Adds attribute protection to properties

Public Facing
   * through either :protected or :accessible8 flags
   * prevents protected attributes from being set in mass assignment
 Developer Facing
   * refactors #initialize and #update_attribute_without_saving
       to use same private methods to set attributes on ExtendedDocument
   * adds new mixin to do protection

Signed-off-by: Tapajós <tapajos@gmail.com>

.gitignore

@@ -1,3 +1,4 @@
 .DS_Store
 html/*
 pkg
+*.swp

lib/couchrest/mixins/attribute_protection.rb

@@ -0,0 +1,74 @@
+module CouchRest
+  module Mixins
+    module AttributeProtection
+      # Attribute protection from mass assignment to CouchRest properties
+      # 
+      # Protected methods will be removed from
+      #  * new 
+      #  * update_attributes
+      #  * upate_attributes_without_saving
+      #  * attributes=
+      #  
+      # There are two modes of protection
+      #  1) Declare accessible poperties, assume all the rest are protected 
+      #    property :name, :accessible => true
+      #    property :admin                     # this will be automatically protected
+      #
+      #  2) Declare protected properties, assume all the rest are accessible
+      #    property :name                      # this will not be protected
+      #    property :admin, :protected => true
+      #
+      # Note: you cannot set both flags in a single class
+      
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+
+      module ClassMethods
+        def accessible_properties
+          properties.select { |prop| prop.options[:accessible] }
+        end
+
+        def protected_properties
+          properties.select { |prop| prop.options[:protected] }
+        end
+      end
+
+      def accessible_properties
+        self.class.accessible_properties
+      end
+
+      def protected_properties
+        self.class.protected_properties
+      end
+
+      def remove_protected_attributes(attributes)
+        protected_names = properties_to_remove_from_mass_assignment.map { |prop| prop.name }
+        return attributes if protected_names.empty?
+
+        attributes.reject! do |key, value|
+          protected_names.include?(key.to_s)
+        end
+
+        attributes || {}
+      end
+
+      private
+
+      def properties_to_remove_from_mass_assignment
+        has_protected = !protected_properties.empty?
+        has_accessible = !accessible_properties.empty?
+
+        if !has_protected && !has_accessible
+          []
+        elsif has_protected && !has_accessible
+          protected_properties
+        elsif has_accessible && !has_protected
+          properties.reject { |prop| prop.options[:accessible] }
+        else
+          raise "Set either :accessible or :protected for #{self.class}, but not both"
+        end
+      end
+    end
+  end
+end

lib/couchrest/mixins/extended_document_mixins.rb

@@ -6,3 +6,4 @@ require File.join(File.dirname(__FILE__), 'validation')
 require File.join(File.dirname(__FILE__), 'extended_attachments')
 require File.join(File.dirname(__FILE__), 'class_proxy')
 require File.join(File.dirname(__FILE__), 'collection')
+require File.join(File.dirname(__FILE__), 'attribute_protection')

lib/couchrest/more/extended_document.rb

@@ -14,6 +14,7 @@ module CouchRest
     include CouchRest::Mixins::ExtendedAttachments
     include CouchRest::Mixins::ClassProxy
     include CouchRest::Mixins::Collection
+		include CouchRest::Mixins::AttributeProtection
 
     def self.subclasses
       @subclasses ||= []
@@ -40,11 +41,7 @@ module CouchRest
     
     def initialize(passed_keys={})
       apply_defaults # defined in CouchRest::Mixins::Properties
-      passed_keys.each do |k,v|
-        if self.respond_to?("#{k}=")
-          self.send("#{k}=", passed_keys.delete(k))
-        end
-      end if passed_keys
+			set_attributes(passed_keys)
       super
       cast_keys      # defined in CouchRest::Mixins::Properties
       unless self['_id'] && self['_rev']
@@ -150,12 +147,8 @@ module CouchRest
       # make a copy, we don't want to change arguments
       attrs = hash.dup
       %w[_id _rev created_at updated_at].each {|attr| attrs.delete(attr)}
-      attrs.each do |k, v|
-        raise NoMethodError, "#{k}= method not available, use property :#{k}" unless self.respond_to?("#{k}=")
-      end      
-      attrs.each do |k, v|
-        self.send("#{k}=",v)
-      end
+      check_properties_exist(attrs)
+			set_attributes(attrs)
     end
     alias :attributes= :update_attributes_without_saving
 
@@ -280,6 +273,22 @@ module CouchRest
         end
       end
     end
-    
+
+		private
+
+		def check_properties_exist(attrs)
+      attrs.each do |k, v|
+        raise NoMethodError, "#{k}= method not available, use property :#{k}" unless self.respond_to?("#{k}=")
+      end      
+		end
+
+		def set_attributes(hash)
+			attrs = remove_protected_attributes(hash)
+      attrs.each do |k,v|
+        if self.respond_to?("#{k}=")
+          self.send("#{k}=", attrs.delete(k))
+        end
+      end
+		end
   end
 end

spec/couchrest/more/attribute_protection_spec.rb

@@ -0,0 +1,94 @@
+require File.expand_path("../../../spec_helper", __FILE__)
+
+describe "ExtendedDocument", "no declarations" do
+  class NoProtection < CouchRest::ExtendedDocument
+    use_database TEST_SERVER.default_database
+    property :name
+    property :phone
+  end
+
+  it "should not protect anything through new" do
+    user = NoProtection.new(:name => "will", :phone => "555-5555")
+
+    user.name.should == "will"
+    user.phone.should == "555-5555"
+  end
+
+  it "should not protect anything through attributes=" do
+    user = NoProtection.new
+    user.attributes = {:name => "will", :phone => "555-5555"}
+
+    user.name.should == "will"
+    user.phone.should == "555-5555"
+  end
+end
+
+describe "ExtendedDocument", "accessible flag" do
+  class WithAccessible < CouchRest::ExtendedDocument
+    use_database TEST_SERVER.default_database
+    property :name, :accessible => true
+    property :admin, :default => false
+  end
+
+  it "should recognize accessible properties" do
+    props = WithAccessible.accessible_properties.map { |prop| prop.name}
+    props.should include("name")
+    props.should_not include("admin")
+  end
+
+  it "should protect non-accessible properties set through new" do
+    user = WithAccessible.new(:name => "will", :admin => true) 
+
+    user.name.should == "will"
+    user.admin.should == false
+  end
+
+  it "should protect non-accessible properties set through attributes=" do
+    user = WithAccessible.new
+    user.attributes = {:name => "will", :admin => true}
+
+    user.name.should == "will"
+    user.admin.should == false
+  end
+end
+
+describe "ExtendedDocument", "protected flag" do
+  class WithProtected < CouchRest::ExtendedDocument
+    use_database TEST_SERVER.default_database
+    property :name
+    property :admin, :default => false, :protected => true
+  end
+
+  it "should recognize protected properties" do
+    props = WithProtected.protected_properties.map { |prop| prop.name}
+    props.should_not include("name")
+    props.should include("admin")
+  end
+
+  it "should protect non-accessible properties set through new" do
+    user = WithProtected.new(:name => "will", :admin => true) 
+
+    user.name.should == "will"
+    user.admin.should == false
+  end
+
+  it "should protect non-accessible properties set through attributes=" do
+    user = WithProtected.new
+    user.attributes = {:name => "will", :admin => true}
+
+    user.name.should == "will"
+    user.admin.should == false
+  end
+end
+
+describe "ExtendedDocument", "protected flag" do
+  class WithBoth < CouchRest::ExtendedDocument
+    use_database TEST_SERVER.default_database
+    property :name, :accessible => true
+    property :admin, :default => false, :protected => true
+  end
+
+  it "should raise an error when both are set" do
+    lambda { WithBoth.new }.should raise_error 
+  end
+end