Add Stacked Configuration Files Feature

.gitignore

@@ -8,3 +8,4 @@ benchmarks/*
 .bundle
 vendor/bundle
 .rvmrc
+Gemfile.lock

Gemfile

@@ -1,2 +1,2 @@
-source :rubygems
+source 'https://rubygems.org'
 gemspec

lib/settingslogic.rb

@@ -1,6 +1,7 @@
 require "yaml"
 require "erb"
 require 'open-uri'
+require 'hash_deep_merge'
 
 # A simple settings solution using a YAML file. See README for more information.
 class Settingslogic < Hash
@@ -10,7 +11,7 @@ class << self
     def name # :nodoc:
       self.superclass != Hash && instance.key?("name") ? instance.name : super
     end
-        
+
     # Enables Settings.get('nested.key.name') for dynamic access
     def get(key)
       parts = key.split('.')
@@ -22,7 +23,45 @@ def get(key)
     end
 
     def source(value = nil)
-      @source ||= value
+      if value.is_a?(Array)
+        @source = flatten_stacked_settings_to_hash(value)
+      else
+        @source ||= value
+      end
+    end
+
+    # If initialize was given an array of settings, use deep merge to flatten
+    # all settings into one hash, where the last processed setting is chosen
+    def flatten_stacked_settings_to_hash (array_of_settings)
+      resulting_hash = Hash.new
+      array_of_settings.each do |settings|
+        new_hash = nil
+        case settings
+
+        when Hash
+          new_hash = settings
+
+        when String  # assume it's a filename...
+          begin
+            file_contents = open(settings).read
+            new_hash = file_contents.empty? ? {} : YAML.load(ERB.new(file_contents).result).to_hash
+          rescue
+          end
+
+        else
+          new_hash = (settings.to_hash rescue nil)
+        end
+
+        #continue if empty
+        next if new_hash.empty?
+
+        if new_hash.is_a?(Hash)
+          resulting_hash.deep_merge!(new_hash)
+        else
+          puts "ExtendedSettings WARN : unable to add settings object : #{ settings.inspect}"
+        end
+      end
+      resulting_hash
     end
 
     def namespace(value = nil)
@@ -92,7 +131,6 @@ def create_accessor_for(key)
   # if you are using this in rails. If you pass a string it should be an absolute path to your settings file.
   # Then you can pass a hash, and it just allows you to access the hash via methods.
   def initialize(hash_or_file = self.class.source, section = nil)
-    #puts "new! #{hash_or_file}"
     case hash_or_file
     when nil
       raise Errno::ENOENT, "No file specified as Settingslogic source"
@@ -106,7 +144,7 @@ def initialize(hash_or_file = self.class.source, section = nil)
       end
       self.replace hash
     end
-    @section = section || self.class.source  # so end of error says "in application.yml"
+    @section = section || self.class.source.to_yaml # so end of error says "in application.yml"
     create_accessors!
   end
 
@@ -167,25 +205,24 @@ def #{key}
       end
     EndEval
   end
-  
+
   def symbolize_keys
-    
+
     inject({}) do |memo, tuple|
-      
+
       k = (tuple.first.to_sym rescue tuple.first) || tuple.first
-            
+
       v = k.is_a?(Symbol) ? send(k) : tuple.last # make sure the value is accessed the same way Settings.foo.bar works
-      
+
       memo[k] = v && v.respond_to?(:symbolize_keys) ? v.symbolize_keys : v #recurse for nested hashes
-      
+
       memo
     end
-    
+
   end
-  
+
   def missing_key(msg)
     return nil if self.class.suppress_errors
-
     raise MissingSetting, msg
   end
 end

settingslogic.gemspec

@@ -13,6 +13,10 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec'
+  s.add_development_dependency 'pry'
+  s.add_development_dependency 'ruby-debug'
+
+  s.add_dependency 'hash-deep-merge', '~> 0.1.1'
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")

spec/settings2.yml

@@ -0,0 +1,31 @@
+setting1:
+  setting1_child: saweeter
+  deep:
+    another: my value
+    child:
+      value: 4
+
+setting2: 5
+setting3: <%= 5 * 5 %>
+name: test is gone
+
+language:
+  haskell:
+    paradigm: functional
+  smalltalk:
+    paradigm: object oriented
+
+collides:
+  does: not
+nested:
+  collides:
+    does: not either
+
+new_stuff:
+  because: testing has to happen
+
+array:
+  -
+    name: first
+  -
+    name: second

spec/settingslogic_spec.rb

@@ -4,11 +4,11 @@
   it "should access settings" do
     Settings.setting2.should == 5
   end
-  
+
   it "should access nested settings" do
     Settings.setting1.setting1_child.should == "saweet"
   end
-  
+
   it "should access settings in nested arrays" do
     Settings.array.first.name.should == "first"
   end
@@ -39,7 +39,7 @@
     Settings.language.haskell.paradigm.should == 'functional'
     Settings.language.smalltalk.paradigm.should == 'object oriented'
   end
-  
+
   it "should not collide with global methods" do
     Settings3.nested.collides.does.should == 'not either'
     Settings3[:nested] = 'fooey'
@@ -77,7 +77,7 @@
     end
     e.should_not be_nil
     e.message.should =~ /Missing setting 'erlang' in 'language' section/
-    
+
     Settings.language['erlang'].should be_nil
     Settings.language['erlang'] = 5
     Settings.language['erlang'].should == 5
@@ -168,14 +168,14 @@ class NoSource < Settingslogic; end
   it "should allow a name setting to be overriden" do
     Settings.name.should == 'test'
   end
-  
+
   it "should allow symbolize_keys" do
     Settings.reload!
-    result = Settings.language.haskell.symbolize_keys 
+    result = Settings.language.haskell.symbolize_keys
     result.class.should == Hash
-    result.should == {:paradigm => "functional"} 
+    result.should == {:paradigm => "functional"}
   end
-  
+
   it "should allow symbolize_keys on nested hashes" do
     Settings.reload!
     result = Settings.language.symbolize_keys
@@ -203,5 +203,28 @@ class NoSource < Settingslogic; end
       Settings.to_hash.object_id.should_not == Settings.object_id
     end
   end
-
+  describe "providing mulitple configuration sources" do
+    describe "#flatten_stacked_settings_to_hash" do
+      it "returns a hash from mulitple sources" do
+        configs = [
+            "#{File.dirname(__FILE__)}/settings.yml",
+            "#{File.dirname(__FILE__)}/settings_empty.yml",
+            "#{File.dirname(__FILE__)}/settings2.yml"]
+        StackedSettings.flatten_stacked_settings_to_hash(configs)
+          .is_a?(Hash).should == true
+      end
+      it "returns the last setting for each configuration attributed" do
+        StackedSettings.setting1.setting1_child.should == 'saweeter'
+      end
+      it "adds new settings from secondary sources" do
+        StackedSettings.new_stuff.because.should == "testing has to happen"
+      end
+      it "keeps the latest setting for each variable" do
+        StackedSettings.language.haskell.paradigm.should == 'functional'
+      end
+      it "accepts a hash as a source" do
+        StackedSettings.setting2.should == 10
+      end
+    end
+  end
 end

spec/spec_helper.rb

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

spec/stacked_settings.rb

@@ -0,0 +1,7 @@
+class StackedSettings < Settingslogic
+  source ["#{File.dirname(__FILE__)}/settings.yml",
+      "#{File.dirname(__FILE__)}/settings_empty.yml",
+      "#{File.dirname(__FILE__)}/settings2.yml",
+      {"setting2" => 10}]
+  load!
+end