latex-mk: use requirement

1 files changed, 17 insertions, 5 deletions

diff --git a/Library/Formula/latex-mk.rb b/Library/Formula/latex-mk.rb
index e6ffaf060..b91c7b62d 100644
--- a/Library/Formula/latex-mk.rb
+++ b/Library/Formula/latex-mk.rb
@@ -1,19 +1,31 @@
 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 'latex'
+  end
+  def fatal?
+    true
+  end
+end
+
 class LatexMk < Formula
   homepage 'http://latex-mk.sourceforge.net/index.html'
   url 'http://sourceforge.net/projects/latex-mk/files/latex-mk/latex-mk-2.1/latex-mk-2.1.tar.gz'
   sha1 '8460fd1f3c716e5759828c2a5af76eeafbce8d10'
 
-  env :userpaths
+  depends_on TexInstalled.new
+  env :userpaths # To find TeX
 
   def install
     system "./configure", "--disable-debug", "--disable-dependency-tracking",
                           "--prefix=#{prefix}"
     system "make install"
   end
-
-  def caveats
-    "latex-mk requires a version of TeX, such as TeX Live or MacTeX."
-  end
 end