11 files changed, 221 insertions, 120 deletions

diff --git a/Library/Formula/asymptote.rb b/Library/Formula/asymptote.rb
index 19b536be7..a873b416c 100644
--- a/Library/Formula/asymptote.rb
+++ b/Library/Formula/asymptote.rb
@@ -1,24 +1,32 @@
 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 Asymptote < Formula
   homepage 'http://asymptote.sourceforge.net/'
   url 'http://downloads.sourceforge.net/asymptote/asymptote-2.15.src.tgz'
   md5 '1adb969a4d7b17a3ae98728d1956bd77'
 
+  depends_on TexInstalled.new
+
   depends_on 'readline'
   depends_on 'bdw-gc'
 
   def install
-    unless which 'latex'
-      onoe <<-EOS.undent
-        Asymptote requires a TeX/LaTeX installation; aborting now.
-        You can obtain the TeX distribution for Mac OS X from
-            http://www.tug.org/mactex/
-      EOS
-      exit 1
-    end
-
-    texmfhome = share + 'texmf'
+    texmfhome = share+'texmf'
 
     # see: https://sourceforge.net/tracker/?func=detail&aid=3486838&group_id=120000&atid=685683
     inreplace 'configure', '--no-var-tracking', '' if ENV.compiler == :clang
diff --git a/Library/Formula/auctex.rb b/Library/Formula/auctex.rb
index d36b3df3c..2a199c264 100644
--- a/Library/Formula/auctex.rb
+++ b/Library/Formula/auctex.rb
@@ -1,11 +1,28 @@
 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 Auctex < Formula
   homepage 'http://ftp.gnu.org/pub/gnu/auctex'
   url 'http://ftpmirror.gnu.org/auctex/auctex-11.86.tar.gz'
   mirror 'http://ftp.gnu.org/gnu/auctex/auctex-11.86.tar.gz'
   md5 '6bc33a67b6ac59db1aa238f3693b36d2'
 
+  depends_on TexInstalled.new
+
   def options
     [['--with-emacs=</full/path/to/emacs>', "Force a different emacs"]]
   end
@@ -21,15 +38,6 @@ class Auctex < Formula
   end
 
   def install
-    unless which 'latex'
-      onoe <<-EOS.undent
-        AUCTeX requires a TeX/LaTeX installation; aborting now.
-        You can obtain the TeX distribution for Mac OS X from
-            http://www.tug.org/mactex/
-      EOS
-      exit 1
-    end
-
     # configure fails if the texmf dir is not there yet
     brew_texmf = share + 'texmf'
     brew_texmf.mkpath
diff --git a/Library/Formula/dbslayer.rb b/Library/Formula/dbslayer.rb
index 2b2e32cb4..dec1e3e93 100644
--- a/Library/Formula/dbslayer.rb
+++ b/Library/Formula/dbslayer.rb
@@ -1,34 +1,39 @@
 require 'formula'
 
+class MySqlInstalled < Requirement
+  def message; <<-EOS.undent
+    MySQL is required to install.
+
+    You can install this with Homebrew using:
+      brew install mysql-connector-c
+        For MySQL client libraries only.
+
+      brew install mysql
+        For MySQL server.
+
+    Or you can use an official installer from:
+      http://dev.mysql.com/downloads/mysql/
+    EOS
+  end
+  def satisfied?
+    which 'mysql_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Dbslayer < Formula
   homepage 'http://code.nytimes.com/projects/dbslayer/wiki'
   url 'http://code.nytimes.com/downloads/dbslayer-beta-12.tgz'
   version '0.12.b'
   md5 'a529ea503c244d723166f78c75df3bb3'
 
-  def install
-    unless which 'mysql_config'
-      opoo "No MySQL client library detected"
-      puts "This formula may fail to build, see caveats for more information."
-    end
+  depends_on MySqlInstalled.new
 
+  def install
     system "./configure", "--prefix=#{prefix}"
     system "make"
     system "make install"
   end
-
-  def caveats; <<-EOS.undent
-    DBSlayer depends on a MySQL client library.
-
-    You can install this with Homebrew using:
-      brew install mysql
-        For MySQL server.
-
-      brew install mysql-connector-c
-        For MySQL client libraries only.
-
-    We don't install these for you when you install this formula, as
-    we don't know which datasource you intend to use.
-    EOS
-  end
 end
diff --git a/Library/Formula/git-hg.rb b/Library/Formula/git-hg.rb
index 153062fee..fac0be430 100644
--- a/Library/Formula/git-hg.rb
+++ b/Library/Formula/git-hg.rb
@@ -1,16 +1,28 @@
 require 'formula'
 
+class HgInstalled < Requirement
+  def message; <<-EOS.undent
+    Mercurial is required to use this software.
+
+    You can install this with Homebrew using:
+      brew install mercurial
+
+    Or you can use an official installer from:
+      http://mercurial.selenic.com/
+    EOS
+  end
+  def satisfied?
+    which 'hg'
+  end
+end
+
 class GitHg < Formula
   head 'https://github.com/offbytwo/git-hg.git'
   homepage 'http://offbytwo.com/git-hg/'
 
-  def install
-    unless which 'hg'
-      puts "You may need to install Mercurial before using this software:"
-      puts "  brew install mercurial"
-    end
+  depends_on HgInstalled.new
 
+  def install
     prefix.install Dir['*']
   end
 end
-
diff --git a/Library/Formula/jstalk.rb b/Library/Formula/jstalk.rb
index d13cd3919..65af1eeea 100644
--- a/Library/Formula/jstalk.rb
+++ b/Library/Formula/jstalk.rb
@@ -1,21 +1,25 @@
 require 'formula'
 
+class NeedsSnowLeopard < Requirement
+  def satisfied?
+    MacOS.snow_leopard?
+  end
+
+  def message
+    "jstalk requires Mac OS X 10.6 or newer"
+  end
+end
+
 class Jstalk < Formula
-  url 'https://github.com/ccgus/jstalk.git', :tag => "v1.0.1"
   homepage 'http://jstalk.org/'
+  url 'https://github.com/ccgus/jstalk.git', :tag => "v1.0.1"
   version '1.0.1'
 
-  def install
-    if MacOS.leopard?
-      onoe "jstalk requires Mac OS X 10.6+"
-      exit 1
-    end
+  depends_on NeedsSnowLeopard.new
 
-    args = ["-configuration", "Release", "ONLY_ACTIVE_ARCH=YES"]
-    targets = ["JSTalk Framework", "jstalk command line", "JSTalk Editor"]
-
-    targets.each do |target|
-      system "xcodebuild", "-target", target, *args
+  def install
+    ["JSTalk Framework", "jstalk command line", "JSTalk Editor"].each do |t|
+      system "xcodebuild", "-target", t, "-configuration", "Release", "ONLY_ACTIVE_ARCH=YES"
     end
 
     cd 'build/Release' do
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
diff --git a/Library/Formula/mydumper.rb b/Library/Formula/mydumper.rb
index 5e897c051..0e3d9f7af 100644
--- a/Library/Formula/mydumper.rb
+++ b/Library/Formula/mydumper.rb
@@ -1,25 +1,40 @@
 require 'formula'
 
+class MySqlInstalled < Requirement
+  def message; <<-EOS.undent
+    MySQL is required to install.
+
+    You can install this with Homebrew using:
+      brew install mysql-connector-c
+        For MySQL client libraries only.
+
+      brew install mysql
+        For MySQL server.
+
+    Or you can use an official installer from:
+      http://dev.mysql.com/downloads/mysql/
+    EOS
+  end
+  def satisfied?
+    which 'mysql_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Mydumper < Formula
   homepage 'http://www.mydumper.org/'
   url 'http://launchpadlibrarian.net/77098505/mydumper-0.5.1.tar.gz'
   md5 'b4df42dfe23f308ab13eb6ecb73a0d21'
 
+  depends_on MySqlInstalled.new
   depends_on 'pkg-config' => :build
   depends_on 'cmake' => :build
   depends_on 'glib'
   depends_on 'pcre'
 
   def install
-    unless which 'mysql_config'
-      opoo "`mysql_config` was not found"
-      puts "This software requires the MySQL client libraries."
-      puts "You can install them via Homebrew with one of these:"
-      puts "  brew install mysql-connector-c"
-      puts "  brew install mysql [--client-only]"
-      puts "Without the client libraries, this formula will fail to compile."
-    end
-
     system "cmake #{std_cmake_parameters} ."
     system "make install"
   end
diff --git a/Library/Formula/mysql-proxy.rb b/Library/Formula/mysql-proxy.rb
index eadffe616..29b6720a4 100644
--- a/Library/Formula/mysql-proxy.rb
+++ b/Library/Formula/mysql-proxy.rb
@@ -1,25 +1,40 @@
 require 'formula'
 
+class MySqlInstalled < Requirement
+  def message; <<-EOS.undent
+    MySQL is required to install.
+
+    You can install this with Homebrew using:
+      brew install mysql-connector-c
+        For MySQL client libraries only.
+
+      brew install mysql
+        For MySQL server.
+
+    Or you can use an official installer from:
+      http://dev.mysql.com/downloads/mysql/
+    EOS
+  end
+  def satisfied?
+    which 'mysql_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class MysqlProxy < Formula
   url 'http://launchpad.net/mysql-proxy/0.8/0.8.0/+download/mysql-proxy-0.8.0.tar.gz'
   homepage 'https://launchpad.net/mysql-proxy'
   md5 'b6a9748d72e8db7fe3789fbdd60ff451'
 
+  depends_on MySqlInstalled.new
   depends_on 'pkg-config' => :build
   depends_on 'glib'
   depends_on 'libevent'
   depends_on 'lua'
 
   def install
-    unless which 'mysql_config'
-      opoo "`mysql_config` was not found"
-      puts "This software requires the MySQL client libraries."
-      puts "You can install them via Homebrew with one of these:"
-      puts "  brew install mysql-connector-c"
-      puts "  brew install mysql [--client-only]"
-      puts "Without the client libraries, this formula will fail to compile."
-    end
-
     system "./configure", "--disable-dependency-tracking",
                           "--prefix=#{prefix}",
                           # Ugh, don't dump these directly into /usr/local/include.
diff --git a/Library/Formula/pg_top.rb b/Library/Formula/pg_top.rb
index 4d88b1ed4..f5cdbd5aa 100644
--- a/Library/Formula/pg_top.rb
+++ b/Library/Formula/pg_top.rb
@@ -1,23 +1,33 @@
 require 'formula'
 
+class PostgresqlInstalled < Requirement
+  def message; <<-EOS.undent
+    PostgresQL is required to install.
+
+    You can install this with:
+      brew install postgresql
+
+    Or you can use an official installer from:
+      http://www.postgresql.org/
+    EOS
+  end
+  def satisfied?
+    which 'pg_config'
+  end
+  def fatal?
+    true
+  end
+end
+
+
 class PgTop < Formula
   homepage 'http://ptop.projects.postgresql.org/'
   url 'http://pgfoundry.org/frs/download.php/1781/pg_top-3.6.2.tar.gz'
   md5 '12ddb50cf83e3027d182a1381d388f1d'
 
-  def install
-    unless which 'pg_config'
-      opoo "No pg_config was detected."
-      puts <<-EOS.undent
-        pg_top requires postgresql in order to compile, but pg_config was not
-        found. This install will likely fail.
-
-        You can install this with:
-          brew install postgresql
-        or by using a package installer from the PostgreSQL project itself.
-      EOS
-    end
+  depends_on PostgresqlInstalled.new
 
+  def install
     system "./configure", "--disable-debug", "--disable-dependency-tracking",
                           "--prefix=#{prefix}"
     system "make install"
diff --git a/Library/Formula/pgtap.rb b/Library/Formula/pgtap.rb
index 16415304a..fc5149253 100644
--- a/Library/Formula/pgtap.rb
+++ b/Library/Formula/pgtap.rb
@@ -1,25 +1,32 @@
 require 'formula'
 
+class PostgresqlInstalled < Requirement
+  def message; <<-EOS.undent
+    PostgresQL is required to install.
+
+    You can install this with:
+      brew install postgresql
+
+    Or you can use an official installer from:
+      http://www.postgresql.org/
+    EOS
+  end
+  def satisfied?
+    which 'pg_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Pgtap < Formula
   url 'http://pgfoundry.org/frs/download.php/2701/pgtap-0.24.tar.bz2'
   homepage 'http://pgtap.org'
   md5 '9d0360c87fca0ddf3ca9da49b9b71947'
 
-  skip_clean :all
+  depends_on PostgresqlInstalled.new
 
   def install
-    unless which 'pg_config'
-      opoo "No pg_config was detected."
-      puts <<-EOS.undent
-        pg_top requires postgresql in order to compile, but pg_config was not
-        found. This install will likely fail.
-
-        You can install this with:
-          brew install postgresql
-        or by using a package installer from the PostgreSQL project itself.
-      EOS
-    end
-
     system "make install"
     bin.install %w(bbin/pg_prove bbin/pg_tapgen)
   end
diff --git a/Library/Formula/skytools.rb b/Library/Formula/skytools.rb
index 34572dec5..e8ab6f41f 100644
--- a/Library/Formula/skytools.rb
+++ b/Library/Formula/skytools.rb
@@ -1,23 +1,32 @@
 require 'formula'
 
+class PostgresqlInstalled < Requirement
+  def message; <<-EOS.undent
+    PostgresQL is required to install.
+
+    You can install this with:
+      brew install postgresql
+
+    Or you can use an official installer from:
+      http://www.postgresql.org/
+    EOS
+  end
+  def satisfied?
+    which 'pg_config'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Skytools < Formula
   homepage 'http://pgfoundry.org/projects/skytools/'
   url 'http://pgfoundry.org/frs/download.php/2872/skytools-2.1.12.tar.gz'
   md5 '94f3391d5b3c3ac6c2edcbfbda705573'
 
-  def install
-    unless which 'pg_config'
-      opoo "No pg_config was detected."
-      puts <<-EOS.undent
-        pg_top requires postgresql in order to compile, but pg_config was not
-        found. This install will likely fail.
-
-        You can install this with:
-          brew install postgresql
-        or by using a package installer from the PostgreSQL project itself.
-      EOS
-    end
+  depends_on PostgresqlInstalled.new
 
+  def install
     system "./configure", "--prefix=#{prefix}"
     system "make"
     system "make install"