Use new Requirements in formulae

1 files changed, 17 insertions, 9 deletions

diff --git a/Library/Formula/lilypond.rb b/Library/Formula/lilypond.rb
index bbc78b119..22f466c81 100644
--- a/Library/Formula/lilypond.rb
+++ b/Library/Formula/lilypond.rb
@@ -1,10 +1,26 @@
 require 'formula'
 
+class TexInstalled < Requirement
+  def message; <<-EOS.undent
+    A TeX/LaTeX installation is required to install.
+    You can obtain the TeX distribution for Mac OS X from:
+        http://www.tug.org/mactex/
+    EOS
+  end
+  def satisfied?
+    which 'mpost'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Lilypond < Formula
-  url 'http://download.linuxaudio.org/lilypond/sources/v2.14/lilypond-2.14.2.tar.gz'
   homepage 'http://lilypond.org/'
+  url 'http://download.linuxaudio.org/lilypond/sources/v2.14/lilypond-2.14.2.tar.gz'
   md5 '4053a19e03181021893981280feb9aaa'
 
+  depends_on TexInstalled.new
   depends_on 'pkg-config' => :build
   depends_on 'gettext'
   depends_on 'pango'
@@ -17,8 +33,6 @@ class Lilypond < Formula
   skip_clean :all
 
   def install
-    abort caveats unless which "mpost"
-
     gs = Formula.factory('ghostscript')
     system "./configure", "--prefix=#{prefix}",
                           "--with-ncsb-dir=#{gs.share}/ghostscript/fonts/"
@@ -27,10 +41,4 @@ class Lilypond < Formula
     system "make"
     system "make install"
   end
-
-  def caveats; <<-EOS.undent
-    Lilypond requires a version of TeX, such as TeX Live or MacTeX, prior to installing.
-    Available at: http://www.tug.org/mactex/
-    EOS
-  end
 end