Implemented merging defaults settings with namespaced settings using …

…default_namespace

README.rdoc

@@ -139,6 +139,59 @@ Finally, you can reload all your settings later as well:
 
 This is useful if you want to support changing your settings YAML without restarting your app.
 
+=== 5. Default namespace using
+
+Sometimes you want to have some defaults/common section in your settings file and inherit it for each namespace:
+
+  # app/config/application.yml
+  defaults:
+    cool:
+      saweet: nested settings
+    neat_setting: 24
+    awesome_setting: <%= "Did you know 5 + 5 = #{5 + 5}?" %>
+
+  development:
+    neat_setting: 800
+
+  production:
+
+Just declare default_namespace in your model:
+
+  class Settings < Settingslogic
+    source "#{Rails.root}/config/application.yml"
+    namespace Rails.env
+    default_namespace "defaults"
+  end
+
+Access it
+
+  >> Rails.env
+  => "development"
+  >> Settings.cool.saweet
+  => "nested settings"
+  >> Settings.neat_setting
+  => 800
+
+  >> Rails.env
+  => "production"
+  >> Settings.cool.saweet
+  => "nested settings"
+  >> Settings.neat_setting
+  => 24
+
+  >> Rails.env
+  => "test"
+  >> Settings.cool.saweet
+  => "nested settings"
+  >> Settings.neat_setting
+  => 24
+
+Notes:
+
+* If specified namespace does not exist you will have default settings. So you don't need to write extra borring line if you have a lot of namespaces that just use default settings.
+* If specified default namespace does not exists you will have just settings for your namespace
+* If both (default_namespace and namespace) do not exist you will have all settings from file.
+
 == Author
 
 Copyright (c) 2008-2010 {Ben Johnson}[http://github.com/binarylogic] of {Binary Logic}[http://www.binarylogic.com],

lib/settingslogic.rb

@@ -28,6 +28,14 @@ def source(value = nil)
       end
     end
 
+    def default_namespace(value = nil)
+      if value.nil?
+        @default_namespace
+      else
+        @default_namespace = value
+      end
+    end
+
     def namespace(value = nil)
       if value.nil?
         @namespace
@@ -103,8 +111,8 @@ def initialize(hash_or_file = self.class.source, section = nil)
       self.replace hash_or_file
     else
       hash = YAML.load(ERB.new(File.read(hash_or_file)).result).to_hash
-      hash = hash[self.class.namespace] if self.class.namespace
-      self.replace hash
+      hashes = [self.class.default_namespace, self.class.namespace].compact.map { |k| hash[k] || {} }
+      self.replace( hashes.size == 2 ? hash_deep_merge(*hashes) : hashes.first || hash )
     end
     @section = section || self.class.source  # so end of error says "in application.yml"
     create_accessors!
@@ -156,4 +164,14 @@ def #{key}
       end
     EndEval
   end
+
+  # http://api.rubyonrails.org/classes/ActiveSupport/CoreExtensions/Hash/DeepMerge.html
+  def hash_deep_merge(hash, other_hash)
+    hash.merge(other_hash) do |key, oldval, newval|
+      oldval = oldval.to_hash if oldval.respond_to?(:to_hash)
+      newval = newval.to_hash if newval.respond_to?(:to_hash)
+      oldval.class.to_s == 'Hash' && newval.class.to_s == 'Hash' ? self.hash_deep_merge(oldval, newval) : newval
+    end
+  end
+
 end

spec/settings2.yml

@@ -0,0 +1,33 @@
+defaults:
+  binaries:
+    git: /usr/bin/git
+    mysql: /usr/bin/mysql
+  deep:
+    level: 0
+    h1:
+      level: 1
+      h2:
+        level: 2
+        type: rgb
+        colors:
+          - red
+          - green
+          - blue
+
+production:
+  binaries:
+    mysql: /usr/bin/mysql51
+
+test:
+  deep:
+    h1:
+      list:
+        - a
+        - b
+      h2:
+        type: cmyk
+        colors:
+          - cyan
+          - magenta
+          - yellow
+          - black

spec/settings4.rb

@@ -0,0 +1,3 @@
+class Settings4 < Settingslogic
+  source "#{File.dirname(__FILE__)}/settings2.yml"
+end

spec/settingslogic_spec.rb

@@ -138,4 +138,138 @@ class NoSource < Settingslogic; end
   it "should be a hash" do
     Settings.send(:instance).should be_is_a(Hash)
   end
+
+  describe "without default_namespace and with namespace" do
+    it "should not merge settings from default_namespace" do
+      Settings4.instance_variable_set(:@default_namespace, nil)
+      Settings4.namespace('production')
+      Settings4.reload!
+
+      Settings4.to_hash.should == {
+        'binaries' => {
+          'mysql'     => "/usr/bin/mysql51",
+        }
+      }
+    end
+
+    it "should have empty settings if namespace does NOT exists" do
+      Settings4.instance_variable_set(:@default_namespace, nil)
+      Settings4.namespace('testing')
+      Settings4.reload!
+      Settings4.to_hash.should == { }
+    end
+  end
+
+  describe "with default_namespace and without namespace" do
+    it "should merge default_namespace and namespace settings" do
+      Settings4.default_namespace('defaults')
+      Settings4.instance_variable_set(:@namespace, nil)
+      Settings4.reload!
+
+      Settings4.to_hash.should == {
+        'binaries' => {
+          'git'       => "/usr/bin/git",
+          'mysql'     => "/usr/bin/mysql",
+        },
+        'deep'  => {
+          'level' => 0,
+          'h1' => {
+            'level' => 1,
+            'h2' => {
+              'level' => 2,
+              'type'  => 'rgb',
+              'colors' => %w(red green blue)
+            }
+          }
+        }
+      }
+    end
+
+    it "should have empty settings if defaults_namespace does NOT exists" do
+      Settings4.default_namespace('common')
+      Settings4.instance_variable_set(:@namespace, nil)
+      Settings4.reload!
+      Settings4.to_hash.should == { }
+    end
+  end
+
+  describe "with default_namespace and namespace" do
+    it "should merge default_namespace and namespace settings" do
+      Settings4.default_namespace('defaults')
+      Settings4.namespace('production')
+      Settings4.reload!
+
+      Settings4.to_hash.should == {
+        'binaries' => {
+          'git'       => "/usr/bin/git",
+          'mysql'     => "/usr/bin/mysql51",
+        },
+        'deep'  => {
+          'level' => 0,
+          'h1' => {
+            'level' => 1,
+            'h2' => {
+              'level' => 2,
+              'type'  => 'rgb',
+              'colors' => %w(red green blue)
+            }
+          }
+        }
+      }
+    end
+
+    it "should deep merge complex default_namespace and namespace settings" do
+      Settings4.default_namespace('defaults')
+      Settings4.namespace('test')
+      Settings4.reload!
+
+      Settings4.to_hash.should == {
+        'binaries' => {
+          'git'       => "/usr/bin/git",
+          'mysql'     => "/usr/bin/mysql",
+        },
+        'deep'  => {
+          'level' => 0,
+          'h1' => {
+            'list' => %w(a b),
+            'level' => 1,
+            'h2' => {
+              'level' => 2,
+              'type'  => 'cmyk',
+              'colors' => %w(cyan magenta yellow black)
+            }
+          }
+        }
+      }
+    end
+
+    it "should use custome namespace names" do
+      Settings4.default_namespace('production')
+      Settings4.namespace('test')
+      Settings4.reload!
+
+      Settings4.to_hash.should == {
+        'binaries' => {
+          'mysql'     => "/usr/bin/mysql51",
+        },
+        'deep'  => {
+          'h1' => {
+            'list' => %w(a b),
+            'h2' => {
+              'type'  => 'cmyk',
+              'colors' => %w(cyan magenta yellow black)
+            }
+          }
+        }
+      }
+    end
+
+    it "should have empty settings if defaults_namespace and namespace does NOT exist" do
+      Settings4.default_namespace('common')
+      Settings4.namespace('testing')
+      Settings4.reload!
+      Settings4.to_hash.should == { }
+    end
+  end
+
 end

spec/spec_helper.rb

@@ -8,6 +8,7 @@
 require 'settings'
 require 'settings2'
 require 'settings3'
+require 'settings4'
 
 # Needed to test Settings3
 Object.send :define_method, 'collides' do