Question 270622 in Javascript Question posted in
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Javascript – How do I pass a value from the app file to a router file with express

I am writing an express app with multiple routes. Each route will have it’s own file for modularity and all route files will be in a routes folder.

I have a value that is reused across all the routes. How do I share it from my app.js file to a route.js file.

Example

//app.js file

const express = require("express");

const app = express();

const port = 3000;

const url = "https://example.com/v1"; // how do I pass this value to the test route below?

const test = require("./routes/test")

app.use(express.json());



app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});

// routes/test.js

const express = require("express");
const router = express.Router();


//middleware for requests
router.use((req, res, next) => {
  console.log("Time:", Date.now());
  next();
});


router.post("/", (req, res) => {
 console.log(url)
});
Tags:

2

Answers


  1. 0

    You can make the routes as function and pass params like

    your main file

    const v1Routes = require('./routes/v1/');

app.use('/', middleware(), v1Routes({ userid : 123 }));

    you route file

    const routes = require('express').Router({ mergeParams: true })

module.exports = (params) => {
    routes.use('/user', require('./user')(params));
    return routes;
}

    your controller file

    module.exports = (params) => {
    return (req, res, next) => {

        console.log(params.userid)
        res.status(200).json({ message: 'All good' });

    }
}
    Login or Signup to reply.
  2. 0

    app.js I am missing app.use("/test", test) and you can change const test = require("./routes/test") to const test = require("./routes/test")(url):

    const express = require("express");
const app = express();

const port = 3000;
const url = "https://example.com/v1";

//const test = require("./routes/test")
const test = require("./routes/test")(url);

app.use(express.json());
app.use("/test", test);

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});

    routes/test.js: I am missing a module.exports

    const express = require("express");
const router = express.Router();

module.exports = (url) => {
  router.post("/", (req, res) => {
    res.json({ url: url });
  });
  
  return router;
};

    request: test it with

    curl --location --request POST 'http://localhost:3000/test'
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