res, next) {
var result = session[req.params.taskId];
if(!result)
{
//Result already consumed!
res.render('expired');
return;
}
delete session[req.params.taskId];
res.render('result', {result: result});
});

//progress callback will be called when we want to report progress
//done callback indicates our results are ready.
function startCalculations(progress, done){
//This is just a stupid piece of code, just to emulate loading.
//Your awesome async code will replace this
//In your case it will not be a loop and there will be a callback
//To signal finish.
var result = 0;
for(i = 0; i < 100; i++)
{
result = result + i;
//Simulate progress
progress(i);
}
//Simulate finish -- result has 0 to 99 all added up ;)
done(result);

}

return router;
}

现在在html前面您可以拥有...

this is how your loading view would look like.

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希望这是有道理的，对您有帮助...

让我知道您是否还有其他需要。

玩得开心！