svn commit: r962231 - in /incubator/deltacloud/trunk/server/libexec: lib/deltacloud/base_driver.rb lib/deltacloud/base_driver/features.rb views/api/show.xml.haml

[lu...@apache.org]

Author: lutter
Date: Thu Jul  8 23:38:19 2010
New Revision: 962231

URL: http://svn.apache.org/viewvc?rev=962231&view=rev
Log:
Advertising of optional features

  * base_driver: add features and support for defining them in drivers
  * views (xml): list features for each collection in api.xml

Added:
    incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver/features.rb
Modified:
    incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver.rb
    incubator/deltacloud/trunk/server/libexec/views/api/show.xml.haml

Modified: incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver.rb
URL: http://svn.apache.org/viewvc/incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver.rb?rev=962231&r1=962230&r2=962231&view=diff
==============================================================================
--- incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver.rb (original)
+++ incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver.rb Thu Jul  8 23:38:19 2010
@@ -16,3 +16,4 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 
 require 'deltacloud/base_driver/base_driver'
+require 'deltacloud/base_driver/features'

Added: incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver/features.rb
URL: http://svn.apache.org/viewvc/incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver/features.rb?rev=962231&view=auto
==============================================================================
--- incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver/features.rb (added)
+++ incubator/deltacloud/trunk/server/libexec/lib/deltacloud/base_driver/features.rb Thu Jul  8 23:38:19 2010
@@ -0,0 +1,114 @@
+require 'deltacloud/validation'
+
+# Add advertising of optional features to the base driver
+module Deltacloud
+
+  class FeatureError < StandardError; end
+  class DuplicateFeatureDeclError < FeatureError; end
+  class DuplicateFeatureError < FeatureError; end
+  class UndeclaredFeatureError < FeatureError; end
+
+  class BaseDriver
+
+    # An operation on a collection like cretae or show. Features
+    # can add parameters to operations
+    class Operation
+      attr_reader :name
+
+      include Deltacloud::Validation
+
+      def initialize(name, &block)
+        @name = name
+        @params = {}
+        instance_eval &block
+      end
+    end
+
+    # The declaration of a feature, defines what operations
+    # are modified by it
+    class FeatureDecl
+      attr_reader :name, :operations
+
+      def initialize(name, &block)
+        @name = name
+        @operations = []
+        instance_eval &block
+      end
+
+      def description(text=nil)
+        @description = text if text
+        @description
+      end
+
+      def operation(name, &block)
+        @operations << Operation.new(name, &block)
+      end
+    end
+
+    # A specific feature enabled by a driver (see +feature+)
+    class Feature
+      attr_reader :decl
+
+      def initialize(decl, &block)
+        @decl = decl
+        instance_eval &block if block_given?
+      end
+
+      def name
+        decl.name
+      end
+
+      def operations
+        decl.operations
+      end
+
+      def description
+        decl.description
+      end
+    end
+
+    def self.feature_decls
+      @@feature_decls ||= {}
+    end
+
+    def self.feature_decl_for(collection, name)
+      decls = feature_decls[collection]
+      if decls
+        decls.find { |dcl| dcl.name == name }
+      else
+        nil
+      end
+    end
+
+    # Declare a new feature
+    def self.declare_feature(collection, name, &block)
+      feature_decls[collection] ||= []
+      raise DuplicateFeatureDeclError if feature_decl_for(collection, name)
+      feature_decls[collection] << FeatureDecl.new(name, &block)
+    end
+
+    def self.features
+      @@features ||= {}
+    end
+
+    # Declare in a driver that it supports a specific feature
+    def self.feature(collection, name, &block)
+      features[collection] ||= []
+      if features[collection].find { |f| f.name == name }
+        raise DuplicateFeatureError
+      end
+      unless decl = feature_decl_for(collection, name)
+        raise UndeclaredFeatureError, "No feature #{name} for #{collection}"
+      end
+      features[collection] << Feature.new(decl, &block)
+    end
+
+    def features(collection)
+      self.class.features[collection] || []
+    end
+
+    #
+    # Declaration of optional features
+    #
+  end
+end

Modified: incubator/deltacloud/trunk/server/libexec/views/api/show.xml.haml
URL: http://svn.apache.org/viewvc/incubator/deltacloud/trunk/server/libexec/views/api/show.xml.haml?rev=962231&r1=962230&r2=962231&view=diff
==============================================================================
--- incubator/deltacloud/trunk/server/libexec/views/api/show.xml.haml (original)
+++ incubator/deltacloud/trunk/server/libexec/views/api/show.xml.haml Thu Jul  8 23:38:19 2010
@@ -1,3 +1,5 @@
 %api{ :version=>@version, :driver=>DRIVER }
   - for entry_point in entry_points
     %link{ :rel=>entry_point[0], :href=>entry_point[1] }
+      - for feature in driver.features(entry_point[0])
+        %feature{ :name=>feature.name }