Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript Express Basics Parameters, Query Strings, and Modularizing Routes Linking Around the Application

Karen Shea
Karen Shea
13,851 Points
Posted by Karen Shea
Karen Shea
13,851 Points

RangeError [ERR_HTTP_INVALID_STATUS_CODE]: Invalid status code: undefined Pretty sure the issue is in cards.js.

Pretty sure the issue is in cards.js.

Here is the entirety of that file:

```const express = require('express'); const router = express.Router(); const { data } = require('../data/flashcarddata.json'); const { cards } = data;

router.get('/', (req, res) => { const numberOfCards = cards.length; const flashcardId = Math.floor(Math.random() * numberOfCards); res.redirect(/cards/${flashcardId}); });

router.get('/:id', (req, res) => { const { side } = req.query; const { id } = req.params;

if (!side) { res.redirect(/cards/${id}?side=question) } const name = req.cookies.username; const text = cards[id][side]; const { hint } = cards[id];

const templateData = { id, text, name };

if (side === 'question') {
    templateData.hint = hint;
    templateData.sideToShow = 'answer';
    templateData.sideToShowDisplay = 'Answer';
} else if (side === 'answer') {
    templateData.sideToShow = 'question';
    templateData.sideToShowDisplay = 'Question';
}

res.render('card', templateData);

});

module.exports = router;```

2 Answers

Kevin Gates
Kevin Gates
14,855 Points
Kevin Gates
Kevin Gates
14,855 Points

Okay, I've had to deal with this. It's requiring an HTTP status code, so I've used 302. So if you change from this:

res.redirect(/cards/${flashcardId});

to this

res.status(302).redirect(`/cards/${flashcardId}`);

it should work.

Also though, for me the behavior is different. If I'm in the sub-folder already it sometimes results in cards/cards/3...

So to get this to work localhost:3000/cards/ and localhost:3000/cards/3 to work, I need to make my code this:

const express = require('express');
const router = express.Router();
const { data } = require('../data/flashcardData.json');
const { cards } = data;

router.get('/:id', (req, res) => {
    const { side } = req.query;
    const { id } = req.params;

    if ( !side ) {
        res.status(302).redirect(`${id}?side=question`)
    }

    const text = cards[id][side];
    const { hint } = cards[id];

    const templateData = { id, text };
    if (side === 'question') {
        templateData.hint = hint;
        templateData.sideToShow = "answer";
        templateData.sideToShowDisplay = "Answer";
    } else if (side === "answer") {
        templateData.sideToShow = "question";
        templateData.sideToShowDisplay = "Question";
    }
    res.render('card', templateData);
});

router.get('/', (req, res) => {
    const totalCards = cards.length;
    const randomCard = Math.floor(Math.random()*totalCards);
    res.status(302).redirect(`${randomCard}?side=question`);
});


module.exports = router;
Marie Franklin
Marie Franklin
12,505 Points
Marie Franklin
Marie Franklin
12,505 Points

One problem is that you are defining side as const and later reassigning it... instead you should define side with let

    let {side} = req.query;