Make respond_to? work as expected

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6657 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 28 insertions, 0 deletions

diff --git a/activeresource/lib/active_resource/base.rb b/activeresource/lib/active_resource/base.rb
index d2253186b0..0f147acad9 100644
--- a/activeresource/lib/active_resource/base.rb
+++ b/activeresource/lib/active_resource/base.rb
@@ -316,6 +316,26 @@ module ActiveResource
       end
       self
     end
+    
+    # For checking respond_to? without searching the attributes (which is faster).
+    alias_method :respond_to_without_attributes?, :respond_to?
+
+    # A Person object with a name attribute can ask person.respond_to?("name"), person.respond_to?("name="), and
+    # person.respond_to?("name?") which will all return true.
+    def respond_to?(method, include_priv = false)
+      method_name = method.to_s
+      if attributes.nil?
+        return super
+      elsif attributes.has_key?(method_name)
+        return true 
+      elsif ['?','='].include?(method_name.last) && attributes.has_key?(method_name.first(-1))
+        return true
+      end
+      # super must be called at the end of the method, because the inherited respond_to?
+      # would return true for generated readers, even if the attribute wasn't present
+      super
+    end
+    
 
     protected
       def connection(refresh = false)
diff --git a/activeresource/test/base_test.rb b/activeresource/test/base_test.rb
index 6a6ee5c64b..e9bf5d70b3 100644
--- a/activeresource/test/base_test.rb
+++ b/activeresource/test/base_test.rb
@@ -178,6 +178,14 @@ class BaseTest < Test::Unit::TestCase
     assert_kind_of Person, matz
     assert_equal "Matz", matz.name
   end
+  
+  def test_respond_to
+    matz = Person.find(1)
+    assert matz.respond_to?(:name)
+    assert matz.respond_to?(:name=)
+    assert matz.respond_to?(:name?)
+    assert !matz.respond_to?(:java)
+  end
 
   def test_find_by_id_with_custom_prefix
     addy = StreetAddress.find(1, :params => { :person_id => 1 })