Added association inclusion in to_xml [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3831 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 111 insertions, 15 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index c3fdbe38c6..5cde7f465b 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -36,6 +36,33 @@
       <parent-id></parent-id>
       <last-read type="date">2004-04-15</last-read>
     </topic>
+  
+  You can even do load first-level associations as part of the document:
+  
+    firm.to_xml :include => [ :account, :clients ]
+  
+  ...that'll return something like:
+  
+    <?xml version="1.0" encoding="UTF-8"?>
+    <firm>
+      <id type="integer">1</id>
+      <rating type="integer">1</rating>
+      <name>37signals</name>
+      <clients>
+        <client>
+          <rating type="integer">1</rating>
+          <name>Summit</name>
+        </client>
+        <client>
+          <rating type="integer">1</rating>
+          <name>Microsoft</name>
+        </client>
+      </clients>
+      <account>
+        <id type="integer">1</id>
+        <credit-limit type="integer">50</credit-limit>
+      </account>
+    </firm>  
 
 * Allow :counter_cache to take a column name for custom counter cache columns [Jamis Buck]
 
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 61f7e94d89..c84f1c7778 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1418,8 +1418,24 @@ module ActiveRecord #:nodoc:
 
 
       # Returns a hash of all the attributes with their names as keys and clones of their objects as values.
-      def attributes
-        clone_attributes :read_attribute
+      def attributes(options = nil)
+        attributes = clone_attributes :read_attribute
+        
+        if options.nil?
+          attributes
+        else
+          if except = options[:except]
+            except = Array(except).collect { |attribute| attribute.to_s }
+            except.each { |attribute_name| attributes.delete(attribute_name) }
+            attributes
+          elsif only = options[:only]
+            only = Array(only).collect { |attribute| attribute.to_s }
+            attributes.delete_if { |key, value| !only.include?(key) }
+            attributes
+          else
+            raise ArgumentError, "Options does not specify :except or :only (#{options.keys.inspect})"
+          end
+        end
       end
 
       # Returns a hash of cloned attributes before typecasting and deserialization.
@@ -1506,16 +1522,31 @@ module ActiveRecord #:nodoc:
 
       # Turns this record into XML 
       def to_xml(options = {})
-        options[:skip_attributes] = Array(options[:skip_attributes])
-        options[:skip_attributes] << :type
-        options[:skip_attributes].collect! { |attribute| attribute.to_s }
-
-        attributes_to_be_xmled = attributes
-        options[:skip_attributes].each { |attribute_name| attributes_to_be_xmled.delete(attribute_name) }
-
         options[:root] ||= self.class.to_s.underscore
+        options[:except] = Array(options[:except]) << self.class.inheritance_column unless options[:only]
+        only_or_except   = { :only => options[:only], :except => options[:except] }
+
+        attributes_for_xml = attributes(only_or_except)
+        
+        if include_associations = options.delete(:include)
+          for association in Array(include_associations)
+            case self.class.reflect_on_association(association).macro
+              when :has_many, :has_and_belongs_to_many
+                records = send(association).to_a
+                unless records.empty?
+                  attributes_for_xml[association] = records.collect do |record| 
+                    record.attributes(only_or_except)
+                  end
+                end
+              when :has_one, :belongs_to
+                if record = send(association)
+                  attributes_for_xml[association] = record.attributes(only_or_except)
+                end
+            end
+          end
+        end
 
-        attributes_to_be_xmled.to_xml(options)
+        attributes_for_xml.to_xml(options)
       end
 
     private
diff --git a/activerecord/test/base_test.rb b/activerecord/test/base_test.rb
index d82bde433d..3ad2d6e960 100755
--- a/activerecord/test/base_test.rb
+++ b/activerecord/test/base_test.rb
@@ -1155,12 +1155,12 @@ class BasicsTest < Test::Unit::TestCase
   end
 
   def test_to_xml
-    xml = Topic.find(:first).to_xml(:indent => 0, :skip_instruct => true)
+    xml = topics(:first).to_xml(:indent => 0, :skip_instruct => true)
     assert_equal "<topic>", xml.first(7)
     assert xml.include?(%(<title>The First Topic</title>))
     assert xml.include?(%(<author-name>David</author-name>))
     assert xml.include?(%(<id type="integer">1</id>))
-    assert xml.include?(%(<approved type="boolean">false</approved>))
+    assert xml.include?(%(<approved type="boolean">false</approved>)), "Approved should be a boolean"
     assert xml.include?(%(<replies-count type="integer">0</replies-count>))
     assert xml.include?(%(<bonus-time type="datetime">2000-01-01 08:28:00</bonus-time>))
     assert xml.include?(%(<written-on type="datetime">2003-07-16 09:28:00</written-on>))
@@ -1171,16 +1171,54 @@ class BasicsTest < Test::Unit::TestCase
   end
   
   def test_to_xml_skipping_attributes
-    xml = Topic.find(:first).to_xml(:indent => 0, :skip_instruct => true, :skip_attributes => :title)
-    breakpoint
+    xml = topics(:first).to_xml(:indent => 0, :skip_instruct => true, :except => :title)
     assert_equal "<topic>", xml.first(7)
     assert !xml.include?(%(<title>The First Topic</title>))
     assert xml.include?(%(<author-name>David</author-name>))    
 
-    xml = Topic.find(:first).to_xml(:indent => 0, :skip_instruct => true, :skip_attributes => [ :title, :author_name ])
+    xml = topics(:first).to_xml(:indent => 0, :skip_instruct => true, :except => [ :title, :author_name ])
     assert !xml.include?(%(<title>The First Topic</title>))
     assert !xml.include?(%(<author-name>David</author-name>))    
   end
+  
+  def test_to_xml_including_has_many_association
+    xml = topics(:first).to_xml(:indent => 0, :skip_instruct => true, :include => :replies)
+    assert_equal "<topic>", xml.first(7)
+    assert xml.include?(%(<replies><reply>))
+    assert xml.include?(%(<title>The Second Topic's of the day</title>))
+  end
+
+  def test_to_xml_including_belongs_to_association
+    xml = companies(:first_client).to_xml(:indent => 0, :skip_instruct => true, :include => :firm)
+    assert !xml.include?("<firm>")
+
+    xml = companies(:second_client).to_xml(:indent => 0, :skip_instruct => true, :include => :firm)
+    assert xml.include?("<firm>")
+  end
+  
+  def test_to_xml_including_multiple_associations
+    xml = companies(:first_firm).to_xml(:indent => 0, :skip_instruct => true, :include => [ :clients, :account ])
+    assert_equal "<firm>", xml.first(6)
+    assert xml.include?(%(<account>))
+    assert xml.include?(%(<clients><client>))
+  end
+  
+  def test_except_attributes
+    assert_equal(
+      %w( author_name type id approved replies_count bonus_time written_on content author_email_address parent_id last_read), 
+      topics(:first).attributes(:except => :title).keys
+    )
+
+    assert_equal(
+      %w( replies_count bonus_time written_on content author_email_address parent_id last_read), 
+      topics(:first).attributes(:except => [ :title, :id, :type, :approved, :author_name ]).keys
+    )
+  end
+  
+  def test_include_attributes
+    assert_equal(%w( title ), topics(:first).attributes(:only => :title).keys)
+    assert_equal(%w( title author_name type id approved ), topics(:first).attributes(:only => [ :title, :id, :type, :approved, :author_name ]).keys)
+  end
 
   # FIXME: this test ought to run, but it needs to run sandboxed so that it
   # doesn't b0rk the current test environment by undefing everything.