节点js Express错误：ERR_TOO_MANY_REDIRECTS

Question

Everything worked just fine until all of a sudden this error occurred: ERR_TOO_MANY_REDIRECTS. I had no luck in figuring it out on my own so please help me if you can.

I use express-handlebars and express to route my pages and I thing I saw where the problem occurres. In my bookController file when I use res. render ('something') no matter from what route it always redirects me to '/' and when I use res. send ('something') It redirects to where it defined.

This is my app.js file:

 const express = require("express"); const mongoose = require("mongoose"); const passport = require("passport"); const path = require("path"); const bodyParser = require("body-parser"); const hbs = require("express-handlebars"); const cookieParser = require("cookie-parser"); const session = require("express-session"); const MongoStore = require("connect-mongo")(session); const flash = require("connect-flash"); const routes = require("./routes/index"); const expressValidator = require("express-validator"); const errorHandlers = require("./handlers/errorHandlers"); const app = express(); const webpack = require("webpack"); const webpackConfig = require("./webpack.config.js"); const compiler = webpack(webpackConfig); const webpackDevMiddleware = require("webpack-dev-middleware")( compiler, webpackConfig.devServer ); app.use(webpackDevMiddleware); app.use(require("webpack-hot-middleware")(compiler)); app.use(express.static(path.join(__dirname, "public"))); app.engine( "hbs", hbs({ extname: "hbs", defaultLayout: "main", layoutsDir: __dirname + "/views/layouts", partialsDir: __dirname + "/views/partials" }) ); app.set("views", path.join(__dirname, "views")); app.set("view engine", "hbs"); app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended: false })); app.use(flash()); app.use( session({ resave: false, saveUninitialized: false, secret: process.env.SECRET }) ); app.use(cookieParser()); app.use(expressValidator()); app.use((req, res, next) => { res.locals.flashes = req.flash(); next(); }); app.use("/", routes); app.use(errorHandlers.flashValidationErrors); module.exports = app; 

This is my index.js file

 const router = require("express").Router(); const bookController = require("../controllers/bookController"); const { catchErrors } = require("../handlers/errorHandlers"); router.get("/", bookController.home); router.post("/contact", catchErrors(bookController.contactForm)); router.post("/productPage", catchErrors(bookController.productForm)); module.exports = router; 

This is my bookController file:

 const mail = require("../handlers/mail"); exports.home = async (req, res) => { res.render("index"); }; exports.contactForm = async (req, res) => { const email = req.body.email; const subject = req.body.subject; const text = req.body.text; await mail.send({ email, subject, text }); res.redirect("/"); }; exports.productForm = async (req, res) => { console.log(req.body); res.redirect("/"); }; 

I will very appreciate any help. Thank you.

Answer 1

Answer which solved the question.

If res.render() does not stop the request (Same way as res.send(html) ), usually means there is error in the render function. As the behaviour of res.render() is that if it errors, it will trigger next(err) .

https://expressjs.com/en/api.html#res.render

When an error occurs, the method invokes next(err) internally.

Errors are quite simple to be tracked in the function, by passing an callback into the render;

res.render('index', function(err, html) {
  if (err) console.error(err);
  res.send(html);
});

Once you can trace the error and fix it, problem should be solved.