javascript - How do I preserve line breaks when getting text from a textarea?

Question

I am getting the value in a textarea when the user hits submit. I then take this value and place it elsewhere on the page. However, when I do this, it loses newline characters making the output pretty ugly.

Here is the textarea I am accessing:

<textarea id="post-text" class="form-control" rows="3" placeholder="What's up?" required></textarea>

Here is the JavaScript code accessing the post and transcribing it.

var post = document.createElement('p');
var postText = document.getElementById('post-text').value;
post.append(postText);
var card = document.createElement('div');
card.append(post);
var cardStack = document.getElementById('#card-stack');
cardStack.prepend(card);

When the input is something like:

Group Schedule:

Tuesday practice @ 5th floor (8 pm - 11 pm)

Thursday practice @ 5th floor (8 pm - 11 pm)

Sunday practice @ (9 pm - 12 am)

The output is:

Group Schedule: Tuesday practice @ 5th floor (8 pm - 11 pm) Thursday practice @ 5th floor (8 pm - 11 pm) Sunday practice @ (9 pm - 12 am)

So is there a way to preserve line breaks?

Answer 1

The easiest solution is to simply style the element you're inserting the text into with the following CSS property:

white-space: pre-wrap;

This property causes whitespace and newlines within the matching elements to be treated in the same way as inside a <textarea>. That is, consecutive whitespace is not collapsed, and lines are broken at explicit newlines (but are also wrapped automatically if they exceed the width of the element).

Given that several of the answers posted here so far have been vulnerable to HTML injection (e.g. because they assign unescaped user input to innerHTML) or otherwise buggy, let me give an example of how to do this safely and correctly, based on your original code:

document.getElementById('post-button').addEventListener('click', function () {
  var post = document.createElement('p');
  var postText = document.getElementById('post-text').value;
  post.append(postText);
  var card = document.createElement('div');
  card.append(post);
  var cardStack = document.getElementById('card-stack');
  cardStack.prepend(card);
});

#card-stack p {
  background: #ddd;
  white-space: pre-wrap;  /* <-- THIS PRESERVES THE LINE BREAKS */
}
textarea {
  width: 100%;
}

<textarea id="post-text" class="form-control" rows="8" placeholder="What's up?" required>Group Schedule:

Tuesday practice @ 5th floor (8pm - 11 pm)

Thursday practice @ 5th floor (8pm - 11 pm)

Sunday practice @ (9pm - 12 am)</textarea><br>
<input type="button" id="post-button" value="Post!">
<div id="card-stack"></div>