Nokogiri backend for XmlMini

[#2190 state:committed]
Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activesupport/CHANGELOG

 *Edge*
 
-* XmlMini supports libxml if available.  #2084 [Bart ten Brinke]
+* XmlMini supports LibXML and Nokogiri backends.  #2084, #2190 [Bart ten Brinke, Aaron Patterson]
+    Example: XmlMini.backend = 'Nokogiri'
 
 
 *2.3.1 [RC2] (March 5, 2009)*

activesupport/lib/active_support/xml_mini.rb

@@ -8,6 +8,10 @@ module XmlMini
     extend self
     delegate :parse, :to => :@backend
 
+    class << self
+      attr_reader :backend
+    end
+
     def backend=(name)
       require "active_support/xml_mini/#{name.to_s.downcase}.rb"
       @backend = ActiveSupport.const_get("XmlMini_#{name}")

activesupport/lib/active_support/xml_mini/nokogiri.rb

+# = XML Mini Nokogiri implementation
+module ActiveSupport
+  module XmlMini_Nokogiri #:nodoc:
+    extend self
+
+    # Parse an XML Document string into a simple hash using libxml / nokogiri.
+    # string::
+    #   XML Document string to parse
+    def parse(string)
+      return {} if string.blank?
+      doc = Nokogiri::XML(string).to_hash
+    end
+
+    module Conversions
+      module Document
+        def to_hash
+          root.to_hash
+        end
+      end
+
+      module Node
+        CONTENT_ROOT = '__content__'
+
+        # Convert XML document to hash
+        #
+        # hash::
+        #   Hash to merge the converted element into.
+        def to_hash(hash = {})
+          hash[name] ||= attributes_as_hash
+
+          walker = lambda { |child, memo, callback|
+            next if child.blank?
+
+            if child.text?
+              (memo[CONTENT_ROOT] ||= '') << child.content
+              next
+            end
+
+            name = child.name
+
+            if memo[name]
+              memo[name] = [memo[name]].flatten
+              memo[name] << child.attributes_as_hash
+            else
+              memo[name] = child.attributes_as_hash
+            end
+
+            # Recusively walk children
+            child.children.each { |c| callback.call(c, memo[name], callback) }
+          }
+
+          children.each { |c| walker.call(c, hash[name], walker) }
+          hash
+        end
+
+        def attributes_as_hash
+          Hash[*(attribute_nodes.map { |node|
+            [node.node_name, node.value]
+          }.flatten)]
+        end
+      end
+    end
+
+    Nokogiri::XML::Document.send(:include, Conversions::Document)
+    Nokogiri::XML::Node.send(:include, Conversions::Node)
+  end
+end

activesupport/test/xml_mini/nokogiri_engine_test.rb

+require 'abstract_unit'
+require 'active_support/xml_mini'
+
+
+begin
+
+require 'nokogiri'
+
+class NokogiriEngineTest < Test::Unit::TestCase
+  include ActiveSupport
+
+  def setup
+    @default_backend = XmlMini.backend.to_s.split('_').last
+    XmlMini.backend = 'Nokogiri'
+  end
+
+  def teardown
+    XmlMini.backend = @default_backend
+  end
+
+  def test_setting_nokogiri_as_backend
+    XmlMini.backend = 'Nokogiri'
+    assert_equal XmlMini_Nokogiri, XmlMini.backend
+  end
+
+  def test_blank_returns_empty_hash
+    assert_equal({}, XmlMini.parse(nil))
+    assert_equal({}, XmlMini.parse(''))
+  end
+
+  def test_one_node_document_as_hash
+    assert_equal_rexml(<<-eoxml)
+    <products/>
+    eoxml
+  end
+
+  def test_one_node_with_attributes_document_as_hash
+    assert_equal_rexml(<<-eoxml)
+    <products foo="bar"/>
+    eoxml
+  end
+
+  def test_products_node_with_book_node_as_hash
+    assert_equal_rexml(<<-eoxml)
+    <products>
+      <book name="awesome" id="12345" />
+    </products>
+    eoxml
+  end
+
+  def test_products_node_with_two_book_nodes_as_hash
+    assert_equal_rexml(<<-eoxml)
+    <products>
+      <book name="awesome" id="12345" />
+      <book name="america" id="67890" />
+    </products>
+    eoxml
+  end
+
+  def test_single_node_with_content_as_hash
+    assert_equal_rexml(<<-eoxml)
+      <products>
+        hello world
+      </products>
+    eoxml
+  end
+
+  def test_children_with_children
+    assert_equal_rexml(<<-eoxml)
+    <root>
+      <products>
+        <book name="america" id="67890" />
+      </products>
+    </root>
+    eoxml
+  end
+
+  def test_children_with_text
+    assert_equal_rexml(<<-eoxml)
+    <root>
+      <products>
+        hello everyone
+      </products>
+    </root>
+    eoxml
+  end
+
+  def test_children_with_non_adjacent_text
+    assert_equal_rexml(<<-eoxml)
+    <root>
+      good
+      <products>
+        hello everyone
+      </products>
+      morning
+    </root>
+    eoxml
+  end
+
+  private
+  def assert_equal_rexml(xml)
+    XmlMini.backend = 'REXML'
+    hash = XmlMini.parse(xml)
+
+    XmlMini.backend = 'Nokogiri'
+
+    assert_equal(hash, XmlMini.parse(xml))
+  end
+end
+rescue LoadError
+  # Yay, no errors
+end

activesupport/test/xml_mini/rexml_engine_test.rb

+require 'abstract_unit'
+require 'active_support/xml_mini'
+
+class REXMLEngineTest < Test::Unit::TestCase
+  include ActiveSupport
+
+  def test_default_is_rexml
+    assert_equal XmlMini_REXML, XmlMini.backend
+  end
+
+  def test_set_rexml_as_backend
+    XmlMini.backend = 'REXML'
+    assert_equal XmlMini_REXML, XmlMini.backend
+  end
+end