是否可以从 express.js 中的路由器中提取前缀？

Question

I was wondering if it is possible to extract prefix from Router in express.js.

Here is my index.js file:

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

const admin = require("./admin");
const home = require("./home");

router.use("/admin", admin);
router.use("/", home);

// Catch All Other Pages
router.get("*", (req, res) => {
  res.render("404", { title: "404 Not Found" });
});

module.exports = router;

Here is my admin routes file:

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

router.get("/", function(req, res) {
  res.render("admin", { title: "Admin Menu" });
});

router.get("/settings", function(req, res) {
  res.render("admin/settings", { title: "Admin Menu | Settings" });
});

router.get("/logout", function(req, res) {
  //handle logout logic
  res.redirect("/");
});

module.exports = router;

In the index.js file I have set prefix to be '/admin';

Can I know extract this prefix in the admin.js file? Like for example:

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

// Require prefix
const prefix = router.getPrexix()?

router.get("/", function(req, res) {
  res.render("admin", { title: "Admin Menu", prefix });
});

router.get("/settings", function(req, res) {
  res.render("admin/settings", { title: "Admin Menu | Settings", prefix });
});

router.get("/logout", function(req, res) {
  //handle logout logic
  res.redirect("/");
});

module.exports = router;

Would it be possible to do this? I could reuse '/admin' in the pug templates.

Answer 1

In Express, req.baseUrl is the URL that the router was mounted on which would be "/admin" in your case.

And, you have req.path which is what the route matched.

And, you have req.originalUrl is the original URL so you can always use this in combination with either of the above to see the whole picture.

Here's a little example to illustrate:

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

const router = express.Router();

router.get("/new", (req, res) => {
    console.log("baseUrl", req.baseUrl);                // "/admin"
    console.log("path", req.path)                       // "/new"
    console.log("originalUrl", req.originalUrl);        // "/admin/new"
    res.send("new");
});

app.use("/admin", router);

app.listen(80);