From 7406a627f8fcfbebea49521f9dbd2e12d54c3a29 Mon Sep 17 00:00:00 2001
From: Chris Eppstein <chris@eppsteins.net>
Date: Sat, 13 Nov 2010 00:46:41 -0800
Subject: [PATCH] A new function: if()

---
 doc-src/content/CHANGELOG.markdown          | 2 ++
 lib/compass/sass_extensions/functions.rb    | 3 ++-
 lib/compass/sass_extensions/functions/if.rb | 9 +++++++++
 test/sass_extensions_test.rb                | 5 +++++
 4 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 lib/compass/sass_extensions/functions/if.rb

diff --git a/doc-src/content/CHANGELOG.markdown b/doc-src/content/CHANGELOG.markdown
index c39cea10..a4aa151f 100644
--- a/doc-src/content/CHANGELOG.markdown
+++ b/doc-src/content/CHANGELOG.markdown
@@ -47,6 +47,8 @@ COMPASS CHANGELOG
   If you provide a number with units of `deg` then it will return a unitless number
   after converting to radians. Otherwise, it assumes the number is a radian length measure
   and passes the units along to the result.
+* A new function `if()` that allows you to switch on a value without using `@if`.
+  Usage: `if($truth-value, $value-if-true, $value-if-false)`.
 
 ### Rails
 
diff --git a/lib/compass/sass_extensions/functions.rb b/lib/compass/sass_extensions/functions.rb
index 922268e4..b8e566e6 100644
--- a/lib/compass/sass_extensions/functions.rb
+++ b/lib/compass/sass_extensions/functions.rb
@@ -2,7 +2,7 @@ module Compass::SassExtensions::Functions
 end
 
 %w(
-  selectors enumerate urls display
+  selectors enumerate urls display if
   inline_image image_size gradient_support
   font_files constants lists colors trig
 ).each do |func|
@@ -22,6 +22,7 @@ module Sass::Script::Functions
   include Compass::SassExtensions::Functions::Lists
   include Compass::SassExtensions::Functions::Colors
   include Compass::SassExtensions::Functions::Trig
+  include Compass::SassExtensions::Functions::If
 end
 
 # Wierd that this has to be re-included to pick up sub-modules. Ruby bug?
diff --git a/lib/compass/sass_extensions/functions/if.rb b/lib/compass/sass_extensions/functions/if.rb
new file mode 100644
index 00000000..98c1591d
--- /dev/null
+++ b/lib/compass/sass_extensions/functions/if.rb
@@ -0,0 +1,9 @@
+module Compass::SassExtensions::Functions::If
+  def if(truth, if_true, if_false)
+    if truth.to_bool
+      if_true
+    else
+      if_false
+    end
+  end
+end
diff --git a/test/sass_extensions_test.rb b/test/sass_extensions_test.rb
index 601ff0c4..bee9a8be 100644
--- a/test/sass_extensions_test.rb
+++ b/test/sass_extensions_test.rb
@@ -59,6 +59,11 @@ class SassExtensionsTest < Test::Unit::TestCase
     assert_equal "25%", evaluate("saturation(adjust-saturation(hsl(50deg, 50%, 50%), -25%))")
   end
 
+  def test_if_function
+    assert_equal "no", evaluate("if(false, yes, no)")
+    assert_equal "yes", evaluate("if(true, yes, no)")
+  end
+
   def test_trig_functions
     assert_equal "0.841px", evaluate("sin(1px)")
     assert_equal "0.0", evaluate("sin(pi())")