Rails 3: How to display properly text from “textarea”?

Question

In my Rails 3 application I use textarea to let users to write a new message in a forum.

However, when the message is displayed, all newlines look like spac

Answer 1

CSS-only option

I believe one of the easiest options is to use css white-space: pre-line;

Other answers also mentioned using white-space, but I think it needs a little more information:

In most cases you should probably choose pre-line over pre-wrap. View the difference here.

It's very important to keep in mind about white-space that you should not do something like this:

<p style="white-space: pre-line;">
  <%= your.text %>
</p>

It will produce extra spaces and line-breaks in the output. Instead, go with this:

<p style="white-space: pre-line;"><%= your.text %></p>

HTML alternative

Another way is to wrap your text in <pre> tags. And last note on my CSS option is true here as well:

<p>
  <pre><%= your.text %></pre>
</p>

Don't separate your text from <pre> tags with spaces or line-breaks.

Final thoughts

After googling this matter a little I have a feeling that html-approach is considered less clean than the css one and we should go css-way. However, html-way seems to be more browser-compatible (supports archaic browsers, but who cares):

pre tag

white-space

Answer 2

Since simple_format does not do what you want, I'd make a simple helper method to convert newlines to <br>s:

def nl2br(s)
  s.gsub(/\n/, '<br>')
end

Then in your view you can use it like this:

<%= nl2br(h(@forum_post.message)) %>

Answer 3

If someone still gets redirected here and uses Rails 4: http://apidock.com/rails/v4.0.2/ActionView/Helpers/TextHelper/simple_format

You can now specify the tag it gets wrapped in (defaults to p) like so:

simple_format(my_text, {}, wrapper_tag: "div")
# => "<div>Here is some basic text...\n<br />...with a line break.</div>"