---
title:  Features
blurb:  Features work similarly to targets, but give you much more fine-grained
        control.
layout: template-logo-medium
---
<%= md_links %>
<%= md_images %>


<%= current_page.data.title %>
==============================

<%= current_page.data.blurb %>


Demonstrations
---------------

* * *

<% if target_feature?(:feature_advertise_pro) %>
**New! Today Only!!! Act before this special offer is gone forever!** Why settle
for the limitations of _Middlemac Free_ when you can upgrade to _Middlemac Pro_
for this limited time, special price of only $1299.99?

(Note: there is no _Middlemac Pro_. This is part of the Features demonstration.)

* * *
<% end %>


<% if target_feature?(:feature_performs_miracles) %>
If you open your water faucet, clean, safe, potable water will flow out of it.
_Middlemac_ has made this miracle happen for you.

* * *
<% end %>


<% if target_feature?(:feature_insults_user) %>
If you have made it this far, dear reader, you should know that if brains were
dynamite, you wouldn’t have enough to blow your nose.
<% else %>
If you have made it this far, dear reader, you should know that you are one of
the best people in the world.
<% end %>

* * *

<% if target_feature?(:feature_shows_pink_rectangle) %>
I made a special, pink rectangle just for you!
<svg style="width:50px; height:35px; display:block; margin:auto;">
  <rect width="50" height="35" style="fill:pink;stroke-width:0" />
</svg>
<% else %>
Too bad; other people got to see a nice, pink rectangle.
<% end %>

* * *


Recall our targets’ `feature` settings
--------------------------------------

Our `:free` target uses these `feature` settings:

~~~ ruby
:feature_advertise_pro        => true,
:feature_performs_miracles    => false,
:feature_insults_user         => true,
:feature_shows_pink_rectangle => true,
~~~

And `:pro` was setup with these `feature` settings:

~~~ ruby
:feature_advertise_pro        => false,
:feature_performs_miracles    => true,
:feature_insults_user         => false,
:feature_shows_pink_rectangle => true,
~~~

Depending on the target that you are currently viewing, you should very easily
be able to correlate what appears in the **Demonstrations** section with the
`feature`s settings above. Try changing some of the values and see what happens
to this page.


Targets vs Features
-------------------

While you can use targets exclusively, it’s then up to you to decide which
content you want to include in each of your help books when your Mac OS X
applications have different features. For example, what happens when you decide
to enable or disable a feature in a future release of your application? If you
use targets alone, you’ll have to go back and make a lot of changes to your
help content. If you use **features**, instead, it’s as simple as toggling the
value of your target’s `:features` sub-key between `true` and `false`.


How did this work?
------------------
Features work nearly identically to [targets][targets]. Instead of using the
`target_name?` helper, use the `target_feature?` helper instead. For example:

~~~ erb
<%% if target_feature?(:feature_insults_user) %>
If you have made it this far, dear reader, you should know that if brains were
dynamite, you wouldn’t have enough to blow your nose.
<%% else %>
If you have made it this far, dear reader, you should know that you are one of
the best people in the world.
<%% end %>
~~~


Include or exclude entire pages
-------------------------------

Just as with targets, you can use front matter `target` and `exclude` to include
or exclude entire pages.