Liquid Markup space following optional value

Question

Is there a standard approach in Liquid Markup to the situation where you want to output a space following a value, but only if that value is present?

For example, let's say I have four values: prefix, first, middle, last. Everyone has first and last, but only some folks have prefix and/or middle.

If I just do {{prefix}} {{first}} {{middle}} {{last}}, then if there is no prefix or there is no middle name, I'll end up with extra spaces.

Mr. John Mortimer Smith <-- looks fine  
 Mary  Jones <-- looks weird, extra space at beginning and in middle

Naturally, I can do

{% if prefix != "" %}{{prefix}} {% endif %}{{first}} {% if middle != "" %}{{middle}} {% endif %}{{last}}

And that should work but seems messy. Is there a better way?

Thanks!

I was asked for an example. If I go to http://dotliquidmarkup.org/try-online and enter

{% assign first = "Mary" %} {% assign last = "Smith" %}
{{ prefix }} {{first}} {{middle}} {{last}}

Then I get

 Mary  Smith

(with a space before Mary and two spaces after Mary, since prefix and middle are null)

but I want to get

Mary Smith

Answer 1

http://dotliquidmarkup.org/try-online is presenting liquid parsing results in a <pre> tag that preserve whitespaces. That will not be the case in a standard html page where multiple spaces are presented a single one except in pre and code tags.

If you really want to get rid of multiple spaces, you can use normalize_whitespace filter.

whitespaces.md

---
title: Whitespaces
names:
  -
   prefix: m
   first: first
   middle: middle
   last: last
  -
   prefix: m
   first:
   middle: middle
   last: last
  -
   prefix:
   first: first
   middle:
   last: last
---
{% for p in page.names %}
{% capture fullName %}
  {{ p.prefix }} {{ p.first }}
  {{ p.middle }} {{ p.last }}
{% endcapture %}
<pre>|{{ fullName }}|</pre>
<pre>|{{ fullName | normalize_whitespace }}|</pre>
{% endfor %}

No more double spaces or any unnecessary whitespace.