Added config.gem for specifying which gems are required by the application, as well as rake tasks for installing and freezing gems. [rick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9140 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 78 insertions, 0 deletions

diff --git a/railties/lib/rails/gem_dependency.rb b/railties/lib/rails/gem_dependency.rb
new file mode 100644
index 0000000000..ed16464887
--- /dev/null
+++ b/railties/lib/rails/gem_dependency.rb
@@ -0,0 +1,78 @@
+module Rails
+  class GemDependency
+    attr_accessor :name, :requirement, :version, :lib, :source
+
+    def self.unpacked_path
+      @unpacked_path ||= File.join(RAILS_ROOT, 'vendor', 'gems')
+    end
+
+    def initialize(name, options = {})
+      @name     = name.to_s
+      if options[:version]
+        @requirement = Gem::Requirement.create(options[:version])
+        @version     = @requirement.requirements.first.last
+      end
+      @lib      = options[:lib]
+      @source   = options[:source]
+      @loaded   = false
+      @load_paths_added = false
+      @unpack_directory = nil
+    end
+
+    def add_load_paths
+      return if @loaded || @load_paths_added
+      unpacked_paths = Dir[File.join(self.class.unpacked_path, "#{@name}-#{@version || "*"}")]
+      if unpacked_paths.empty?
+        args = [@name]
+        args << @requirement.to_s if @requirement
+        gem *args
+      else
+        $LOAD_PATH << File.join(unpacked_paths.first, 'lib')
+      end
+      @load_paths_added = true
+    rescue Gem::LoadError
+      puts $!.to_s
+    end
+
+    def load
+      return if @load_paths_added == false
+      require(@lib || @name)
+      @loaded = true
+    rescue LoadError
+      puts $!.to_s
+      $!.backtrace.each { |b| puts b }
+    end
+
+    def loaded?
+      @loaded
+    end
+
+    def load_paths_added?
+      @load_paths_added
+    end
+
+    def install
+      Gem::GemRunner.new.run(install_command)
+    end
+
+    def unpack_to(directory)
+      FileUtils.mkdir_p directory
+      Dir.chdir directory do
+        Gem::GemRunner.new.run(unpack_command)
+      end
+    end
+
+    def install_command
+      cmd = %w(install) << @name
+      cmd << "--version" << "#{@requirement.to_s}" if @requirement
+      cmd << "--source"  << @source  if @source
+      cmd
+    end
+    
+    def unpack_command
+      cmd = %w(unpack) << @name
+      cmd << "--version" << "#{@requirement.to_s}" if @requirement
+      cmd
+    end
+  end
+end
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