polipo: launchd plist

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/polipo.rb

@@ -12,5 +12,44 @@ class Polipo < Formula
     make_opts = "PREFIX=#{prefix} LOCAL_ROOT=#{share}/polipo/www DISK_CACHE_ROOT=#{cache_root} MANDIR=#{man} INFODIR=#{info} PLATFORM_DEFINES=-DHAVE_IPv6"
     system "make all #{make_opts}"
     system "make install #{make_opts}"
+
+    plist_path.write startup_plist
+    plist_path.chmod 0644
+  end
+
+  def startup_plist
+    return <<-EOPLIST
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+  <dict>
+    <key>Label</key>
+    <string>#{plist_name}</string>
+    <key>RunAtLoad</key>
+    <true/>
+    <key>KeepAlive</key>
+    <true/>
+    <key>UserName</key>
+    <string>#{`whoami`.chomp}</string>
+    <key>ProgramArguments</key>
+    <array>
+      <string>#{bin}/polipo</string>
+    </array>
+  </dict>
+</plist>
+    EOPLIST
+  end
+
+  def caveats; <<-EOS.undent
+    If this is your first install, automatically load on login with:
+        mkdir -p ~/Library/LaunchAgents
+        cp #{plist_path} ~/Library/LaunchAgents/
+        launchctl load -w ~/Library/LaunchAgents/#{plist_path.basename}
+
+    If this is an upgrade and you already have the #{plist_path.basename} loaded:
+        launchctl unload -w ~/Library/LaunchAgents/#{plist_path.basename}
+        cp #{plist_path} ~/Library/LaunchAgents/
+        launchctl load -w ~/Library/LaunchAgents/#{plist_path.basename}
+    EOS
   end
 end