Added the Tire::Model::DynamicPersistence extension

Related: karmi/retire#605

Closes #14

README.markdown

@@ -15,6 +15,10 @@ Then require the component you want to use in your application initializer. For
 See specific files and folders inside the `lib/tire` folder for instructions and documentation.
 
 
+### Dynamic Persistence ###
+
+Adds support for dynamic attributes when using Tire::Model::Persistence so that model properties no longer need to be declared explicitly. [More info](lib/tire/model/dynamic_persistence).
+
 ### More Like This Queries ###
 
 Adds support for [“more like this”](http://www.elasticsearch.org/guide/reference/query-dsl/mlt-query.html) queries.

lib/tire/model/dynamic_persistence.rb

@@ -0,0 +1,34 @@
+# Dynamic Persistence
+# ===================
+#
+# Author: Dave Kinkead <dave@kinkead.com.au>
+#
+#
+# Adds support for dynamic persistence to Tire::Model::Persistence so that explict 
+#   declarations of 'property :attr_name' are not required
+#
+#
+# Usage:
+# ------
+#
+# Require the component:
+#
+#     require 'tire/model/dynamic_persistence'
+#
+# Example:
+# -------
+#
+#     class Author
+#
+#       include Tire::Model::Persistence
+#       include Tire::Model::DynamicPersistence
+#     end
+#
+#     author = Author.new :name => 'Inigo Montoya', 
+#                         :books => ['The Pragmatic Swordfighter', 'Revenge: Best Served Cold']
+#
+#     author.name 
+#     # => 'Inigo Montoya'
+#
+#
+require 'tire/model/dynamic_persistence/dynamic_persistence'

lib/tire/model/dynamic_persistence/README.markdown

@@ -0,0 +1,28 @@
+# Dynamic Persistence
+
+Adds support for truly dynamic persistence models so that you no longer have to explicitly declare properties.
+
+Very useful if you want to create models on the fly.
+
+## Usage
+
+Require the module in your model file
+
+	require 'tire/model/dynamic_persistence'
+
+Include Persistence and DynamicPersistence
+
+	 class Author
+
+	   include Tire::Model::Persistence
+	   include Tire::Model::DynamicPersistence
+	 end
+
+Then create your model by passing it a hash of key:value pairs
+
+	 author = Author.new :name => 'Inigo Montoya', 
+	                     :books => ['The Pragmatic Swordfighter', 'Revenge: Best Served Cold']
+
+	 author.name 
+	 # => 'Inigo Montoya'
+

lib/tire/model/dynamic_persistence/dynamic_persistence.rb

@@ -0,0 +1,21 @@
+require 'tire'
+
+module Tire
+  module Model
+    module DynamicPersistence
+
+      # Overrides the initializer in Tire::Model::Persistence to allow
+      #   dynamic creation of attributes without the need to 
+      #   declare them with 'property :name'
+      def initialize(attrs={})
+        attrs.each do |attr, value|
+          # => call Tire's property method if it hasn't been set
+          self.class.property attr unless self.class.property_types.keys.include? attr
+          # => set instance variable
+          instance_variable_set("@#{attr}", value) 
+        end
+        super attrs             
+      end
+    end
+  end
+end

test/dynamic_persistence/dynamic_persistence_test.rb

@@ -0,0 +1,26 @@
+require 'test_helper'
+
+module Tire
+  module Model
+
+    class DynamicPersistenceTest < Test::Unit::TestCase
+
+      context "Persistent model with dynamic creation" do
+
+        should "permit access to attrs passed to create" do 
+          @article = PersistentArticleWithDynamicCreation.new :name => 'Elasticsearch', :title => 'You know, for Search!'
+          assert_equal @article.name, 'Elasticsearch'
+        end
+
+        should "not override explicit persistent properties" do
+          @article = PersistentArticleWithDynamicCreation.new :name => 'Elasticsearch', :author => { :name => 'Inigo Montoya' }
+          assert_equal @article.author.name, 'Inigo Montoya'
+          assert_equal @article.tags.class, Array
+          assert_equal @article.tags.length, 0
+        end
+
+      end
+
+    end
+  end
+end