问题
I am using express-session to prevent variable from being global for more than one client, so they don't get tangled up. Here is my entire NEW express code:
const path = require("path");
const bodyParser = require("body-parser");
const express = require("express");
const app = express();
const session = require('express-session');
app.use(session({
secret: process.env.SECRET,
name: 'lastQuestion',
cookie: {
sameSite: "lax",
secure: true,
httpOnly: true
}
}));
app.use(bodyParser.urlencoded({ extended: false }));
app.set('views', __dirname + '/public');
app.engine('html', require('ejs').renderFile);
app.set('view engine', 'html');
app.get('/', (req, res) => {
req.session.lastQuestion = generateQuestion();
res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: true});
});
app.listen(process.env.PORT);
app.post("/prompt", (req, res) => {
console.log("New prompt: " + req.body.inputOne);
req.session.lastQuestion = generateQuestion();
res.render(__dirname + '/public/index.html', {response: evaluatePrompt(req.body.inputOne.toLowerCase()), question: req.session.lastQuestion, instructions: false});
});
app.post("/answer", (req, res) => {
console.log("New answer: " + req.body.inputTwo);
console.log(req.body.question + req.session.lastQuestion);
analyzeConversationAndWriteToLTM(req.session.lastQuestion, req.body.inputTwo);
//Line above this /\ /\ /\ /\
req.session.lastQuestion = generateQuestion();
res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: false});
});
app.post("/regenerate", (req, res) => {
req.session.lastQuestion = generateQuestion();
res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: false});
});
entire OLD code:
3 const bodyParser = require("body-parser");
1414 const express = require("express");
1515 const app = express();
1616 const session = require('express-session');
17 - var lastQuestion;
1817
1918 app.use(session({
2019 secret: process.env.SECRET,
21 - name: 'session',
20 + name: 'lastQuestion',
2221 cookie: {
23 - sameSite: false,
22 + sameSite: "lax",
2423 secure: true,
2524 httpOnly: true
2625 }
2726 }));
@@ -31,34 +30,31 @@
3130 app.engine('html', require('ejs').renderFile);
3231 app.set('view engine', 'html');
3332
3433 app.get('/', (req, res) => {
35 - res.sendFile(__dirname + '/public/index.html');
36 - lastQuestion = generateQuestion();
34 + req.session.lastQuestion = generateQuestion();
35 + res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: true});
37 - res.render(__dirname + '/public/index.html', {response: "Hello!", question: lastQuestion, instructions: true});
3836 });
3937
4038 app.listen(process.env.PORT);
4139
4240 app.post("/prompt", (req, res) => {
4341 console.log("New prompt: " + req.body.inputOne);
44 - res.sendFile(path.join(__dirname + '/public/index.html'));
45 - lastQuestion = generateQuestion();
42 + req.session.lastQuestion = generateQuestion();
43 + res.render(__dirname + '/public/index.html', {response: evaluatePrompt(req.body.inputOne.toLowerCase()), question: req.session.lastQuestion, instructions: false});
46 - //res.render(__dirname + '/public/index.html', {response: evaluatePrompt(req.body.inputOne.toLowerCase()), question: lastQuestion, instructions: false});
4744 });
4845
4946 app.post("/answer", (req, res) => {
5047 console.log("New answer: " + req.body.inputTwo);
51
res.sendFile(path.join(__dirname + '/public/index.html'));
52 console.log(req.body.question + lastQuestion);
53 analyzeConversationAndWriteToLTM(lastQuestion, req.body.inputTwo);
54 lastQuestion = generateQuestion();
48 console.log(req.body.question + req.session.lastQuestion);
49 analyzeConversationAndWriteToLTM(req.session.lastQuestion, req.body.inputTwo);
50 req.session.lastQuestion = generateQuestion();
51 res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: false});
55 - res.render(__dirname + '/public/index.html', {response: "Hello!", question: lastQuestion, instructions: false});
5652 });
5753
5854 app.post("/regenerate", (req, res) => {
59 - lastQuestion = generateQuestion();
60 - res.render(__dirname + '/public/index.html', {response: "Hello!", question: lastQuestion, instructions: false});
55 req.session.lastQuestion = generateQuestion();
56 res.render(__dirname + '/public/index.html', {response: "Hello!", question: req.session.lastQuestion, instructions: false});
6157 });
And analyzeConversationAndWriteToLTM:
function analyzeConversationAndWriteToLTM(unrefinedFirstStatement, unrefinedSecondStatement){
updateLTMArrays();
var firstStatement = unrefinedFirstStatement.toLowerCase().replace(punctuation,"");
var secondStatement = unrefinedSecondStatement.toLowerCase().replace(punctuation,"");
if(prompts.includes(firstStatement) || secondStatement == "new question" || secondStatement == "newquestion" || secondStatement == "" || secondStatement == " " || firstStatement == "" || firstStatement == " "){
return;
} else {
if(!filter.isProfane(firstStatement) && !filter.isProfane(secondStatement)){
var finalFirstStatement = firstStatement;
var finalSecondStatement = capitalizeFirstLetter(unrefinedSecondStatement);
writeStatementToLTM(finalFirstStatement, finalSecondStatement);
updateLTMArrays();
console.clear();
} else {
console.log("Rude!");
}
}
}
/answer is the one that remembers the session.lastQuestion cookie. Anyways, even though I'm using cookies, session.lastQuestion is updated for every client when one client updates it, resulting in desyncing.
回答1:
You can't call both res.sendFile() and res.render() in the same request handler - pick one or the other. Both are trying to send a response to the incoming http request, but you only get to send one response per request. This is why you get the warning from Express "Can't set headers after they are sent." because when you go to send the second response, it sees that a response has already been sent and it encounters that when it tries to send the headers for the 2nd response.
If you think about it logically, the browser is making a request and will then display the response. Once it gets a response, the request is done. It is not expecting you to send yet another response and, in fact, Express won't allow you to send another response (thus why you get the warning you do).
来源：https://stackoverflow.com/questions/65544373/express-session-error-cant-send-headers-after-they-are-sent