html: support [:html, :condcomment, ...]

CHANGES

@@ -1,6 +1,7 @@
 master
 
   * Set tilt template default_mime_type to text/html
+  * HTML: Support conditional comments [:html, :condcomment, ...]
 
 0.4.0
 

EXPRESSIONS.md

@@ -210,6 +210,13 @@ Example:
 generates:
     <!--comment-->
 
+### [:html, :condcomment, condition, sexp]
+
+Example:
+    [:html, :condcomment, 'IE', [:static, 'comment']]
+generates:
+    <!--[if IE]>comment<![endif]-->
+
 ### [:html, :tag, identifier, attributes, optional-sexp]
 
 HTML tag abstraction. Identifier can be a String or a Symbol. If the optional content Sexp is omitted

lib/temple/grammar.rb

@@ -29,6 +29,7 @@ module Grammar
       # HTML abstraction
       [:html, :doctype, String]                |
       [:html, :comment, Expression]            |
+      [:html, :condcomment, String, Expression]|
       [:html, :tag, HTMLIdentifier, Expression, 'Expression?'] |
       [:html, :attrs, 'HTMLAttr*']             |
       HTMLAttr

lib/temple/html/dispatcher.rb

@@ -14,6 +14,10 @@ def on_html_comment(content)
         [:html, :comment, compile(content)]
       end
 
+      def on_html_condcomment(condition, content)
+        [:html, :condcomment, condition, compile(content)]
+      end
+
       def on_html_tag(name, attrs, content = nil)
         result = [:html, :tag, name, compile(attrs)]
         content ? (result << compile(content)) : result

lib/temple/html/fast.rb

@@ -65,6 +65,13 @@ def on_html_comment(content)
           [:static, '-->']]
       end
 
+      def on_html_condcomment(condition, content)
+        on_html_comment [:multi,
+                         [:static, "[#{condition}]>"],
+                         content,
+                         [:static, '<![endif]']]
+      end
+
       def on_html_tag(name, attrs, content = nil)
         name = name.to_s
         closed = !content || (empty_exp?(content) && options[:autoclose].include?(name))