Setting a conditional for username in URL?

Question

Similarly to how Craft knows that a category is defined when a category slug is used, is there a way to detect a user in the same way?

{% if category is defined %}
...
{% endif %}

Something along the lines of (which only returns true if a user is logged in):

{% if user is defined %}
...
{% endif %}

If a username is in the URL, would/should above code return true similarly to how {% if category is defined %} returns true if a category slug is in the URL? (i.e. .com/news/sherlock_holmes)

I'm able to return author posts using method listed in this question, I'm just trying to simplify even further and have one template list all these views.

Answer 1

If you're looking for the current (logged in) user, you should use the global variable currentUser.

{% if currentUser %}
    {# currentUser returns a User Model if there is one, so do with it whatever you like #}
{% endif %}

However, if you want to find a user through a URL segment, you might want to get into using routes. If you use advanced routing, you can get what (I think) you want by adding following to your craft/config/routes.php:

return array(
    '(?P<category>[^/\]+)/(?P<user>[^/\]+)/' => 'path/to/template',
)

In your template, you can then use the variables {{ category }} and {{ user }}. Don't hang me on the RegExp-pattern, this is not tested but should get you further.