从console.log获取值到html

Question

The function I have written works fine and the value correctly writes to my terminal onSubmit, however I'm struggling to piece together why this code isn't updating my html.

router.post('/index', function(req, res, next) {

  // ...Get form values, do calculations to get toCost value.

      console.log('$' + toCost);

      $(document).ready(function() {
        var output = document.getElementById('cost');
        output.innerHTML = toCost;
      });

  res.location('/');
  res.redirect('/');
})

I receive the following error and jquery is loading fine.

$ is not defined

Admittedly this is an over-engineered node/express app. The code snippet lives wrapped in a route file, inside a post request.

How do I get my value onto the html?

Jade layout

extends layout

block content
  form(...)
  div#cost

Answer 1

The normal way to do this would be as follows:

router.post('/index', function(req, res) {   <<< 'next' removed (only needed if using middleware)

  // ...Get form values, do calculations to get toCost value.

  console.log('$' + toCost);

  res.render('indexTemplate', {cost: toCost}); <<< pass toCost through to jade as 'cost'
});

Then in your jade file for the indexTemplate you can reference the 'cost' variable passed in like this:

indexTemplate.jade:

extends layout

block content
  form(...)
  div#cost #{cost} <<< adds the cost variable to page

Then the value of toCost will appear in the resulting page.

No jQuery is required on the server side.

Answer 2

jQuery is made for DOM manipulations and there's no DOM on a server. Try using 'jsdom'. jQuery is made for client side scripting, not for server-side client manipulations.

Answer 3

It seems that you're trying to make changes on client-side from your backend. It doesn't work that way.

You could create a variable on backend for storing calculation result. And get this value by get query from client-side

Answer 4

You're tring to reach DOM (that is on client side) from NodeJS on a server side. It doesn't work that way.