Use XML::Attribute for element attributes.

Instead of using a raw Hash Oga now uses the XML::Attribute class for storing
information about element attributes.

Attributes are stored as an Array of XML::Attribute instances. This allows the
attributes to be more easily modified. If they were stored as a Hash you'd not
only have to update the attributes themselves but also the Hash that contains
them.

While using an Array has a slight runtime cost in most cases the amount of
attributes is small enough that this doesn't really pose a problem. If webscale
performance is desired at some point in the future Oga could most likely cache
the lookup of an attribute. This however is something for the future.

ext/ragel/base_lexer.rl

@@ -38,7 +38,6 @@
     newline    = '\n' | '\r\n';
     whitespace = [ \t];
     identifier = [a-zA-Z0-9\-_]+;
-    attribute  = [a-zA-Z0-9\-_:]+;
 
     # Comments
     #
@@ -144,7 +143,7 @@
         };
 
         # Attributes and their values (e.g. version="1.0").
-        attribute => {
+        identifier => {
             callback("on_attribute", data, encoding, ts, te);
         };
 
@@ -187,8 +186,12 @@
             callback_simple("advance_line");
         };
 
-        # Attribute names.
+        # Attribute names and namespaces.
-        attribute => {
+        identifier ':' => {
+            callback("on_attribute_ns", data, encoding, ts, te - 1);
+        };
+
+        identifier => {
             callback("on_attribute", data, encoding, ts, te);
         };
 

lib/oga/xml/element.rb

@@ -14,7 +14,7 @@ module Oga
     #
     # @!attribute [rw] attributes
     #  The attributes of the element.
-    #  @return [Hash]
+    #  @return [Array<Oga::XML::Attribute>]
     #
     class Element < Node
       attr_accessor :name, :namespace, :attributes
@@ -24,24 +24,38 @@ module Oga
       #
       # @option options [String] :name The name of the element.
       # @option options [String] :namespace The namespace of the element.
-      # @option options [Hash] :attributes The attributes of the element.
+      # @option options [Array<Oga::XML::Attribute>] :attributes The attributes
+      #  of the element as an Array.
       #
       def initialize(options = {})
         super
 
         @name       = options[:name]
         @namespace  = options[:namespace]
-        @attributes = options[:attributes] || {}
+        @attributes = options[:attributes] || []
       end
 
       ##
-      # Returns the value of the specified attribute.
+      # Returns the attribute of the given name.
+      #
+      # @example
+      #  # find an attribute that only has the name "foo"
+      #  attribute('foo')
+      #
+      #  # find an attribute with namespace "foo" and name bar"
+      #  attribute('foo:bar')
       #
       # @param [String] name
       # @return [String]
       #
       def attribute(name)
-        return attributes[name.to_sym]
+        name, ns = split_name(name)
+
+        attributes.each do |attr|
+          return attr if attribute_matches?(attr, ns, name)
+        end
+
+        return
       end
 
       alias_method :attr, :attribute
@@ -117,6 +131,38 @@ module Oga
       def node_type
         return :element
       end
+
+      private
+
+      ##
+      # @param [String] name
+      # @return [Array]
+      #
+      def split_name(name)
+        segments = name.to_s.split(':')
+
+        return segments.pop, segments.pop
+      end
+
+      ##
+      # @param [Oga::XML::Attribute] attr
+      # @param [String] ns
+      # @param [String] name
+      # @return [TrueClass|FalseClass]
+      #
+      def attribute_matches?(attr, ns, name)
+        name_matches = attr.name == name
+        ns_matches   = false
+
+        if ns
+          ns_matches = attr.namespace == ns
+
+        elsif name_matches
+          ns_matches = true
+        end
+
+        return name_matches && ns_matches
+      end
     end # Element
   end # XML
 end # Oga

lib/oga/xml/lexer.rb

@@ -354,6 +354,15 @@ module Oga
         end
       end
 
+      ##
+      # Called on attribute namespaces.
+      #
+      # @param [String] value
+      #
+      def on_attribute_ns(value)
+        add_token(:T_ATTR_NS, value)
+      end
+
       ##
       # Called on tag attributes.
       #

lib/oga/xml/parser.y

@@ -13,7 +13,7 @@ token T_STRING T_TEXT
 token T_DOCTYPE_START T_DOCTYPE_END T_DOCTYPE_TYPE T_DOCTYPE_NAME
 token T_DOCTYPE_INLINE
 token T_CDATA T_COMMENT
-token T_ELEM_START T_ELEM_NAME T_ELEM_NS T_ELEM_END T_ATTR
+token T_ELEM_START T_ELEM_NAME T_ELEM_NS T_ELEM_END T_ATTR T_ATTR_NS
 token T_XML_DECL_START T_XML_DECL_END
 
 options no_result_var
@@ -122,8 +122,8 @@ rule
   # Attributes
 
   attributes
-    : attributes_ { on_attributes(val[0]) }
+    : attributes_ { val[0] }
-    | /* none */  { {} }
+    | /* none */  { [] }
     ;
 
   attributes_
@@ -133,10 +133,22 @@ rule
 
   attribute
     # foo
-    : T_ATTR { {val[0].to_sym => nil} }
+    : attribute_name { val[0] }
 
     # foo="bar"
-    | T_ATTR T_STRING { {val[0].to_sym => val[1]} }
+    | attribute_name T_STRING
+      {
+        val[0].value = val[1]
+        val[0]
+      }
+    ;
+
+  attribute_name
+    # foo
+    : T_ATTR { Attribute.new(:name => val[0]) }
+
+    # foo:bar
+    | T_ATTR_NS T_ATTR { Attribute.new(:namespace => val[0], :name => val[1]) }
     ;
 
   # XML declarations
@@ -293,11 +305,17 @@ Unexpected #{name} with value #{value.inspect} on line #{@line}:
   end
 
   ##
-  # @param [Hash] attributes
+  # @param [Array] attributes
   # @return [Oga::XML::XmlDeclaration]
   #
-  def on_xml_decl(attributes = {})
+  def on_xml_decl(attributes = [])
-    return XmlDeclaration.new(attributes)
+    options = {}
+
+    attributes.each do |attr|
+      options[attr.name.to_sym] = attr.value
+    end
+
+    return XmlDeclaration.new(options)
   end
 
   ##
@@ -344,18 +362,4 @@ Unexpected #{name} with value #{value.inspect} on line #{@line}:
     return element
   end
 
-  ##
-  # @param [Array] pairs
-  # @return [Hash]
-  #
-  def on_attributes(pairs)
-    attrs = {}
-
-    pairs.each do |pair|
-      attrs = attrs.merge(pair)
-    end
-
-    return attrs
-  end
-
 # vim: set ft=racc:

spec/oga/xml/element_spec.rb

@@ -14,17 +14,50 @@ describe Oga::XML::Element do
     end
 
     example 'set the default attributes' do
-      described_class.new.attributes.should == {}
+      described_class.new.attributes.should == []
     end
   end
 
   context '#attribute' do
     before do
-      @instance = described_class.new(:attributes => {:key => 'value'})
+      attributes = [
+        Oga::XML::Attribute.new(:name => 'key', :value => 'value'),
+        Oga::XML::Attribute.new(
+          :name      => 'key',
+          :value     => 'foo',
+          :namespace => 'x'
+        )
+      ]
+
+      @instance = described_class.new(:attributes => attributes)
     end
 
-    example 'return an attribute' do
+    example 'return an attribute with only a name' do
-      @instance.attribute('key').should == 'value'
+      @instance.attribute('key').value.should == 'value'
+    end
+
+    example 'return an attribute with only a name when using a Symbol' do
+      @instance.attribute(:key).value.should == 'value'
+    end
+
+    example 'return an attribute with a name and namespace' do
+      @instance.attribute('x:key').value.should == 'foo'
+    end
+
+    example 'return an attribute with a name and namespace when using a Symbol' do
+      @instance.attribute(:'x:key').value.should == 'foo'
+    end
+
+    example 'return nil when the name matches but the namespace does not' do
+      @instance.attribute('y:key').nil?.should == true
+    end
+
+    example 'return nil when the namespace matches but the name does not' do
+      @instance.attribute('x:foobar').nil?.should == true
+    end
+
+    example 'return nil for a non existing attribute' do
+      @instance.attribute('foobar').nil?.should == true
     end
   end
 

spec/oga/xml/lexer/elements_spec.rb

@@ -78,7 +78,8 @@ describe Oga::XML::Lexer do
       lex('<p foo:bar="baz"></p>').should == [
         [:T_ELEM_START, nil, 1],
         [:T_ELEM_NAME, 'p', 1],
-        [:T_ATTR, 'foo:bar', 1],
+        [:T_ATTR_NS, 'foo', 1],
+        [:T_ATTR, 'bar', 1],
         [:T_STRING, 'baz', 1],
         [:T_ELEM_END, nil, 1]
       ]

spec/oga/xml/node_set_spec.rb

@@ -271,13 +271,14 @@ describe Oga::XML::NodeSet do
 
   context '#attribute' do
     before do
-      @el  = Oga::XML::Element.new(:name => 'a', :attributes => {:a => '1'})
+      @attr = Oga::XML::Attribute.new(:name => 'a', :value => '1')
+      @el   = Oga::XML::Element.new(:name => 'a', :attributes => [@attr])
       @txt  = Oga::XML::Text.new(:text => 'foo')
       @set  = described_class.new([@el, @txt])
     end
 
     example 'return the values of an attribute' do
-      @set.attribute('a').should == ['1']
+      @set.attribute('a').should == [@attr]
     end
   end
 

spec/oga/xml/parser/elements_spec.rb

@@ -43,7 +43,29 @@ describe Oga::XML::Parser do
     end
 
     example 'set the bar attribute' do
-      @element.attribute('bar').should == 'baz'
+      @element.attribute('bar').value.should == 'baz'
+    end
+  end
+
+  context 'elements with namespaced attributes' do
+    before :all do
+      @element = parse('<foo x:bar="baz"></foo>').children[0]
+    end
+
+    example 'return an Element instance' do
+      @element.is_a?(Oga::XML::Element).should == true
+    end
+
+    example 'include the namespace of the attribute' do
+      @element.attribute('x:bar').namespace.should == 'x'
+    end
+
+    example 'include the name of the attribute' do
+      @element.attribute('x:bar').name.should == 'bar'
+    end
+
+    example 'include the value of the attribute' do
+      @element.attribute('x:bar').value.should == 'baz'
     end
   end
 

spec/oga/xml/parser/html_void_elements_spec.rb

@@ -39,7 +39,7 @@ describe Oga::XML::Parser do
     end
 
     example 'set the attributes' do
-      @node.attributes.should == {:href => 'foo'}
+      @node.attribute('href').value.should == 'foo'
     end
   end
 end