how to render conditional templates in res.render()

[moezbenrebah]

Hi everyone, I'm a student in web development, I built a web application, where I tried to implement in one of the route handler function a way to render 2 templates whenever its condition is fulfilled, but I didn't figure out how to reach my goal, so I tried like below, but it didn't work:

exports.myBookedTravels = catchAsyncHandler( async(req, res, next) => {
  // find all booked travels based on user id
  const bookedTravels = await Booking.find({ user: req.user.id });

  // find all travels that includes the above id (bookedTravels)
  const travelsIds = bookedTravels.map(item => item.travel);
  const travels = await Travel.find({ _id: { $in: travelsIds } });

  // Render the page that contains the booked travels || an empty page with a simple text
  if (!bookedTravels) res.render('nobooking')
  else {
    res.status(200).render('overview', {
      title: 'My travels',
      travels
    });
  }
});

Sorry, I'm a beginner and I try to find an adequate solution to my case but I didn't, and I'll appreciate your suggestions

[blakeembrey]

This is more learning how JavaScript works than anything about Express, but either your code is throwing an error or it's never going into the if statement. I don't know what .find returns, but assuming it's an array based on using .map below that means it'd be empty and you want to check !bookedTravels.length instead. An empty array is still truthy.

Example:

![] // false
![1,2,3] // false

[moezbenrebah]

Maybe I didn't explain clearly above, but the code is supposed to serve the user booking history so there is no error to reject, and yes the map returns an array of booked travel that includes the user id, so if the length of "travelsIds.length !== 0" it should show them up (and that's already done) otherwise it should show non-empty page but a simple text like "there are no booked travels yet" and that's the purpose of 'nobooking' template.
I reformulate my question here: how to serve multiple templates with res.render() in Express.js?
I already tried a code like the one below but the output was an error:

if (travelsIds.length === 0) {
  res.status(200).render('nobooking')
} else {
  res.status(200).render('overview', {
    title: 'My travels',
    travels
  });
}

[dougwilson]

Hi, sorry for your troubles. That is the correct way to server multiple templates.

It may help us help you if you could perhaps post what the error you are getting is? Or complete code that we can run.

[moezbenrebah]

Hi @dougwilson! thanks for your reply, now it works and I used the same code above, maybe yesterday I didn't have a good focus on it