Make Nokogiri::HTML::Document#meta_encoding= add a meta element if no…

…t present.
sparklemotion · Oct 30, 2013 · 86d1bfb · 86d1bfb
1 parent 050fb5c
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Showing 4 changed files with 80 additions and 14 deletions.
diff --git a/CHANGELOG.ja.rdoc b/CHANGELOG.ja.rdoc
@@ -11,7 +11,7 @@
   * (MRI) extconf.rb のオプション --use-system-libraries を追加
     環境変数 NOKOGIRI_USE_SYSTEM_LIBRARIES を設定する代わりに使える
   * (MRI) 同梱の libxslt を 1.1.28 に、 zlib を 1.2.8 に、 libiconv を 1.14 にそれぞれ更新した
-  * Nokogiri::HTML::Document#title= は、head要素がない場合でも常に、最適な場所を探しつつtitle要素を追加するようになった
+  * Nokogiri::HTML::Document#title= 及び #meta_encoding= は、head要素がない場合でも常に、最適な場所を探しつつ要素を追加するようになった
   * Nokogiri::XML::DTD#html_dtd? と #html5_dtd? を追加
   * Nokogiri::XML::Node#prepend_child を追加 #664
 

diff --git a/CHANGELOG.rdoc b/CHANGELOG.rdoc
@@ -18,9 +18,9 @@
     setting the environment variable NOKOGIRI_USE_SYSTEM_LIBRARIES.
   * (MRI) Update packaged libraries: libxslt to 1.1.28, zlib to 1.2.8,
     and libiconv to 1.14, respectively.
-  * Nokogiri::HTML::Document#title= now always add a title element
-    even if a head element is not present, trying hard to find the
-    best place to put it.
+  * Nokogiri::HTML::Document#title= and #meta_encoding= now always add
+    an element if not present, trying hard to find the best place to
+    put it.
   * Nokogiri::XML::DTD#html_dtd? and #html5_dtd? are added.
   * Nokogiri::XML::Node#prepend_child is added. #664
 

diff --git a/lib/nokogiri/html/document.rb b/lib/nokogiri/html/document.rb
@@ -14,11 +14,42 @@ def meta_encoding
       end
 
       ###
-      # Set the meta tag encoding for this document.  If there is no meta
-      # content tag, the encoding is not set.
+      # Set the meta tag encoding for this document.
+      #
+      # If an meta encoding tag is already present, its content is
+      # replaced with the given text.
+      #
+      # Otherwise, this method tries to create one at an appropriate
+      # place supplying head and/or html elements as necessary, which
+      # is inside a head element if any, and before any text node or
+      # content element (typically <body>) if any.
+      #
+      # The result when trying to set an encoding that is different
+      # from the document encoding is undefined.
       def meta_encoding= encoding
-        meta = meta_content_type and
-          meta['content'] = "text/html; charset=%s" % encoding
+        case
+        when meta = meta_content_type
+          meta['content'] = 'text/html; charset=%s' % encoding
+          encoding
+        when meta = at('//meta[@charset]')
+          meta['charset'] = encoding
+        else
+          meta = XML::Node.new('meta', self)
+          if dtd = internal_subset and dtd.html5_dtd?
+            meta['charset'] = encoding
+          else
+            meta['http-equiv'] = 'Content-Type'
+            meta['content'] = 'text/html; charset=%s' % encoding
+          end
+
+          case
+          when head = at('//head')
+            head.prepend_child(meta)
+          else
+            set_metadata_element(meta)
+          end
+          encoding
+        end
       end
 
       def meta_content_type
@@ -60,8 +91,19 @@ def title=(text)
         when meta = at('//meta[@charset]') || meta_content_type
           # better put after charset declaration
           meta.add_next_sibling(title)
+        else
+          set_metadata_element(title)
+        end
+        text
+      end
+
+      def set_metadata_element(element)
+        case
+        when head = at('//head')
+          head << element
         when html = at('//html')
-          html.prepend_child(XML::Node.new('head', self) << title)
+          head = html.prepend_child(XML::Node.new('head', self))
+          head.prepend_child(element)
         when first = children.find { |node|
             case node
             when XML::Element, XML::Text
@@ -71,12 +113,14 @@ def title=(text)
           # We reach here only if the underlying document model
           # allows <html>/<head> elements to be omitted and does not
           # automatically supply them.
-          first.add_previous_sibling(title)
+          first.add_previous_sibling(element)
         else
-          add_child(XML::Node.new('html', self) << (XML::Node.new('head', self) << title))
+          html = add_child(XML::Node.new('html', self))
+          head = html.add_child(XML::Node.new('head', self))
+          head.prepend_child(element)
         end
-        text
       end
+      private :set_metadata_element
 
       ####
       # Serialize Node using +options+.  Save options can also be set using a

diff --git a/test/html/test_document.rb b/test/html/test_document.rb
@@ -264,11 +264,33 @@ def test_title=()
       end
 
       def test_meta_encoding_without_head
-        html = Nokogiri::HTML('<html><body>foo</body></html>')
+        encoding = 'EUC-JP'
+        html = Nokogiri::HTML('<html><body>foo</body></html>', nil, encoding)
+
         assert_nil html.meta_encoding
 
-        html.meta_encoding = 'EUC-JP'
+        html.meta_encoding = encoding
+        assert_equal encoding, html.meta_encoding
+
+        meta = html.at('/html/head/meta[@http-equiv and boolean(@content)]')
+        assert meta, 'meta is in head'
+
+        assert meta.at('./parent::head/following-sibling::body'), 'meta is before body'
+      end
+
+      def test_html5_meta_encoding_without_head
+        encoding = 'EUC-JP'
+        html = Nokogiri::HTML('<!DOCTYPE html><html><body>foo</body></html>', nil, encoding)
+
         assert_nil html.meta_encoding
+
+        html.meta_encoding = encoding
+        assert_equal encoding, html.meta_encoding
+
+        meta = html.at('/html/head/meta[@charset]')
+        assert meta, 'meta is in head'
+
+        assert meta.at('./parent::head/following-sibling::body'), 'meta is before body'
       end
 
       def test_meta_encoding_with_empty_content_type